Relatively little is known of the use of systematic review and synthesis methods of non-randomised psychiatric epidemiological studies, which play a vital role in aetiological research, planning and policy-making.

To evaluate reviews of psychiatric epidemiological studies of functional mental disorders that employed synthesis methods such as systematic review or meta-analysis, or other forms of quantitative review.

We searched the literature to identify appropriate reviews published during the period 1996 to April 2009. Selected reviews were evaluated using published review guidelines.

We found 106 reviews in total, of which 38 (36%) did not mention method of data abstraction from primary studies at all. Many failed to mention study quality, publication bias, bias and confounding. In 73 studies that performed a meta-analysis, 58 (79%) tested for heterogeneity and of these, 47 found significant heterogeneity. Studies that detected heterogeneity made some allowance for this. A major obstacle facing reviewers is the wide variation between primary studies in the use of instruments to measure outcomes and in sampling methods used.

Many deficiencies found in systematic reviews are potentially remediable, although synthesis of primary study findings in a field characterised by so many sources of heterogeneity will remain challenging.

The efficacy of psychopharmacological treatments has been called into question. Psychiatrists are unfamiliar with the effectiveness of common medical drugs.

To put the efficacy of psychiatric drugs into the perspective of that of major medical drugs.

We searched Medline and the Cochrane Library for systematic reviews on the efficacy of drugs compared with placebo for common medical and psychiatric disorders, and systematically presented the effect sizes for primary efficacy outcomes.

We included 94 meta-analyses (48 drugs in 20 medical diseases, 16 drugs in 8 psychiatric disorders). There were some general medical drugs with clearly higher effect sizes than the psychotropic agents, but the psychiatric drugs were not generally less efficacious than other drugs.

Any comparison of different outcomes in different diseases can only serve the purpose of a qualitative perspective. The increment of improvement by drug over placebo must be viewed in the context of the disease's seriousness, suffering induced, natural course, duration, outcomes, adverse events and societal values.

Late-life depression may differ from early-life depression in its phenomenology.

To investigate the effect of age on the phenomenology of major depression.

A systematic search was conducted in PubMed, Embase and PsycINFO for all studies examining the relation between age and phenomenology of major depression according to RDC, DSM and ICD criteria. Studies were included only if the age groups were compared at the single-item level using the 17-, 21- or 24-item versions of the Hamilton Rating Scale for Depression; a meta-analysis was done for each item of the 17-item scale.

Eleven papers met the inclusion criteria. Older depressed adults, compared with younger depressed adults, demonstrated more agitation, hypochondriasis and general as well as gastrointestinal somatic symptoms, but less guilt and loss of sexual interest.

The phenomenology of late-life depression differs only in part from that of early-life depression. Major depression in older people may have a more somatic presentation, whereas feelings of guilt and loss of sexual function may be more prevalent in younger people.

Previous research suggests that various types of childhood maltreatment frequently co-occur and confer risk for multiple psychiatric diagnoses. This non-specific pattern of risk may mean that childhood maltreatment increases vulnerability to numerous specific psychiatric disorders through diverse, specific mechanisms or that childhood maltreatment engenders a generalised liability to dimensions of psychopathology. Although these competing explanations have different implications for intervention, they have never been evaluated empirically.

We used a latent variable approach to estimate the associations of childhood maltreatment with underlying dimensions of internalising and externalising psychopathology and with specific disorders after accounting for the latent dimensions. We also examined gender differences in these associations.

Data were drawn from a nationally representative survey of 34 653 US adults. Lifetime DSM-IV psychiatric disorders were assessed using the AUDADIS-IV. Physical, sexual and emotional abuse and neglect were assessed using validated measures. Analyses controlled for other childhood adversities and sociodemographics.

The effects were fully mediated through the latent liability dimensions, with an impact on underlying liability levels to internalising and externalising psychopathology rather than specific psychiatric disorders. Important gender differences emerged with physical abuse associated only with externalising liability in men, and only with internalising liability in women. Neglect was not significantly associated with latent liability levels.

The association between childhood maltreatment and common psychiatric disorders operates through latent liabilities to experience internalising and externalising psychopathology, indicating that the prevention of maltreatment may have a wide range of benefits in reducing the prevalence of many common mental disorders. Different forms of abuse have gender-specific consequences for the expression of internalising and externalising psychopathology, suggesting gender-specific aetiological pathways between maltreatment and psychopathology.

Recent evidence points to partially shared genetics of neuropsychiatric disorders.

We examined risk of intellectual disability and other neuropsychiatric outcomes in 3174 children of mothers with schizophrenia, bipolar disorder or unipolar major depression compared with 3129 children of unaffected mothers.

We used record linkage across Western Australian population-based registers. The contribution of obstetric factors to risk of intellectual disability was assessed.

Children were at significantly increased risk of intellectual disability with odds ratios (ORs) of 3.2 (95% CI 1.8–5.7), 3.1 (95% CI 1.9–4.9) and 2.9 (95% CI 1.8–4.7) in the maternal schizophrenia, bipolar disorder and unipolar depression groups respectively. Multivariate analysis suggests familial and obstetric factors may contribute independently to the risk. Although summated labour/delivery complications (OR = 1.4, 95% CI 1.0–2.0) just failed to reach significance, neonatal encephalopathy (OR = 7.7, 95% CI 3.0–20.2) and fetal distress (OR = 1.8, 95% CI 1.1–2.7) were independent significant predictors. Rates of rare syndromes in children of mothers with mental disorder were well above population rates. Risk of pervasive developmental disorders, including autism, was significantly elevated for children of mothers with bipolar disorder. Risk of epilepsy was doubled for children of mothers with unipolar depression.

Our findings provide epidemiological support for clustering of neuropsychiatric disorders. Further larger epidemiological studies are warranted.

Mental and physical disorders are associated with total disability, but their effects on days with partial disability (i.e. the ability to perform some, but not full-role, functioning in daily life) are not well understood.

To estimate individual (i.e. the consequences for an individual with a disorder) and societal effects (i.e. the avoidable partial disability in the society due to disorders) of mental and physical disorders on days with partial disability around the world.

Respondents from 26 nationally representative samples (n = 61 259, age 18+) were interviewed regarding mental and physical disorders, and day-to-day functioning. The Composite International Diagnostic Interview, version 3.0 (CIDI 3.0) was used to assess mental disorders; partial disability (expressed in full day equivalents) was assessed with the World Health Organization Disability Assessment Schedule in the CIDI 3.0.

Respondents with disorders reported about 1.58 additional disability days per month compared with respondents without disorders. At the individual level, mental disorders (especially post-traumatic stress disorder, depression and bipolar disorder) yielded a higher number of days with disability than physical disorders. At the societal level, the population attributable risk proportion due to physical and mental disorders was 49% and 15% respectively.

Mental and physical disorders have a considerable impact on partial disability, at both the individual and at the societal level. Physical disorders yielded higher effects on partial disability than mental disorders.

Psychological therapies have been shown to be effective in the treatment of depression. However, evidence is focused on individually delivered therapies, with less evidence for group-based therapies.

To conduct a systematic review and meta-analysis of the efficacy of group-based psychological therapies for depression in primary care and the community.

We searched MEDLINE, Embase, PsycINFO, the Cochrane Central Register of Controlled Trials and the Cochrane Collaboration Depression, Anxiety and Neurosis Review Group database from inception to July 2010. The Cochrane risk of bias methodology was applied.

Twenty-three studies were included. The majority showed considerable risk of bias. Analysis of group cognitive–behavioural therapy (CBT) v. usual care alone (14 studies) showed a significant effect in favour of group CBT immediately post-treatment (standardised mean difference (SMD) −0.55 (95% CI −0.78 to −0.32)). There was some evidence of benefit being maintained at short-term (SMD =–0.47 (95% CI −1.06 to 0.12)) and medium- to long-term follow-up (SMD =–0.47 (95% CI – 0.87 to −0.08)). Studies of group CBT v. individually delivered CBT therapy (7 studies) showed a moderate treatment effect in favour of individually delivered CBT immediately post-treatment (SMD = 0.38 (95% CI 0.09–0.66)) but no evidence of difference at short- or medium- to long-term follow-up. Four studies described comparisons for three other types of group psychological therapies.

Group CBT confers benefit for individuals who are clinically depressed over that of usual care alone. Individually delivered CBT is more effective than group CBT immediately following treatment but after 3 months there is no evidence of difference. The quality of evidence is poor. Evidence about group psychological therapies not based on CBT is particularly limited.

Associations between specific parent and offspring mental disorders are likely to have been overestimated in studies that have failed to control for parent comorbidity.

To examine the associations of parent with respondent disorders.

Data come from the World Health Organization (WHO) World Mental Health Surveys (n = 51 507). Respondent disorders were assessed with the Composite International Diagnostic Interview and parent disorders with informant-based Family History Research Diagnostic Criteria interviews.

Although virtually all parent disorders examined (major depressive, generalised anxiety, panic, substance and antisocial behaviour disorders and suicidality) were significantly associated with offspring disorders in multivariate analyses, little specificity was found. Comorbid parent disorders had significant sub-additive associations with offspring disorders. Population-attributable risk proportions for parent disorders were 12.4% across all offspring disorders, generally higher in high- and upper-middle- than low-/lower-middle-income countries, and consistently higher for behaviour (11.0–19.9%) than other (7.1–14.0%) disorders.

Parent psychopathology is a robust non-specific predictor associated with a substantial proportion of offspring disorders.

A propensity to attend to other people's emotions is a necessary condition for human empathy.

To test our hypothesis that psychopathic disorder begins as a failure to attend to the eyes of attachment figures, using a ‘love’ scenario in young children.

Children with oppositional defiant disorder, assessed for callous–unemotional traits, and a control group were observed in a love interaction with mothers. Eye contact and affection were measured for each dyad.

There was no group difference in affection and eye contact expressed by the mothers. Compared with controls, children with oppositional defiant disorder expressed lower levels of affection back towards their mothers; those with high levels of callous–unemotional traits showed significantly lower levels of affection than the children lacking these traits. As predicted, the former group showed low levels of eye contact toward their mothers. Low eye contact was not correlated with maternal coercive parenting or feelings toward the child, but was correlated with psychopathic fearlessness in their fathers.

Impairments in eye contact are characteristic of children with callous–unemotional traits, and these impairments are independent of maternal behaviour.

People with 22q11.2 deletion syndrome (velo-cardio-facial syndrome) have a 30-fold risk of developing schizophrenia. In the general population the schizophrenia phenotype includes a cognitive deficit and a decline in academic performance preceding the first episode of psychosis in a subgroup of patients. Findings of cross-sectional studies suggest that cognitive abilities may decline over time in some children with 22q11.2 deletion syndrome. If confirmed longitudinally, this could indicate that one or more genes within 22q11.2 are involved in cognitive decline.

To assess longitudinally the change in IQ scores in children with 22q11.2 deletion syndrome.

Sixty-nine children with the syndrome were cognitively assessed two or three times at set ages 5.5 years, 7.5 years and 9.5 years.

A mean significant decline of 9.7 Full Scale IQ points was found between ages 5.5 years and 9.5 years. In addition to the overall relative decline that occurred when results were scored according to age-specific IQ norms, in 10 out of a group of 29 children an absolute decrease in cognitive raw scores was found between ages 7.5 years and 9.5 years. The decline was not associated with a change in behavioural measures.

The finding of cognitive decline can be only partly explained as the result of ‘growing into deficit’; about a third of 29 children showed an absolute loss of cognitive faculties. The results underline the importance of early psychiatric screening in this population and indicate that further study of the genes at the 22q11.2 locus may be relevant to understanding the genetic basis of early cognitive deterioration.

Self-help interventions for psychiatric disorders represent an increasingly popular alternative to therapist-administered psychological therapies, offering the potential of increased access to cost-effective treatment.

To determine the efficacy, cost-effectiveness and acceptability of self-help interventions for anxiety disorders.

Randomised controlled trials (RCTs) of self-help interventions for anxiety disorders were identified by searching nine online databases. Studies were grouped according to disorder and meta-analyses were conducted where sufficient data were available. Overall meta-analyses of self-help v. waiting list and therapist-administered treatment were also undertaken. Methodological quality was assessed independently by two researchers according to criteria set out by the Cochrane Collaboration.

Thirty-one RCTs met inclusion criteria for the review. Results of the overall meta-analysis comparing self-help with waiting list gave a significant effect size of 0.84 in favour of self-help. Comparison of self-help with therapist-administered treatments revealed a significant difference in favour of the latter with an effect size of 0.34. The addition of guidance and the presentation of multimedia or web-based self-help materials improved treatment outcome.

Self-help interventions appear to be an effective way of treating individuals diagnosed with social phobia and panic disorder. Further research is required to evaluate the cost-effectiveness and acceptability of these interventions.

High levels of psychiatric morbidity in prisoners have been documented in many countries, but it is not known whether rates of mental illness have been increasing over time or whether the prevalence differs between low–middle-income countries compared with high-income ones.

To systematically review prevalence studies for psychotic illness and major depression in prisoners, provide summary estimates and investigate sources of heterogeneity between studies using meta-regression.

Studies from 1966 to 2010 were identified using ten bibliographic indexes and reference lists. Inclusion criteria were unselected prison samples and that clinical examination or semi-structured instruments were used to make DSM or ICD diagnoses of the relevant disorders.

We identified 109 samples including 33 588 prisoners in 24 countries. Data were meta-analysed using random-effects models, and we found a pooled prevalence of psychosis of 3.6% (95% CI 3.1–4.2) in male prisoners and 3.9% (95% CI 2.7–5.0) in female prisoners. There were high levels of heterogeneity, some of which was explained by studies in low–middle-income countries reporting higher prevalences of psychosis (5.5%, 95% CI 4.2–6.8; P=0.035 on meta-regression). The pooled prevalence of major depression was 10.2% (95% CI 8.8–11.7) in male prisoners and 14.1% (95% CI 10.2–18.1) in female prisoners. The prevalence of these disorders did not appear to be increasing over time, apart from depression in the USA (P=0.008).

High levels of psychiatric morbidity are consistently reported in prisoners from many countries over four decades. Further research is needed to confirm whether higher rates of mental illness are found in low- and middle-income nations, and examine trends over time within nations with large prison populations.

Recent studies have examined gene×environment (G×E) interactions involving the monoamine oxidase A (MAOA) gene in moderating the associations between exposure to adversity and antisocial behaviour. The present study examined a novel method for assessing interactions between a single gene and multiple risk factors related to environmental and personal adversity.

To test the hypothesis that the presence of the low-activity MAOA genotype was associated with an increased response to a series of risk factors.

Participants were 399 males from the Christchurch Health and Development Study who had complete data on: (a) MAOA promoter region variable number tandem repeat genotype; (b) antisocial behaviour (criminal offending) to age 30 and convictions to age 21; and (c) maternal smoking during pregnancy, IQ, childhood maltreatment and school failure.

Poisson regression models were fitted to three antisocial behaviour outcomes (property/violent offending ages 15–30; and convictions ages 17–21), using measures of exposure to adverse childhood circumstances. The analyses revealed consistent evidence of G x E interactions, such that those with the low-activity MAOA variant who were exposed to adversity in childhood were significantly more likely to report offending in late adolescence and early adulthood.

The present findings add to the evidence suggesting that there is a stable G x E interaction involving MAOA, a range of adverse environmental and personal factors, and antisocial behaviour across the life course. These analyses also demonstrate the utility of using multiple environmental/personal exposures to test G×E interactions.