Mental capacity is central to legal and ethical debates on the use of compulsion in psychiatry.

To describe the clinical epidemiology of mental incapacity in patients with psychiatric disorders, including interrater reliability of assessments, frequency in the psychiatric population and associations of mental incapacity.

Cross-sectional studies of capacity to consent to treatment for psychiatric patients were systematically reviewed from Medline, EMBASE and PsycInfo databases. Information on the reliability of assessments, frequency and associations of mental incapacity was extracted.

Out of 37 papers reviewed, 29 different capacity assessment tools were identified. Studies were highly heterogeneous in their measurement and definitions of capacity. Interrater reliabilities between tools were high. Studies indicate incapacity is common (median 29%) but the majority of psychiatric in-patients are capable of making treatment decisions. Psychosis, severity of symptoms, involuntary admission and treatment refusal were the strongest risk factors for incapacity.

Mental capacity can be reliably assessed. The majority of psychiatric in-patients have capacity, and socio-demographic variables do not have a major impact but clinical ones do.

The authors of a recent systematic review concluded that the use of non-pharmacological containment methods, excluding restraint and seclusion, was not supported by evidence. Their focus on randomised, controlled trials, however, does not reflect the research that has been, or could be, conducted.

To find empirically supported interventions that allow reduction in the use of seclusion in psychiatric facilities.

We reviewed English-language, peer-reviewed literature on interventions that allow reduction in the use of seclusion.

Staff typically used multiple interventions, including state-level support, state policy and regulation changes, leadership, examinations of the practice contexts, staff integration, treatment plan improvement, increased staff to patient ratios, monitoring seclusion episodes, psychiatric emergency response teams, staff education, monitoring of patients, pharmacological interventions, treating patients as active participants in seclusion reduction interventions, changing the therapeutic environment, changing the facility environment, adopting a facility focus, and improving staff safety and welfare.

Reducing seclusion rates is challenging and generally requires staff to implement several interventions.

Minority ethnic groups in the UK are reported to have a poor experience of mental health services, but comparative information is scarce.

To examine ethnic differences in patients' experience of community mental health services.

Trusts providing mental health services in England conducted surveys in 2004 and 2005 of users of community mental health services. Multiple regression was used to examine ethnic differences in responses.

About 27 000 patients responded to each of the surveys, of whom 10% were of minority ethnic origin. In the 2004 survey, age, living alone, detention and hospital admissions were stronger predictors of patient experience than ethnicity Self-reported mental health status had the strongest explanatory effect. In the 2005 survey, the main negative differences relative to the White British were for Asians.

Ethnicity had a smaller effect on patient experience than other variables. Relative to the White British, the Black group did not report negative experiences whereas the Asian group were most likely to respond negatively. However, there is a need for improvements in services for minority ethnic groups, including access to talking therapies and better recording of ethnicity.

The point prevalence of mental ill-health among adults with intellectual disabilities is 40.9%, but its incidence is unknown.

To determine the incidence and possible predictors of mental ill-health.

Prospective cohort study to measure mental ill-health in adults with mild to profound intellectual disabilities.

Cohort retention was 70% (n=651). The 2-year incidence of mental ill-health was 16.3% (12.6% excluding problem behaviours, and 4.6% for problem behaviours) and the standardised incidence ratio was 1.87 (95%CI1.51 2.28). Factors related to incident mental ill-health have some similarities with those in the general population, but also important differences. Type of accommodation and support, previous mental ill-health, urinary incontinence, not having impaired mobility, more severe intellectual disabilities, adult abuse, parental divorce in childhood and preceding life events predicted incident ill-health; however, deprivation, other childhood abuse or adversity, daytime occupation, and marital and smoking status did not.

This is a first step towards intervention trials, and identifying sub-populations for more proactive measures. Public health strategy and policy that is appropriate for this population should be developed.

Previous work suggests that the association between urbanicity and schizophrenia may be greatest in those with pre-existing vulnerability.

To test for synergism in risk of schizophrenia between population density and a combined exposure of poor premorbid social and cognitive functioning.

For 371 603 adolescent males examined by the Israeli Draft Board on social and cognitive functioning, data on population density of place of residence and later hospitalisation for schizophrenia were obtained from population-based registries.

There was an interaction between population density (five levels) and poor premorbid social and cognitive functioning (interaction χ2=4.6, P=0.032). The adjusted increase in cumulative incidence associated with one unit change in population density was 0.10% in the vulnerable group (95% CI 0.019–0.18, P=0.015), nine times larger than that in the non-vulnerable group (0.011%, 95% CI 0.0017–0.020, P=0.021).

Risk of schizophrenia may increase when people with a genetic liability to the disorder, expressed as poor social and cognitive functioning, need to cope with city life.

Progressive volumetric changes in the brains of people with schizophrenia have been attributed to a number of factors.

To determine whether glutamatergic changes in patients with schizophrenia correlated with grey-matter losses during the first years of illness.

Left anterior cingulate and thalamic glutamatergic metabolite levels and grey-matter volumes were examined in 16 patients with first-episode schizophrenia before and after 10 months and 30 months of antipsychotic treatment and in 16 healthy participants on two occasions 30 months apart.

Higher than normal glutamine levels were found in the anterior cingulate and thalamus of never-treated patients. Thalamic levels of glutamine were significantly reduced after 30 months. Limited grey-matter reductions were seen in patients at 10 months followed by widespread grey-matter loss at 30 months. Parietal and temporal lobe grey-matter loss was correlated with thalamic glutamine loss.

Elevated glutamine levels in never-treated patients followed by decreased thalamic glutamine and grey-matter loss in connected regions could indicate either neurodegeneration or a plastic response to reduced subcortical activity.

It is unclear how the recurrence of major depression in adolescence affects later life outcomes.

To examine the associations between the frequency of major depression at ages 16–21 and later outcomes, both before and after controlling for potentially confounding factors.

Data were gathered from a 25-year longitudinal study of a birth cohort of New Zealand children (n=982). Outcome measures included DSM–IV symptom criteria for major depression and anxiety disorders, suicidal ideation and attempted suicide, achieving university degree or other tertiary education qualification, welfare dependence and unemployment, and income at ages 21–25 years.

There were significant (P<0.05) associations between the frequency of depression at ages 16–21 years and all outcome measures. After adjustment for confounding factors, the association between frequency of depression and all mental health outcomes, and welfare dependence and unemployment, remained significant (P<0.05).

The frequency of depression in adolescence and young adulthood is associated with adverse mental health and economic outcomes in early adulthood.

Severe mental illness is associated with increased risk of aggressive behaviour, crime and victimisation. Mental health policy does not acknowledge this evidence. The number of forensic beds has risen dramatically.

To examine the prevalence of aggressive behaviour, victimisation and criminality among people receiving in-patient treatment for severe mental illness in an inner-city area.

Self-reports of aggressive behaviour and victimisation and criminal records were collected for 205 in-patients with severe mental illness.

In the preceding 6 months 49% of the men and 39% of the women had engaged in aggressive behaviour and 57% of the men and 48% of the women had been victims of assault; 47% of the men and 17% of the women had been convicted of at least one violent crime.

Aggressive behaviour and victimisation are common among severely mentally ill people requiring hospitalisation in the inner city. Rates of violent crime are higher than in the general population.