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How much do we know about schizophrenia and how well do we know it? Evidence from the Schizophrenia Library

  • S. L. Matheson (a1) (a2), A. M. Shepherd (a1) (a2) and V. J. Carr (a1) (a2)

Abstract

Background.

True findings about schizophrenia remain elusive; many findings are not replicated and conflicting results are common. Well-conducted systematic reviews have the ability to make robust, generalizable conclusions, with good meta-analyses potentially providing the closest estimate of the true effect size. In this paper, we undertake a systematic approach to synthesising the available evidence from well-conducted systematic reviews on schizophrenia.

Method.

Reviews were identified by searching Medline, EMBASE, CINAHL, Current Contents and PsycINFO. The decision to include or exclude reviews, data extraction and quality assessments were conducted in duplicate. Evidence was graded as high quality if reviews contained large samples and robust results; and as moderate quality if reviews contained imprecision, inconsistency, smaller samples or study designs that may be prone to bias.

Results.

High- and moderate-quality evidence shows that numerous psychosocial and biomedical treatments are effective. Patients have relatively poor cognitive functioning, and subtle, but diverse, structural brain alterations, altered electrophysiological functioning and sleep patterns, minor physical anomalies, neurological soft signs, and sensory alterations. There are markers of infection, inflammation or altered immunological parameters; and there is increased mortality from a range of causes. Risk for schizophrenia is increased with cannabis use, pregnancy and birth complications, prenatal exposure to Toxoplasma gondii, childhood central nervous system viral infections, childhood adversities, urbanicity and immigration (first and second generation), particularly in certain ethnic groups. Developmental motor delays and lower intelligence quotient in childhood and adolescence are apparent.

Conclusions.

We conclude that while our knowledge of schizophrenia is very substantial, our understanding of it remains limited.

Copyright

Corresponding author

* Address for correspondence: S. L. Matheson, M.P.H., UNSW Research Unit for Schizophrenia Epidemiology, O'Brien Centre, Level 4, St Vincent's Hospital, 394–404 Victoria Street, Darlinghurst, NSW 2010, Australia. (Email: s.matheson@schizophreniaresearch.org.au)

References

Hide All
Achim, AM, Lepage, M (2005). Episodic memory-related activation in schizophrenia: meta-analysis. British Journal of Psychiatry 187, 500509.
Achim, AM, Maziade, M, Raymond, E, Olivier, D, Merette, C, Roy, M (2011). How prevalent are anxiety disorders in schizophrenia? A meta-analysis and critical review on a significant association. Schizophrenia Bulletin 37, 811821.
Adams, CE, Awad, G, Rathbone, J, Thornley, B (2007). Chlorpromazine versus placebo for schizophrenia. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD000284. doi:10.1002/14651858.CD000284.pub2.
Adriano, F, Caltagirone, C, Spalletta, G (2012). Hippocampal volume reduction in first-episode and chronic schizophrenia: a review and meta-analysis. Neuroscientist 18, 180200.
Adriano, F, Spoletini, I, Caltagirone, C, Spalletta, G (2010). Updated meta-analyses reveal thalamus volume reduction in patients with first-episode and chronic schizophrenia. Schizophrenia Research 123, 14.
Aleman, A, Agrawal, N, Morgan, KD, David, AS (2006). Insight in psychosis and neuropsychological function: meta-analysis. British Journal of Psychiatry 189, 204212.
Aleman, A, Sommer, IE, Kahn, RS (2007). Efficacy of slow repetitive transcranial magnetic stimulation in the treatment of resistant auditory hallucinations in schizophrenia: a meta-analysis. Journal of Clinical Psychiatry 68, 416421.
Allen, NC, Bagade, S, McQueen, MB, Ioannidis, JPA, Kavvoura, FK, Khoury, MJ, Tanzi, RE, Bertram, L (2008). Systematic meta-analyses and field synopsis of genetic association studies in schizophrenia: the SzGene database. Nature Genetics 40, 827834.
Alvarez-Jimenez, M, Parker, AG, Hetrick, SE, McGorry, PD, Gleeson, JF (2011). Preventing the second episode: a systematic review and meta-analysis of psychosocial and pharmacological trials in first-episode psychosis. Schizophrenia Bulletin 37, 619630.
Alvarez-Jimenez, M, Priede, A, Hetrick, SE, Bendall, S, Killackey, E, Parker, AG, McGorry, PD, Gleeson, JF (2012). Risk factors for relapse following treatment for first episode psychosis: a systematic review and meta-analysis of longitudinal studies. Schizophrenia Research 139, 116128.
Anderson, KK, Fuhrer, R, Malla, AK (2010). The pathways to mental health care of first-episode psychosis patients: a systematic review. Psychological Medicine 40, 15851597.
Anticevic, A, Van Snellenberg, JX, Cohen, RE, Repovs, G, Dowd, EC, Barch, DM (2012). Amygdala recruitment in schizophrenia in response to aversive emotional material: a meta-analysis of neuroimaging studies. Schizophrenia Bulletin 38, 608621.
Arias, I, Sorlozano, A, Villegas, E, de Dios Luna, J, McKenney, K, Cervilla, J, Gutierrez, B, Gutierrez, J (2011). Infectious agents associated with schizophrenia: a meta-analysis. Schizophrenia Research 136, 128136.
Arnone, D, McIntosh, AM, Tan, GM, Ebmeier, KP, Tan, GMY (2008). Meta-analysis of magnetic resonance imaging studies of the corpus callosum in schizophrenia. Schizophrenia Research 101, 124132.
Baiano, M, David, A, Versace, A, Churchill, R, Balestrieri, M, Brambilla, P (2007). Anterior cingulate volumes in schizophrenia: a systematic review and a meta-analysis of MRI studies. Schizophrenia Research 93, 112.
Beauchamp, G, Gagnon, A (2004). Influence of diagnostic classification on gender ratio in schizophrenia – a meta-analysis of youths hospitalized for psychosis. Social Psychiatry and Psychiatric Epidemiology 39, 10171022.
Begemann, MJH, Dekker, CF, van Lunenburg, M, Sommer, IE (2012). Estrogen augmentation in schizophrenia: a quantitative review of current evidence. Schizophrenia Research 141, 179184.
Belgamwar, RB, El-Sayeh, HGG (2011). Aripiprazole versus placebo for schizophrenia. Cochrane Database of Systematic Reviews, Issue 8. Art. No.: CD006622. doi:10.1002/14651858.CD006622.pub2.
Berger, GE, Wood, SJ, Pantelis, C, Velakoulis, D, Wellard, RM, McGorry, PD (2002). Implications of lipid biology for the pathogenesis of schizophrenia. Australian and New Zealand Journal of Psychiatry 36, 355366.
Bird, V, Premkumar, P, Kendall, T, Whittington, C, Mitchell, J, Kuipers, E (2010). Early intervention services, cognitive-behavioural therapy and family intervention in early psychosis: systematic review. British Journal of Psychiatry 197, 350356.
Bokat, CE, Goldberg, TE (2003). Letter and category fluency in schizophrenic patients: a meta-analysis. Schizophrenia Research 64, 7378.
Boonstra, N, Klaassen, R, Sytema, S, Marshall, M, De Haan, L, Wunderink, L, Wiersma, D (2012). Duration of untreated psychosis and negative symptoms – a systematic review and meta-analysis of individual patient data. Schizophrenia Research 142, 1219.
Bora, E, Fornito, A, Radua, J, Walterfang, M, Seal, M, Wood, SJ, Yücel, M, Velakoulis, D, Pantelis, C (2011). Neuroanatomical abnormalities in schizophrenia: a multimodal voxelwise meta-analysis and meta-regression analysis. Schizophrenia Research 127, 4657.
Bora, E, Pantelis, C (2013). Theory of mind impairments in first-episode psychosis, individuals at ultra-high risk for psychosis and in first-degree relatives of schizophrenia: systematic review and meta-analysis. Schizophrenia Research 144, 3136.
Bora, E, Yucel, M, Pantelis, C (2009 a). Theory of mind impairment in schizophrenia: meta-analysis. Schizophrenia Research 109, 19.
Bora, E, Yucel, M, Pantelis, C (2009 b). Cognitive functioning in schizophrenia, schizoaffective disorder and affective psychoses: meta-analytic study. British Journal of Psychiatry 195, 475482.
Borenstein, M, Hedges, LV, Higgins, JPT, Rothstein, HR (2009). Introduction to Meta-Analysis. John Wiley and Sons: Chichester.
Bourque, F, van der Ven, E, Malla, A (2011). A meta-analysis of the risk for psychotic disorders among first- and second-generation immigrants. Psychological Medicine 41, 897910.
Bradley, AJ, Dinan, TG (2010). A systematic review of hypothalamic–pituitary–adrenal axis function in schizophrenia: implications for mortality. Journal of Psychopharmacology 24, 91118.
Bramon, E, McDonald, C, Croft, RJ, Landau, S, Filbey, F, Gruzelier, JH, Sham, PC, Frangou, S, Murray, RM (2005). Is the P300 wave an endophenotype for schizophrenia? A meta-analysis and a family study. Neuroimage 27, 960968.
Bramon, E, Rabe-Hesketh, S, Sham, P, Murray, RM, Frangou, S (2004). Meta-analysis of the P300 and P50 waveforms in schizophrenia. Schizophrenia Research 70, 315329.
Brugger, S, Davis, JM, Leucht, S, Stone, JM (2011). Proton magnetic resonance spectroscopy and illness stage in schizophreniaa systematic review and meta-analysis. Biological Psychiatry 69, 495503.
Button, KS, Ioannidis, JPA, Mokrysz, C, Nosek, BA, Flint, J, Robinson, ESJ, Munafò, MR (2013). Power failure: why small sample size undermines the reliability of neuroscience. Nature Reviews Neuroscience 14, 365378.
Calkins, ME, Iacono, WG, Ones, DS (2008). Eye movement dysfunction in first-degree relatives of patients with schizophrenia: a meta-analytic evaluation of candidate endophenotypes. Brain and Cognition 68, 436461.
Cannon, M, Jones, PB, Murray, RM (2002). Obstetric complications and schizophrenia: historical and meta-analytic review. American Journal of Psychiatry 159, 10801092.
Cantor-Graae, E, Selten, JP (2005). Schizophrenia and migration: a meta-analysis and review. American Journal of Psychiatry 162, 1224.
Catts, VS, Catts, SV, O'Toole, BI, Frost, AD, Frost, ADJ (2008). Cancer incidence in patients with schizophrenia and their first-degree relatives – a meta-analysis. Acta Psychiatrica Scandinavica 117, 323336.
Chakos, M, Lieberman, J, Hoffman, E, Bradford, D, Sheitman, B (2001). Effectiveness of second-generation antipsychotics in patients with treatment-resistant schizophrenia: a review and meta-analysis of randomized trials. American Journal of Psychiatry 158, 518526.
Chan, RCK, Di, X, McAlonan, GM, Gong, QY (2011). Brain anatomical abnormalities in high-risk individuals, first-episode, and chronic schizophrenia: an activation likelihood estimation meta-analysis of illness progression. Schizophrenia Bulletin 37, 177188.
Chan, RCK, Li, H, Cheung, EFC, Gong, Q-Y (2010 a). Impaired facial emotion perception in schizophrenia: a meta-analysis. Psychiatry Research 178, 381390.
Chan, RCK, Xu, T, Heinrichs, RW, Yu, Y, Gong, QY (2010 b). Neurological soft signs in non-psychotic first-degree relatives of patients with schizophrenia: a systematic review and meta-analysis. Neuroscience and Biobehavioral Reviews 34, 889896.
Chan, RCK, Xu, T, Heinrichs, RW, Yu, Y, Wang, Y (2010 c). Neurological soft signs in schizophrenia: a meta-analysis. Schizophrenia Bulletin 36, 10891104.
Chong, TW, Castle, DJ (2004). Layer upon layer: thermoregulation in schizophrenia. Schizophrenia Research 69, 149157.
Chouinard, S, Poulin, J, Stip, E, Godbout, R (2004). Sleep in untreated patients with schizophrenia: a meta-analysis. Schizophrenia Bulletin 30, 957967.
Chuma, J, Mahadun, P (2011). Predicting the development of schizophrenia in high-risk populations: systematic review of the predictive validity of prodromal criteria. British Journal of Psychiatry 199, 361366.
Cochrane Collaboration (2008). Cochrane Handbook for Systematic Reviews of Interventions. John Wiley and Sons: Chichester.
Cohen, AS, Brown, LA, Auster, TL (2012). Olfaction, “olfiction,” and the schizophrenia-spectrum: an updated meta-analysis on identification and acuity. Schizophrenia Research 135, 152157.
Cohen, AS, Minor, KS (2010). Emotional experience in patients with schizophrenia revisited: meta-analysis of laboratory studies. Schizophrenia Bulletin 36, 143150.
Cohen, J (1988). Statistical Power Analysis for the Behavioral Sciences, 2nd edn. Erlbaum: Hillsdale, NJ.
Copeland, LA, Zeber, JE, Pugh, MJ, Mortensen, EM, Restrepo, MI, Lawrence, VA (2008). Postoperative complications in the seriously mentally ill: a systematic review of the literature. Annals of Surgery 248, 3138.
Crossley, NA, Constante, M, McGuire, P, Power, P (2010). Efficacy of atypical v. typical antipsychotics in the treatment of early psychosis: meta-analysis. British Journal of Psychiatry 196, 434439.
Crowther, R, Marshall, M, Bond, G, Huxley, P (2001). Vocational rehabilitation for people with severe mental illness. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD003080. doi:10.1002/14651858.CD003080.
de Gracia Dominguez, M, Viechtbauer, W, Simons, CJ, van Os, J, Krabbendam, L (2009). Are psychotic psychopathology and neurocognition orthogonal? A systematic review of their associations. Psychological Bulletin 135, 157171.
de Leon, J, Diaz, FJ (2005). A meta-analysis of worldwide studies demonstrates an association between schizophrenia and tobacco smoking behaviors. Schizophrenia Research 76, 135157.
de Wilde, OM, Bour, LJ, Dingemans, PM, Koelman, JH, Linszen, DH, Koelman, JHTM (2007). A meta-analysis of P50 studies in patients with schizophrenia and relatives: differences in methodology between research groups. Schizophrenia Research 97, 137151.
Demeulemeester, M, Amad, A, Bubrovszky, M, Pins, D, Thomas, P, Jardri, R (2012). What is the real effect of 1-Hz repetitive transcranial magnetic stimulation on hallucinations? Controlling for publication bias in neuromodulation trials. Biological Psychiatry 71, e15e16.
Dibben, CR, Rice, C, Laws, K, McKenna, PJ (2009). Is executive impairment associated with schizophrenic syndromes? A meta-analysis. Psychological Medicine 39, 381392.
Dickinson, D, Ramsey, ME, Gold, JM (2007). Overlooking the obvious: a meta-analytic comparison of digit symbol coding tasks and other cognitive measures in schizophrenia. Archives of General Psychiatry 64, 532542.
Dickson, H, Laurens, KR, Cullen, AE, Hodgins, S (2012). Meta-analyses of cognitive and motor function in youth aged 16 years and younger who subsequently develop schizophrenia. Psychological Medicine 42, 743755.
Dieterich, M, Irving, CB, Park, B, Marshall, M (2010). Intensive case management for severe mental illness. Cochrane Database of Systematic Reviews, Issue 10. Art. No.: CD007906. doi:10.1002/14651858.CD007906.pub2.
Dlabac-de Lange, JJ, Knegtering, R, Aleman, A (2010). Repetitive transcranial magnetic stimulation for negative symptoms of schizophrenia: review and meta-analysis. Journal of Clinical Psychiatry 71, 411418.
Duggan, L, Fenton, M, Rathbone, J, Dardennes, R, El-Dosoky, A, Indran, S (2005). Olanzapine for schizophrenia. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD001359. doi:10.1002/14651858.CD001359.pub2.
Eack, SM, Newhill, CE (2007). Psychiatric symptoms and quality of life in schizophrenia: a meta-analysis. Schizophrenia Bulletin 33, 12251237.
Ellison-Wright, I, Bullmore, E (2009). Meta-analysis of diffusion tensor imaging studies in schizophrenia. Schizophrenia Research 108, 310.
Esterberg, M, Trotmana, HD, Holtzmana, C, Compton, MT, Walker, EF (2010). The impact of a family history of psychosis on age-at-onset and positive and negative symptoms of schizophrenia: a meta-analysis. Schizophrenia Research 120, 121130.
Farooq, S, Large, M, Nielssen, O, Waheed, W (2009). The relationship between the duration of untreated psychosis and outcome in low- and-middle income countries: a systematic review and meta analysis. Schizophrenia Research 109, 1523.
Fazel, S, Gulati, G, Linsell, L, Geddes, JR, Grann, M (2009). Schizophrenia and violence: systematic review and meta-analysis. PLoS Medicine 6, 120.
Fazel, S, Khosla, V, Doll, H, Geddes, J (2008). The prevalence of mental disorders among the homeless in western countries: systematic review and meta-regression analysis. PLoS Medicine 5, e225.
Fazel, S, Seewald, K (2012). Severe mental illness in 33 588 prisoners worldwide: systematic review and meta-regression analysis. British Journal of Psychiatry 200, 364373.
Fekadu, A, Shibre, T, Cleare, AJ (2010). Toxoplasmosis as a cause for behaviour disorders – overview of evidence and mechanisms. Folia Parasitologica 57, 105113.
Fenton, WS, Hibbeln, J, Knable, M (2000). Essential fatty acids, lipid membrane abnormalities, and the diagnosis and treatment of schizophrenia. Biological Psychiatry 47, 821.
Fett, AK, Viechtbauer, W, Dominguez, MD, Penn, DL, van Os, J, Krabbendam, L (2011). The relationship between neurocognition and social cognition with functional outcomes in schizophrenia: a meta-analysis. Neuroscience and Biobehavioral Reviews 35, 573588.
Folsom, D, Jeste, DV (2002). Schizophrenia in homeless persons: a systematic review of the literature. Acta Psychiatrica Scandinavica 105, 404413.
Forbes, NF, Carrick, LA, McIntosh, AM, Lawrie, SM (2009). Working memory in schizophrenia: a meta-analysis. Psychological Medicine 39, 889905.
Fusar-Poli, P, Bonoldi, I, Yung, AR, Borgwardt, S, Kempton, MJ, Valmaggia, L, Barale, F, Caverzasi, E, McGuire, P (2012 a). Predicting psychosis: meta-analysis of transition outcomes in individuals at high clinical risk. Archives of General Psychiatry 69, 220229.
Fusar-Poli, P, Deste, G, Smieskova, R, Barlati, S, Yung, AR, Howes, O, Stieglitz, RD, Vita, A, McGuire, P, Borgwardt, S (2012 b). Cognitive functioning in prodromal psychosis: a meta-analysis. Archives of General Psychiatry 69, 562571.
Fusar-Poli, P, Meyer-Lindenberg, A (2013 a). Striatal presynaptic dopamine in schizophrenia, part II: meta-analysis of [18F/11C]-DOPA PET studies. Schizophrenia Bulletin 39, 3342.
Fusar-Poli, P, Meyer-Lindenberg, A (2013 b). Striatal presynaptic dopamine in schizophrenia, part I: meta-analysis of dopamine active transporter (DAT) density. Schizophrenia Bulletin 39, 2232.
Fusar-Poli, P, Smieskova, R, Kempton, MJ, Ho, BC, Andreasen, NC, Borgwardt, S (2013). Progressive brain changes in schizophrenia related to antipsychotic treatment? A meta-analysis of longitudinal MRI studies. Neuroscience and Biobehavioral Reviews 37, 16801691.
Galderisi, S, Mucci, A, Volpe, U, Boutros, N (2009). Evidence-based medicine and electrophysiology in schizophrenia. Clinical EEG and Neuroscience 40, 6277.
Goghari, VM (2011). Executive functioning-related brain abnormalities associated with the genetic liability for schizophrenia: an activation likelihood estimation meta-analysis. Psychological Medicine 41, 12391252.
Gold, C, Solli, HP, Kruger, V, Lie, SA (2009). Dose–response relationship in music therapy for people with serious mental disorders: systematic review and meta-analysis. Clinical Psychology Review 29, 193207.
Golembo-Smith, S, Walder, DJ, Daly, MP, Mittal, VA, Kline, E, Reeves, G, Schiffman, J (2012). The presentation of dermatoglyphic abnormalities in schizophrenia: a meta-analytic review. Schizophrenia Research 142, 111.
GRADE Working Group (2004). Grading quality of evidence and strength of recommendations. BMJ (Clinical Research Edition) 328, 1490.
Green, MJ, Matheson, SL, Shepherd, A, Weickert, CS, Carr, VJ (2011). Brain-derived neurotrophic factor levels in schizophrenia: a systematic review with meta-analysis. Molecular Psychiatry 16, 960972.
Guyatt, G, Oxman, AD, Akl, EA, Kunz, R, Vist, G, Brozek, J, Norris, S, Falck-Ytter, Y, Glasziou, P, deBeer, H, Jaeschke, R, Rind, D, Meerpohl, J, Dahm, P, Schünemann, HJ (2011 a). GRADE guidelines: 1. Introduction – GRADE evidence profiles and summary of findings tables. Journal of Clinical Epidemiology 64, 383394.
Guyatt, GH, Oxman, AD, Kunz, R, Woodcock, J, Brozek, J, Helfand, M, Alonso-Coello, P, Glasziou, O, Jaeschke, R, Akl, EA, Norris, S, Vist, G, Dahm, P, Shukla, VK, Higgins, J, Falck-Ytter, Y, Schünemann, HJ; GRADE Working Group (2011 b). GRADE guidelines: 7. Rating the quality of evidence – inconsistency. Journal of Clinical Epidemiology 64, 12941302.
Guyatt, GH, Oxman, AD, Kunz, R, Brozek, J, Alonso-Coello, P, Rind, D, Devereaux, PJ, Montori, VM, Freyschuss, B, Vist, G, Jaeschke, R, Williams, JWJ, Murad, MH, Sinclair, D, Falck-Ytter, Y, Meerpohl, J, Whittington, C, Thorlund, K, Andrews, J, Schünemann, HJ (2011 c). GRADE guidelines: 6. Rating the quality of evidence – imprecision. Journal of Clinical Epidemiology 64, 12831293.
Guyatt, GH, Oxman, AD, Kunz, R, Woodcock, J, Brozek, J, Helfand, M, Alonso-Coello, P, Falck-Ytter, Y, Jaeschke, R, Vist, G, Akl, EA, Post, PN, Norris, S, Meerpohl, J, Shukla, VK, Nasser, M, Schünemann, HJ; GRADE Working Group (2011 d). GRADE guidelines: 8. Rating the quality of evidence – indirectness. Journal of Clinical Epidemiology 64, 13031310.
Haijma, SV, Van Haren, N, Cahn, W, Koolschijn, PCMP, Hulshoff Pol, HE, Kahn, RS (2013). Brain volumes in schizophrenia: a meta-analysis in over 18 000 subjects. Schizophrenia Bulletin 39, 11291138.
Harrison, PJ, Freemantle, N, Geddes, JR (2003). Meta-analysis of brain weight in schizophrenia. Schizophrenia Research 64, 2534.
Howes, O, Kambeitz, J, Kim, E, Stahl, D, Slifstein, M, Abi-Dargham, A, Kapur, S (2012). The nature of dopamine dysfunction in schizophrenia and what this means for treatment: meta-analysis of imaging studies. Archives of General Psychiatry 69, 776786.
Ioannidis, JPA (2005). Why most published research findings are false. PLoS Medicine 2, e124.
Irani, F, Seligman, S, Kamath, V, Kohler, C, Gur, RC (2012). A meta-analysis of emotion perception and functional outcomes in schizophrenia. Schizophrenia Research 137, 203211.
Irving, CB, Adams, CE, Lawrie, SM (2006). Haloperidol versus placebo for schizophrenia. Cochrane Database of Systematic Reviews, Issue 4. Art. No.: CD003082. doi:10.1002/14651858.CD003082.pub2.
Jardri, R, Pouchet, A, Pins, D, Thomas, P (2011). Cortical activations during auditory verbal hallucinations in schizophrenia: a coordinate-based meta-analysis. American Journal of Psychiatry 168, 7381.
Johnson-Selfridge, M, Zalewski, C (2001). Moderator variables of executive functioning in schizophrenia: meta-analytic findings. Schizophrenia Bulletin 27, 305316.
Jones, C, Hacker, D, Cormac, I, Meaden, A, Irving, CB (2012). Cognitive behaviour therapy versus other psychosocial treatments for schizophrenia. Cochrane Database of Systematic Reviews, Issue 4. Art. No.: CD008712. doi:10.1002/14651858.CD008712.pub2.
Kempton, M, Stahl, D, Williams, SCR, DeLisi, LE (2010). Progressive lateral ventricular enlargement in schizophrenia: a meta-analysis of longitudinal MRI studies. Schizophrenia Research 120, 5462.
Keshavan, MS, Tandon, R, Boutros, NN, Nasrallah, HA (2008). Schizophrenia, part 3 – Just the Facts. What we know in 2008: neurobiology. Schizophrenia Research 106, 89107.
Khandaker, GM, Barnett, JH, White, IR, Jones, PB (2011). A quantitative meta-analysis of population-based studies of premorbid intelligence and schizophrenia. Schizophrenia Research 132, 220227.
Khandaker, GM, Zimbron, J, Dalman, C, Lewis, G, Jones, PB (2012). Childhood infection and adult schizophrenia: a meta-analysis of population-based studies. Schizophrenia Research 139, 161168.
Khandaker, GM, Zimbron, J, Lewis, G, Jones, PB (2013). Prenatal maternal infection, neurodevelopment and adult schizophrenia: a systematic review of population based studies. Psychological Medicine 43, 239257.
Kinney, DK, Teixeira, P, Hsu, D, Napoleon, SC, Crowley, DJ, Miller, A, Hyman, W, Huang, E (2009). Relation of schizophrenia prevalence to latitude, climate, fish consumption, infant mortality, and skin color: a role for prenatal vitamin D deficiency and infections? Schizophrenia Bulletin 35, 582595.
Kirkbride, JB, Errazuriz, A, Croudace, TJ, Morgan, C, Jackson, D, Boydell, J, Murray, RM, Jones, PB (2012). Incidence of schizophrenia and other psychoses in England, 1950–2009: a systematic review and meta-analyses. PLOS ONE 7, e31660.
Knowles, EEM, David, AS, Reichenberg, A (2010). Processing speed deficits in schizophrenia: reexamining the evidence. American Journal of Psychiatry 167, 828835.
Kohler, C, Walker, J, Martin, E, Healey, K, Moberg, P (2010). Facial emotion perception in schizophrenia: a meta-analytic review. Schizophrenia Bulletin 36, 10091019.
Kompus, K, Westerhausen, R, Hugdahl, K (2011). The “paradoxical” engagement of the primary auditory cortex in patients with auditory verbal hallucinations: a meta-analysis of functional neuroimaging studies. Neuropsychologia 49, 33613369.
Koskinen, J, Lohonen, J, Koponen, H, Isohanni, M, Miettunen, J (2010). Rate of cannabis use disorders in clinical samples of patients with schizophrenia: a meta-analysis. Schizophrenia Bulletin 36, 11151130.
Krabbendam, L, Arts, B, van Os, J, Aleman, A (2005). Cognitive functioning in patients with schizophrenia and bipolar disorder: a quantitative review. Schizophrenia Research 80, 137149.
Kraguljac, NV, Reid, M, White, D, Jones, R, den Hollander, J, Lowman, D, Lahti, AC (2012). Neurometabolites in schizophrenia and bipolar disorder – a systematic review and meta-analysis. Psychiatry Research 203, 111125.
Kuhn, S, Gallinat, J (2012). Quantitative meta-analysis on state and trait aspects of auditory verbal hallucinations in schizophrenia. Schizophrenia Bulletin 38, 779786.
Kurtz, MM, Mueser, KT (2008). A meta-analysis of controlled research on social skills training for schizophrenia. Journal of Consulting and Clinical Psychology 76, 491504.
Kurtz, MM, Richardson, CL (2012). Social cognitive training for schizophrenia: a meta-analytic investigation of controlled research. Schizophrenia Bulletin 38, 10921104.
Kuswanto, CN, Teh, I, Lee, TS, Sim, K (2012). Diffusion tensor imaging findings of white matter changes in first episode schizophrenia: a systematic review. Clinical Psychopharmacology and Neuroscience 10, 1324.
Large, M, Nielssen, O (2008). Evidence for a relationship between the duration of untreated psychosis and the proportion of psychotic homicides prior to treatment. Social Psychiatry and Psychiatric Epidemiology 43, 3744.
Large, M, Sharma, S, Compton, MT, Slade, T, Nielssen, O (2011 a). Cannabis use and earlier onset of psychosis: a systematic meta-analysis. Archives of General Psychiatry 68, 555561.
Large, M, Smith, G, Sharma, S, Nielssen, O, Singh, SP (2011 b). Systematic review and meta-analysis of the clinical factors associated with the suicide of psychiatric in-patients. Acta Psychiatrica Scandinavica 124, 1819.
Large, MM, Nielssen, O, Ryan, CJ, Hayes, R (2008). Mental health laws that require dangerousness for involuntary admission may delay the initial treatment of schizophrenia. Social Psychiatry and Psychiatric Epidemiology 43, 251256.
Leucht, S, Kissling, W, McGrath, J (2007 a). Lithium for schizophrenia. Cochrane Database of Systematic Reviews, Issue 3. Art. No.: CD003834. doi:10.1002/14651858.CD003834.
Leucht, S, Burkard, T, Henderson, J, Maj, M, Sartorius, N (2007 b). Physical illness and schizophrenia: a review of the literature. Acta Psychiatrica Scandinavica 116, 317333.
Leucht, S, Lasser, R (2006). The concepts of remission and recovery in schizophrenia. Pharmacopsychiatry 39, 161170.
Leucht, S, Tardy, M, Komossa, K, Heres, S, Kissling, W, Davis, JM (2012 a). Maintenance treatment with antipsychotic drugs for schizophrenia. Cochrane Database of Systematic Reviews, Issue 5. Art. No.: CD008016. doi:10.1002/14651858.CD008016.pub2.
Leucht, S, Tardy, M, Komossa, K, Heres, S, Kissling, W, Salanti, G, Davis, JM (2012 b). Antipsychotic drugs versus placebo for relapse prevention in schizophrenia: a systematic review and meta-analysis. Lancet 379, 20632071.
Li, H, Chan, R, McAlonan, G, Gong, Q (2010). Facial emotion processing in schizophrenia: a meta-analysis of functional neuroimaging data. Schizophrenia Bulletin 36, 10291039.
Livingston, JD, Boyd, JE (2010). Correlates and consequences of internalized stigma for people living with mental illness: a systematic review and meta-analysis. Social Science and Medicine 71, 21502161.
Llerena, K, Strauss, GP, Cohen, AS (2012). Looking at the other side of the coin: a meta-analysis of self-reported emotional arousal in people with schizophrenia. Schizophrenia Research 142, 6570.
MacDonald, AW, Schulz, SC (2009). What we know: findings that every theory of schizophrenia should explain. Schizophrenia Bulletin 35, 493508.
MacDonald, AW 3rd, Thermenos, HW, Barch, DM, Seidman, LJ (2009). Imaging genetic liability to schizophrenia: systematic review of FMRI studies of patients’ nonpsychotic relatives. Schizophrenia Bulletin 35, 11421162.
Maniglio, R (2009). Severe mental illness and criminal victimization: a systematic review. Acta Psychiatrica Scandinavica 119, 180191.
Marshall, M, Lewis, S, Lockwood, A, Drake, R, Jones, P, Croudace, T (2005). Association between duration of untreated psychosis and outcome in cohorts of first-episode patients: a systematic review. Archives of General Psychiatry 62, 975983.
Marsman, A, Van Den Heuvel, MP, Klomp, DWJ, Kahn, RS, Luijten, PR, Hulshoff Pol, HE (2013). Glutamate in schizophrenia: a focused review and meta-analysis of 1H-MRS studies. Schizophrenia Bulletin 39, 120129.
Matheson, SL, Shepherd, AM, Pinchbeck, RM, Laurens, KR, Carr, VJ (2012). Childhood adversity in schizophrenia: a systematic meta-analysis. Psychological Medicine 43, 225238.
McGrath, J, Saha, S, Welham, J, El Saadi, O, MacCauley, C, Chant, D (2004). A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology. BMC Medicine 2, 13.
McGurk, SR, Twamley, EW, Sitzer, DI, McHugo, GJ, Mueser, KT (2007). A meta-analysis of cognitive remediation in schizophrenia. American Journal of Psychiatry 164, 17911802.
Menezes, NM, Arenovich, T, Zipursky, RB (2006). A systematic review of longitudinal outcome studies of first-episode psychosis. Psychological Medicine 36, 13491362.
Mesholam-Gately, RI, Giuliano, AJ, Goff, KP, Faraone, SV, Seidman, LJ (2009). Neurocognition in first-episode schizophrenia: a meta-analytic review. Neuropsychology 23, 315336.
Meyer, JM, Stahl, SM (2009). The metabolic syndrome and schizophrenia. Acta Psychiatrica Scandinavica 119, 414.
Miller, B, Messias, E, Miettunen, J, Alaraisanen, A, Jarvelin, MR, Koponen, H, Rasanen, P, Isohanni, M, Kirkpatrick, B (2011). Meta-analysis of paternal age and schizophrenia risk in male versus female offspring. Schizophrenia Bulletin 37, 10391047.
Miller, BJ, Buckley, P, Seabolt, W, Mellor, A, Kirkpatrick, B (2011). Meta-analysis of cytokine alterations in schizophrenia: clinical status and antipsychotic effects. Biological Psychiatry 70, 663671.
Mintz, AR, Dobson, KS, Romney, DM (2003). Insight in schizophrenia: a meta-analysis. Schizophrenia Research 61, 7588.
Minzenberg, MJ, Laird, AR, Thelen, S, Carter, CS, Glahn, DC (2009). Meta-analysis of 41 functional neuroimaging studies of executive function in schizophrenia. Archives of General Psychiatry 66, 811822.
Moher, D, Liberati, A, Tetzlaff, J, Altman, DG; PRISMA Group (2009). Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. BMJ (Clinical Research Ed) 151, 264269.
Molloy, C, Conroy, RM, Cotter, DR, Cannon, M (2011). Is traumatic brain injury a risk factor for schizophrenia? A meta-analysis of case-controlled population-based studies. Schizophrenia Bulletin 37, 11041110.
Moncrieff, J (2003). Clozapine v. conventional antipsychotic drugs for treatment-resistant schizophrenia: a re-examination. British Journal of Psychiatry 183, 161166.
Moore, TH, Zammit, S, Lingford-Hughes, A, Barnes, TR, Jones, PB, Burke, M, Lewis, G (2007). Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet 370, 319328.
Mössler, K, Chen, X, Heldal, TO, Gold, C (2011). Music therapy for people with schizophrenia and schizophrenia-like disorders. Cochrane Database of Systematic Reviews, Issue 12. Art. No.: CD004025. doi:10.1002/14651858.CD004025.pub3.
Mota, NE, Lima, MS, Soares, BG (2002). Amisulpride for schizophrenia. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD001357. doi:10.1002/14651858.CD001357.
Murphy, S, Irving, CB, Adams, CE, Driver, R (2012). Crisis intervention for people with severe mental illnesses. Cochrane Database of Systematic Reviews, Issue 5. Art. No.: CD001087. doi:10.1002/14651858.CD001087.pub4.
Newton-Howes, G, Tyrer, P, North, B, Yang, M (2008). The prevalence of personality disorder in schizophrenia and psychotic disorders: systematic review of rates and explanatory modelling. Psychological Medicine 38, 10751082.
Nieuwenstein, MR, Aleman, A, de Haan, EH (2001). Relationship between symptom dimensions and neurocognitive functioning in schizophrenia: a meta-analysis of WCST and CPT studies. Wisconsin Card Sorting Test. Continuous performance test. Journal of Psychiatric Research 35, 119125.
Nussbaum, AM, Stroup, TS (2008). Oral paliperidone for schizophrenia. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD006369. doi:10.1002/14651858.CD006369.pub2.
O'Driscoll, GA, Callahan, BL (2008). Smooth pursuit in schizophrenia: a meta-analytic review of research since 1993. Brain and Cognition 68, 359370.
Olabi, B, Ellison-Wright, I, McIntosh, AM, Wood, SJ, Bullmore, E, Lawrie, SM (2011). Are there progressive brain changes in schizophrenia? A meta-analysis of structural magnetic resonance imaging studies. Biological Psychiatry 70, 8896.
Osborn, DP, Wright, CA, Levy, G, King, MB, Deo, R, Nazareth, I (2008). Relative risk of diabetes, dyslipidaemia, hypertension and the metabolic syndrome in people with severe mental illnesses: systematic review and metaanalysis. BMC Psychiatry 8, 84.
Oud, MJ, Meyboom-De Jong, B (2009). Somatic diseases in patients with schizophrenia in general practice: their prevalence and health care. BMC Family Practice 10, 32.
Palaniyappan, L, Balain, V, Liddle, PF (2012). The neuroanatomy of psychotic diathesis: a meta-analytic review. Journal of Psychiatric Research 46, 12491256.
Palmer, BA, Pankratz, VS, Bostwick, JM (2005). The lifetime risk of suicide in schizophrenia: a reexamination. Archives of General Psychiatry 62, 247253.
Patel, S, Mahon, K, Wellington, R, Zhang, J, Chaplin, W, Szeszko, PR (2011). A meta-analysis of diffusion tensor imaging studies of the corpus callosum in schizophrenia. Schizophrenia Research 129, 149155.
Pelletier, M, Achim, AM, Montoya, A, Lal, S, Lepage, M (2005). Cognitive and clinical moderators of recognition memory in schizophrenia: a meta-analysis. Schizophrenia Research 74, 233252.
Pfammatter, M, Junghan, UM, Brenner, HD (2006). Efficacy of psychological therapy in schizophrenia: conclusions from meta-analyses. Schizophrenia Bulletin 32, S64S80.
Pharoah, F, Mari, J, Rathbone, J, Wong, W (2010). Family intervention for schizophrenia. Cochrane Database of Systematic Reviews, Issue 4. Art. No.: CD000088. doi:10.1002/14651858.CD000088.pub2.
Potvin, S, Blanche, P, Stip, E (2009). Substance abuse is associated with increased extrapyramidal symptoms in schizophrenia: a meta-analysis. Schizophrenia Research 113, 181188.
Potvin, S, Marchand, S (2008). Hypoalgesia in schizophrenia is independent of antipsychotic drugs: a systematic quantitative review of experimental studies. Pain 138, 7078.
Potvin, S, Sepehry, AA, Stip, E (2006). A meta-analysis of negative symptoms in dual diagnosis schizophrenia. Psychological Medicine 36, 431440.
Preti, A, Cella, M (2010). Randomized-controlled trials in people at ultra high risk of psychosis: a review of treatment effectiveness. Schizophrenia Research 123, 3036.
Ragland, JD, Laird, AR, Ranganath, C, Blumenfeld, RS, Gonzales, SM, Glahn, DC (2009). Prefrontal activation deficits during episodic memory in schizophrenia. American Journal of Psychiatry 166, 863874.
Rajji, TK, Ismail, Z, Mulsant, BH (2009). Age at onset and cognition in schizophrenia: meta-analysis. British Journal of Psychiatry 195, 286293.
Rattehalli, RD, Jayaram, MB, Smith, M (2010). Risperidone versus placebo for schizophrenia. Cochrane Database of Systematic Reviews, Issue 1. Art. No.: CD006918. doi:10.1002/14651858.CD006918.pub2.
Read, J, Haslam, N, Sayce, L, Davies, E (2006). Prejudice and schizophrenia: a review of the ‘mental illness is an illness like any other’ approach. Acta Psychiatrica Scandinavica 114, 303318.
Rietkerk, T, Boks, MP, Sommer, IE, Liddle, PF, Ophoff, RA, Kahn, RS, Boks, MPM (2008). The genetics of symptom dimensions of schizophrenia: review and meta-analysis. Schizophrenia Research 102, 197205.
Roder, V, Mueller, DR, Schmidt, SJ (2011). Effectiveness of integrated psychological therapy (IPT) for schizophrenia patients: a research update. Schizophrenia Bulletin 37, S71S79.
Rosenthal, JA (1996). Qualitative descriptors of strength of association and effect size. Journal of Social Service Research 21, 3758.
Rubio, JM, Sanjuán, J, Flórez-Salamanca, L, Cuesta, MJ (2012). Examining the course of hallucinatory experiences in children and adolescents: a systematic review. Schizophrenia Research 138, 248254.
Saha, S, Chant, D, McGrath, J (2007). A systematic review of mortality in schizophrenia: is the differential mortality gap worsening over time? Archives of General Psychiatry 64, 11231131.
Saha, S, Chant, D, Welham, J, McGrath, J (2005). A systematic review of the prevalence of schizophrenia. PLoS Medicine 2, e141.
Sarin, F, Wallin, L, Widerlov, B (2011). Cognitive behavior therapy for schizophrenia: a meta-analytical review of randomized controlled trials. Nordic Journal of Psychiatry 65, 162174.
Savla, GN, Vella, L, Armstrong, CC, Penn, DL, Twamley, EW (2012). Deficits in domains of social cognition in schizophrenia: a meta-analysis of the empirical evidence. Schizophrenia Bulletin. Published online 4 September 2012 . doi:10.1093/schbul/sbs1080.
Schmidt, SJ, Mueller, DR, Roder, V (2011). Social cognition as a mediator variable between neurocognition and functional outcome in schizophrenia: empirical review and new results by structural equation modeling. Schizophrenia Bulletin 37, S41S54.
Schroeter, ML, Abdul-Khaliq, H, Krebs, M, Diefenbacher, A, Blasig, IE (2009). Neuron-specific enolase is unaltered whereas S100B is elevated in serum of patients with schizophrenia – original research and meta-analysis. Psychiatry Research 167, 6672.
Schultz, PW, Searleman, A (2002). Rigidity of thought and behavior: 100 years of research. Genetic, Social, and General Psychology Monographs 128, 165207.
Shepherd, AM, Matheson, SL, Laurens, KR, Carr, VJ, Green, MJ (2012). Systematic meta-analysis of insula volume in schizophrenia. Biological Psychiatry 72, 775784.
Singh, SP, Singh, V (2011). Meta-analysis of the efficacy of adjunctive NMDA receptor modulators in chronic schizophrenia. CNS Drugs 5, 859885.
Singh, V, Singh, SP, Chan, K (2010 a). Review and meta-analysis of usage of ginkgo as an adjunct therapy in chronic schizophrenia. International Journal of Neuropsychopharmacology 13, 257271.
Singh, S, Singh, V, Kar, N, Chan, K (2010 b). Efficacy of antidepressants in treating the negative symptoms of chronic schizophrenia: meta-analysis. British Journal of Psychiatry 197, 174179.
Sitskoorn, MM, Aleman, A, Ebisch, SJ, Appels, MC, Kahn, RS (2004). Cognitive deficits in relatives of patients with schizophrenia: a meta-analysis. Schizophrenia Research 71, 285295.
Slotema, CW, Aleman, A, Daskalakis, ZJ, Sommer, IE (2012). Meta-analysis of repetitive transcranial magnetic stimulation in the treatment of auditory verbal hallucinations: update and effects after one month. Schizophrenia Research 142, 4045.
Snitz, BE, Macdonald, AW 3rd, Carter, CS (2006). Cognitive deficits in unaffected first-degree relatives of schizophrenia patients: a meta-analytic review of putative endophenotypes. Schizophrenia Bulletin 32, 179194.
Sommer, I, Ramsey, N, Kahn, R, Aleman, A, Bouma, A (2001). Handedness, language lateralisation and anatomical asymmetry in schizophrenia: meta-analysis. British Journal of Psychiatry 178, 344351.
Sommer, IE, de Witte, L, Begemann, M, Kahn, RS (2012). Nonsteroidal anti-inflammatory drugs in schizophrenia: ready for practice or a good start? A meta-analysis. Journal of Clinical Psychiatry 73, 414419.
Sprong, M, Schothorst, P, Vos, E, Hox, J, van Engeland, H (2007). Theory of mind in schizophrenia: meta-analysis. British Journal of Psychiatry 191, 513.
Stefanopoulou, E, Manoharan, A, Landau, S, Geddes, JR, Goodwin, G, Frangou, S (2009). Cognitive functioning in patients with affective disorders and schizophrenia: a meta-analysis. International Review of Psychiatry 21, 336356.
Su, L, Cai, Y, Wang, L, Shi, S (2012). Various effects of antipsychotics on P50 sensory gating in Chinese schizophrenia patients: a meta-analysis. Psychiatria Danubina 24, 4450.
Sullivan, PF, Kendler, KS, Neale, MC (2003). Schizophrenia as a complex trait: evidence from a meta-analysis of twin studies. Archives of General Psychiatry 60, 11871192.
Szoke, A, Schurhoff, F, Mathieu, F, Meary, A, Ionescu, S, Leboyer, M (2005). Tests of executive functions in first-degree relatives of schizophrenic patients: a meta-analysis. Psychological Medicine 35, 771782.
Tandon, R, Keshavan, MS, Nasrallah, HA (2008 a). Schizophrenia, part 1 – Just the Facts. What we know in 2008: an overview. Schizophrenia Research 100, 419.
Tandon, R, Keshavan, MS, Nasrallah, HA (2008 b). Schizophrenia, part 2 – Just the Facts. What we know in 2008. Epidemiology and etiology. Schizophrenia Research 102, 118.
Tandon, R, Nasrallah, HA, Keshavan, MS (2009). Schizophrenia, part 4 – Just the Facts. Clinical features and conceptualization. Schizophrenia Research 110, 123.
Tandon, R, Nasrallah, HA, Keshavan, MS (2010). Schizophrenia, ‘Just the Facts’: 5. Treatment and prevention. Past, present, and future. Schizophrenia Research 122, 123.
Tarbox, SI, Pogue-Geile, MF (2008). Development of social functioning in preschizophrenia children and adolescents: a systematic review. Psychological Bulletin 134, 561583.
Taylor, SF, Kang, J, Brege, IS, Tso, IF, Hosanagar, A, Johnson, TD (2012). Meta-analysis of functional neuroimaging studies of emotion perception and experience in schizophrenia. Biological Psychiatry 71, 136145.
Tharyan, P, Adams, CE (2005). Electroconvulsive therapy for schizophrenia. Cochrane Database of Systematic Reviews, Issue 2. Art. No.: CD000076. doi:10.1002/14651858.CD000076.pub2.
Torrey, EF, Bartko, JJ, Yolken, RH (2012). Toxoplasma gondii and other risk factors for schizophrenia: an update. Schizophrenia Bulletin 38, 642647.
Trandafir, A, Meary, A, Schurhoff, F, Leboyer, M, Szoke, A (2006). Memory tests in first-degree adult relatives of schizophrenic patients: a meta-analysis. Schizophrenia Research 81, 217226.
Trzesniak, C, de Oliveira, IR, Kempton, MJ, Galvão-de Almeida, A, Chagas, MHN, Ferrari, MCF, Filho, AS, Zuardi, AW, Prado, DA, Busatto, GF, McGuire, PK, Hallak, JEC, Crippa, JAS (2011 a). Are cavum septum pellucidum abnormalities more common in schizophrenia spectrum disorders? A systematic review and meta-analysis. Schizophrenia Research 125, 112.
Trzesniak, C, Kempton, MJ, Busatto, GF, de Oliveira, IR, Galvao-de Almeida, A, Kambeitz, J, Ferrari, MCF, Santos, A, Chagas, MHN, Zuardi, AW, Hallak, JEC, McGuire, PK, Crippa, JAS (2011 b). Adhesio interthalamica alterations in schizophrenia spectrum disorders: a systematic review and meta-analysis. Progress in Neuro-Psychopharmacology and Biological Psychiatry 35, 877886.
Umbricht, D, Krljes, S (2005). Mismatch negativity in schizophrenia: a meta-analysis. Schizophrenia Research 76, 123.
van der Kemp, WJM, Klomp, DWJ, Kahn, RS, Luijten, PR, Hulshoff Pol, HE (2012). A meta-analysis of the polyunsaturated fatty acid composition of erythrocyte membranes in schizophrenia. Schizophrenia Research 141, 153161.
Van Snellenberg, JX, Torres, IJ, Thornton, AE (2006). Functional neuroimaging of working memory in schizophrenia: task performance as a moderating variable. Neuropsychology 20, 497510.
Vassos, E, Pedersen, CB, Murray, RM, Collier, DA, Lewis, CM (2012). Meta-analysis of the association of urbanicity with schizophrenia. Schizophrenia Bulletin 38, 11181123.
Ventura, J, Thames, AD, Wood, RC, Guzik, LH, Hellman, GS (2010). Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits. Schizophrenia Research 121, 114.
Ventura, J, Wood, RC, Hellemann, GS (2013). Symptom domains and neurocognitive functioning can help differentiate social cognitive processes in schizophrenia: a meta-analysis. Schizophrenia Bulletin 39, 102111.
Wang, K, Cheung, EFC, Gong, QY, Chan, RCK (2011). Semantic processing disturbance in patients with schizophrenia: a meta-analysis of the N400 component. PLoS ONE 6, e25435.
Wang, Y, Cui, J, Chan, RCK, Deng, Y, Shi, H, Hong, X, Li, Z, Yu, X, Gong, Q-Y, Shum, D (2009). Meta-analysis of prospective memory in schizophrenia: nature, extent, and correlates. Schizophrenia Research 114, 6470.
Waters, F, Woodward, T, Allen, P, Aleman, A, Sommer, I (2012). Self-recognition deficits in schizophrenia patients with auditory hallucinations: a meta-analysis of the literature. Schizophrenia Bulletin 38, 741750.
Weinberg, SM, Jenkins, EA, Marazita, ML, Maher, BS (2007). Minor physical anomalies in schizophrenia: a meta-analysis. Schizophrenia Research 89, 7285.
Welham, J, Isohanni, M, Jones, P, McGrath, J (2009). The antecedents of schizophrenia: a review of birth cohort studies. Schizophrenia Bulletin 35, 603623.
Whyte, MC, McIntosh, AM, Johnstone, EC, Lawrie, SM (2005). Declarative memory in unaffected adult relatives of patients with schizophrenia: a systematic review and meta-analysis. Schizophrenia Research 78, 1326.
Woodberry, KA, Giuliano, AJ, Seidman, LJ (2008). Premorbid IQ in schizophrenia: a meta-analytic review. American Journal of Psychiatry 165, 579587.
Woodward, ND, Purdon, SE, Meltzer, HY, Zald, DH (2005). A meta-analysis of neuropsychological change to clozapine, olanzapine, quetiapine, and risperidone in schizophrenia. International Journal of Neuropsychopharmacology 8, 457472.
Wright, IC, Rabe-Hesketh, S, Woodruff, PW, David, AS, Murray, RM, Bullmore, ET (2000). Meta-analysis of regional brain volumes in schizophrenia. American Journal of Psychiatry 157, 1625.
Xia, J, Merinder, LB, Belgamwar, MR (2011). Psychoeducation for schizophrenia. [update of Cochrane Database Syst Rev. 2002;(2):CD002831]. Cochrane Database of Systematic Reviews, Issue 6. Art. No.: CD002831. doi:10.1002/14651858.CD002831.pub2.
Xu, T, Chan, RCK, Compton, MT (2011). Minor physical anomalies in patients with schizophrenia, unaffected first-degree relatives, and healthy controls: a meta-analysis. PLoS ONE 6, e24129.
Yucel, M, Bora, E, Lubman, DI, Solowij, N, Brewer, WJ, Cotton, SM, Conus, P, Takagi, MJ, Fornito, A, Wood, SJ, McGorry, PD, Pantelis, C (2012). The impact of cannabis use on cognitive functioning in patients with schizophrenia: a meta-analysis of existing findings and new data in a first-episode sample. Schizophrenia Bulletin 38, 316330.

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