*Indicates studies included in the systematic review
1Beaudreau, SA, O’Hara, R. The association of anxiety and depressive symptoms with cognitive performance in community-dwelling older adults. Psychol Aging 2009; 24: 507–12.
2Beaudreau, SA, O’Hara, R. Late-life anxiety and cognitive impairment: a review. Am J Geriatric Psychiatry 2008; 16: 790–803.
3Diniz, BS, Butters, MA, Albert, SM, Dew, MA, Reynolds, CF. Late-life depression and risk of vascular dementia and Alzheimer's disease: systematic review and meta-analysis of community-based cohort studies. Br J Psychiatry 2013; 20: 329–35.
4Reppermund, S, Brodaty, H, Crawford, JD, Kochan, NA, Slavin, MJ, Trollor, JNet al.The relationship of current depressive symptoms and past depression with cognitive impairment and instrumental activities of daily living in an elderly population: the Sydney Memory and Ageing Study. J Psychiatr Res 2011; 45: 1600–7.
5Steffens, DC, McQuoid, DR, Potter, GG. Amnestic mild cognitive impairment and incident dementia and Alzheimer's disease in geriatric depression. Int Psychogeriatr 2014; 26: 2029–36.
6Yates, JA, Clare, L, Woods, RT. Mild cognitive impairment and mood: a systematic review. Rev Clin Gerontology 2013; 23: 217–56.
7Becker, JT, Chang, Y, Lopez, OL, Dew, MA, Sweet, RA, Barnes, Det al.Depressed mood is not a risk factor for incident dementia in a community-based cohort. Am J Geriatr Psychiatry 2009; 8: 653–63.
8de Bruijn, RFAG, Direk, N, Mirza, SS, Hofman, A, Koudstaal, PJ, Tiemeier, Het al.Anxiety is not associated with the risk of dementia or cognitive decline: the Rotterdam study. Am J Geriatr Psychiatry 2014; 22: 1382–90.
9Kindermann, SS, Brown, GG. Depression and memory in the elderly: a meta-analysis. J Clin Exp Neuropsychol 1997; 19: 625–42.
10Mortimer, JA, Snowdon, DA, Markesbery, WR. Head circumference, education and risk of dementia: findings from the Nun Study. J Clin Exp Neuropsychol 2003; 25: 671–79.
11Opdebeeck, C, Martyr, A, Clare, L. Cognitive reserve and cognitive function in healthy older people: a meta-analysis. Aging Neuropsychol Cogn 2015 (1 May: Epub ahead of print).
12Valenzuela, MJ, Sachdev, P. Brain reserve and dementia: a systematic review. Psychol Med 2006; 36: 441–54.
13Valenzuela, MJ, Sachdev, P. Brain reserve and cognitive decline: a non-parametric systematic review. Psychol Med 2006; 36: 1065–74.
14Benedict, RHB, Morrow, SA, Weinstock Guttman, B, Cookfair, D, Schretlen, DJ. Cognitive reserve moderates decline in information processing speed in multiple sclerosis patients. J Int Neuropsychol Soc 2010; 16: 829–35.
15Foley, JM, Ettenhofer, ML, Kim, MS, Behdin, N, Castellon, SA, Hinkin, CH. Cognitive reserve as a protective factor in older HIV-positive patients at risk for cognitive decline. Appl Neuropsychol 2012; 19: 16–25.
16Hindle, JV, Martyr, A, Clare, L. Cognitive reserve in Parkinson's disease: a systematic review and meta-analysis. Parkinsonism Relat Disord 2014; 20: 1–7.
17Kesler, SR, Adams, HF, Blasey, CM, Bigler, ED. Premorbid intellectual functioning, education, and brain size in traumatic brain injury: an investigation of the cognitive reserve hypothesis. Appl Neuropsychol 2003; 10: 153–62.
18Adams, KB, Leibbrandt, S, Moon, H. A critical review of the literature on social and leisure activity and wellbeing in later life. Ageing Society 2011; 31: 683–712.
19Bjelland, I, Krokstad, S, Mykletun, A, Dahl, AA, Tell, GS, Tambs, K. Does a higher educational level protect against anxiety and depression? The HUNT study. Soc Sci Med 2008; 66: 1334–45.
20Glass, TA, De Leon, CFM, Bassuk, SS, Berkman, LF. Social engagement and depressive symptoms in late life: longitudinal findings. J Aging Health 2006; 18: 604–28.
21Hong, S, Hasche, L, Bowland, S. Structural relationships between social activities and longitudinal trajectories of depression among older adults. Gerontologist 2009; 49: 1–11.
22Jenkins, A. Participation in learning and wellbeing among older adults. Int J Lifelong Education 2011; 30: 403–20.
23Ladin, K. Risk of late-life depression across 10 European Union countries: deconstructing the education effect. J Aging Health 2008; 20: 653–70.
24Lorant, V, Deliège, D, Eaton, W, Robert, A, Philippot, P, Ansseau, M. Socioeconomic inequalities in depression: a meta-analysis. Am J Epidemiol 2003; 157: 98–112.
25Murrell, SA, Salsman, NL, Meeks, S. Educational attainment, positive psychological mediators, and resources for health and vitality in older adults. J Aging Health 2003; 15: 591–615.
26Narushima, M, Liu, J, Diestelkamp, N. The association between lifelong learning and psychological well-being among older adults: implications for interdisciplinary health promotion in an aging society. Act Adapt Aging 2013; 37: 239–50.
27Ross, CE, Mirowsky, J. Sex differences in the effect of education on depression: resource multiplication or resource substitution? Soc Sci Med 2006; 63: 1400–13.
28Ross, CE, Mirowsky, J. Gender and the health benefits of education. Sociological Quarterly 2010; 51: 1–19.
29Ballmaier, M, Toga, AW, Blanton, RE, Sowell, ER, Lavretsky, H, Peterson, Jet al.Anterior cingulate, gyrus rectus, and orbitofrontal abnormalities in elderly depressed patients: an MRI-based parcellation of the prefrontal cortex. Am J Psychiatry 2004; 161: 99–108.
30Elbejjani, M, Fuhrer, R, Abrahamowicz, M, Mazoyer, B, Crivello, F, Tzourio, Cet al.Depression, depressive symptoms, and rate of hippocampal atrophy in a longitudinal cohort of older men and women. Psychol Med 2015; 15: 1931–44.
31Lampe, IK, Pol, HEH, Janssen, J, Schnack, HG, Kahn, RS, Heeren, TJ. Association of depression duration with reduction of global cerebral gray matter volume in female patients with recurrent major depressive disorder. Am J Psychiatry 2003; 160: 2052–54.
32Sandu, A, Staff, RT, McNeil, CJ, Mustafa, N, Ahearn, T, Whalley, LJet al.Structural brain complexity and cognitive decline in late life – a longitudinal study in the Aberdeen 1936 Birth Cohort. Neuroimage 2014; 100: 558–63.
33Byers, AL, Yaffe, K. Depression and risk of developing dementia. Nat Rev Neurol 2011; 7: 323–31.
34Korczyn, AD, Halperin, I. Depression and dementia. J Neurol Sci 2009; 283: 139–42.
35Leonard, BE. Inflammation, depression and dementia: are they connected? Neurochem Res 2007; 32: 1749–56.
*36Opdebeeck, C, Nelis, SM, Quinn, C, Clare, L. How does cognitive reserve impact on the relationships between mood, rumination, and cognitive function in later life? Aging Ment Health 2015; 19: 705–12.
*37O’Shea, DM, Fieo, RA, Hamilton, JL, Zahodne, LB, Manly, JJ, Stern, Y. Examining the association between late‐life depressive symptoms, cognitive function, and brain volumes in the context of cognitive reserve. Int J Geriatr Psychiatry 2015; 30: 614–22.
*38Bhalla, RK, Butters, MA, Zmuda, MD, Seligman, K, Mulsant, BH, Pollock, BGet al.Does education moderate neuropsychological impairment in late-life depression? Int J Geriatr Psychiatry 2005; 20: 413–17.
*39Potvin, O, Bergua, V, Meillon, C, Le Goff, M, Bouisson, J, Dartigues, Jet al.State anxiety and cognitive functioning in older adults. Am J Geriatr Psychiatry 2013; 21: 915–24.
*40Gale, CR, Allerhand, M, Deary, IJ. Is there a bidirectional relationship between depressive symptoms and cognitive ability in older people? A prospective study using the English Longitudinal Study of Ageing. Psychol Med 2012; 42: 2057–69.
*41Corsentino, EA, Collins, N, Sachs-Ericsson, N, Blazer, DG. Religious attendance reduces cognitive decline among older women with high levels of depressive symptoms. J Gerontol Biol Sci 2009; 64A: 1283–89.
*42Reyes-Ortiz, CA, Berges, IM, Raji, MA, Koenig, HG, Kuo, Y, Markides, KS. Church attendance mediates the association between depressive symptoms and cognitive functioning among older Mexican Americans. J Gerontol Biol Sci 2008; 63: 480–86.
*43Wilson, RS, de Leon, CFM, Bennett, DA, Bienias, JL, Evans, DA. Depressive symptoms and cognitive decline in a community population of older persons. J Neurol Neurosurg Psychiatry 2004; 75: 126–29.
*44Fuhrer, R, Antonucci, TC, Dartigues, J. The co-occurrence of depressive symptoms and cognitive impairment in a French community: are there gender differences? Eur Arch Psychiatry Clin Neurosci 1992; 242: 161–71.
*45Pálsson, S, Aevarsson, O, Skoog, I. Depression, cerebral atrophy, cognitive performance and incidence of dementia. Population study of 85-year-olds. Br J Psychiatry 1999; 174: 249–53.
*46Pálsson, S, Larsson, L, Tengelin, E, Waern, M, Samuelsson, S, Hallstro, Tet al.The prevalence of depression in relation to cerebral atrophy and cognitive performance in 70- and 74-year-old women in Gothenburg. The Women's Health Study. Psychol Med 2001; 31: 39–49.
*47Wight, RG, Aneshensel, CS, Seeman, TE. Educational attainment, continued learning experience, and cognitive function among older men. J Aging Health 2002; 14: 211–36.
*48Geerlings, MI, Schoevers, RA, Beekman, AT, Jonker, C, Deeg, DJ, Schmand, Bet al.Depression and risk of cognitive decline and Alzheimer's disease. Results of two prospective community-based studies in The Netherlands. Br J Psychiatry 2000; 176: 568–75.
*49Santos, NC, Costa, PS, Cunha, P, Portugal-Nunes, C, Amorim, L, Cotter, Jet al.Clinical, physical and lifestyle variables and relationship with cognition and mood in aging: a cross-sectional analysis of distinct educational groups. Frontiers in Aging Neuroscience 2014; 6: 21.
*50Avila, R, Moscoso, MAA, Ribeiz, S, Arrais, J, Jaluul, O, Bottino, CMC. Influence of education and depressive symptoms on cognitive function in the elderly. Int Psychogeriatr 2009; 21: 560–67.
*51Moraes, C, PintoJA, Jr JA, Jr, Lopes, MA, Litvoc, J, Bottino, CMC. Impact of sociodemographic and health variables on Mini-Mental State Examination in a community-based sample of older people. Eur Arch Psychiatry Clin Neurosci 2010; 260: 535–42.
52Nucci, M, Mapelli, D, Mondini, S. The cognitive reserve questionnaire (CRIq): a new instrument for measuring the cognitive reserve. Aging Clin Exp Res 2011; 23: 218–26.
53Richards, M, Deary, IJ. A life course approach to cognitive reserve: a model for cognitive aging and development? Ann Neurol 2005; 58: 617–22.
54Richards, M, Sacker, A. Lifetime antecedents of cognitive reserve. J Clin Exp Neuropsychol 2003; 25: 614–24.
55Sánchez Rodríguez, JL, Torrellas, C, Martín, J, Fernandez, MJ. Cognitive reserve and lifestyle in Spanish individuals with sporadic Alzheimer's disease. Am J Alzheimer's Disease Other Dementias 2011; 26: 542–54.
56Stern, Y. Cognitive reserve. Neuropsychologia 2009; 47: 2015–28
57Tucker, AM, Stern, Y. Cognitive reserve in aging. Current Alzheimer Research 2011; 8: 354–360.
58Whalley, LJ, Dick, FD, McNeill, G. A life-course approach to the aetiology of late-onset dementias. Lancet Neurology 2006; 5: 87–96.
59Folstein, MF, Folstein, SE, McHugh, PR. Mini-Mental State: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res 1975; 12: 189–98.
60Davey, A, Dai, T, Woodard, JL, Miller, LS, Gondo, Y, Johnson, MAet al.Profiles of cognitive functioning in a population-based sample of centenarians using factor mixture analysis. Exp Aging Res 2013; 39: 125–44.
61Leibovici, D, Ritchie, K, Ledésert, B, Touchon, J. Does education level determine the course of cognitive decline? Age Ageing 1996; 25: 392–97.
62Leung, GTY, Fung, AWT, Tam, CWC, Lui, VWC, Chiu, HFK, Chan, WMet al.Examining the association between participation in late-life leisure activities and cognitive function in community-dwelling elderly Chinese in Hong Kong. Int Psychogeriatr 2010; 22: 2–13.
63Mueller, AE, Raymond, N, Yochim, BP. Cognitive activity engagement predicts future memory and executive functioning in older adults. Act Adapt Aging 2013; 37: 251–64.
64Zahodne, LB, Nowinski, CJ, Gershon, RC, Manly, JJ. Which psychosocial factors best predict cognitive performance in older adults? Int J Geriatr Psychiatry 2014; 20: 487–95.
65Lyman, GH, Kuderer, NM. The strengths and limitations of meta-analyses based on aggregate data. BMC Medical Res Methodol 2005; 5: 14–21.
66Borenstein, M, Hedges, LV, Higgins, JPT, Rothstein, HR. Introduction to Meta-Analysis. Chichester: John Wiley & Sons Ltd; 2009.