The ‘ethnic density hypothesis' is a proposition that members of ethnic minority groups may have better mental health when they live in areas with higher proportions of people of the same ethnicity. Investigations into this hypothesis have resulted in a complex and sometimes disparate literature.

To systematically identify relevant studies, summarise their findings and discuss potential explanations of the associations found between ethnic density and mental disorders.

A narrative review of studies published up to January 2011, identified through a systematic search strategy. Studies included have a defined ethnic minority sample; some measure of ethnic density defined at a geographical scale smaller than a nation or a US state; and a measure ascertaining mental health or disorder.

A total of 34 papers from 29 data-sets were identified. Protective associations between ethnic density and diagnosis of mental disorders were most consistent in older US ecological studies of admission rates. Among more recent multilevel studies, there was some evidence of ethnic density being protective against depression and anxiety for African American people and Hispanic adults in the USA. However, Hispanic, Asian–American and Canadian ‘visible minority’ adolescents have higher levels of depression at higher ethnic densities. Studies in the UK showed mixed results, with evidence for protective associations most consistent for psychoses.

The most consistent associations with ethnic density are found for psychoses. Ethnic density may also protect against other mental disorders, but presently, as most studies of ethnic density have limited statistical power, and given the heterogeneity of their study designs, our conclusions can only be tentative.

Clinicians have considerable difficulty identifying and helping those people with alcohol problems but no previous study has looked at this systematically.

To determine clinicians' ability to routinely identify broadly defined alcohol problems.

Data were extracted and rated by two authors, according to PRISMA standard and QUADAS criteria. Studies that examined the diagnostic accuracy of clinicians' opinion regarding the presence of alcohol problems as well as their written notation were evaluated.

A comprehensive search identified 48 studies that looked at the routine ability of clinicians to identify alcohol problems (12 in primary care, 31 in general hospitals and 5 in psychiatric settings). A total of 39 examined alcohol use disorder, 5 alcohol dependence and 4 intoxication. We separated studies into those using self-report and those using interview. The diagnostic sensitivity of primary care physicians (general practitioners) in the identification of alcohol use disorder was 41.7% (95% CI 23.0–61.7) but alcohol problems were recorded correctly in only 27.3% (95% CI 16.9–39.1) of primary care records. Hospital staff identified 52.4% (95% CI 35.9–68.7) of cases and made correct notations in 37.2% (95% CI 28.4–46.4) of case notes. Mental health professionals were able to correctly identify alcohol use disorder in 54.7% (95% CI 16.8–89.6) of cases. There were limited data regarding alcohol dependency and intoxication. Hospital staff were able to detect 41.7% (95% CI 16.5–69.5) of people with alcohol dependency and 89.8% (95% CI 70.4–99.4) of those acutely intoxicated. Specificity data were sparse.

Clinicians may consider simple screening methods such as self-report tools rather than relying on unassisted clinical judgement but the added value of screening over and above clinical diagnosis remains unclear.

There are calls to use patient-reported outcomes (PROs) routinely across mental health services. However, the use of PROs in patients with psychosis has been questioned.

To examine the concepts and measures of four widely used PROs: treatment satisfaction, subjective quality of life, needs for care and the quality of the therapeutic relationship.

We conducted a literature search of academic databases on concepts, characteristics and psychometric properties of the four PROs in patients with psychosis.

Although numerous concepts and measures have been published, evidence on the methodological quality of existing PROs is limited. Measures designed to assess distinct PROs showed a considerable conceptual, operational and empirical overlap, and some of them also included specific aspects. The impact of symptoms and cognitive deficits appears unlikely to be of clinical significance.

The popularity of PROs has not been matched with progress in their conceptualisation and measurement. Based on current evidence, some recommendations can be made. Distinct and short measures with clinical relevance and sufficient psychometric properties should be preferred. Future research should optimise the validity and measurement precision of PROs, while reducing assessment burden.

There is some concern that patients with mental illness may be in receipt of inferior medical care, including prescribed medication for medical conditions.

We aimed to quantify possible differences in the prescription of medication for medical conditions in those with v. without mental illness.

Systematic review and random effects meta-analysis with a minimum of three independent studies to warrant pooling by drug class.

We found 61 comparative analyses (from 23 publications) relating to the prescription of 12 classes of medication for cardiovascular health, diabetes, cancer, arthritis, osteoporosis and HIV in a total sample of 1931 509 people, in those with severe mental illness the adjusted odds ratio (OR) for an equitable prescription was 0.74 (95% CI 0.63-0.86), with lower than expected prescriptions for angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (ACE/ ARBs), beta-blockers and statins. People with affective disorder had an odds ratio of 0.75 (95% CI 0.55-1.02) but this was not significant. Individuals with a history of other (miscellaneous) mental illness had an odds ratio of 0.95 (95% CI 0.92-0.98) of comparable medication with lower receipt of ACE/ARBs but not highly active antiretroviral therapy (HAART) medication. Results were significant in both adjusted and unadjusted analyses.

Individuals with severe mental illness (including schizophrenia) appear to be prescribed significantly lower quantities of several common medications for medical disorders, largely for cardiovascular indications, although further work is required to clarify to what extent this is because of prescriber intent.

Post-conflict mental health studies in low-income countries have lacked pre-conflict data to evaluate changes in psychiatric morbidity resulting from political violence.

This prospective study compares mental health before and after exposure to direct political violence during the People's War in Nepal.

An adult cohort completed the Beck Depression Inventory and Beck Anxiety Inventory in 2000 prior to conflict violence in their community and in 2007 after the war.

Of the original 316 participants, 298 (94%) participated in the post-conflict assessment. Depression increased from 30.9 to 40.6%. Anxiety increased from 26.2 to 47.7%. Post-conflict post-traumatic stress disorder (PTSD) was 14.1%. Controlling for ageing, the depression increase was not significant. The anxiety increase showed a dose–response association with conflict exposure when controlling for ageing and daily stressors. No demographic group displayed unique vulnerability or resilience to the effects of conflict exposure.

Conflict exposure should be considered in the context of other types of psychiatric risk factors. Conflict exposure predicted increases in anxiety whereas socioeconomic factors and non-conflict stressful life events were the major predictors of depression. Research and interventions in postconflict settings therefore should consider differential trajectories for depression v. anxiety and the importance of addressing chronic social problems ranging from poverty to gender and ethnic/caste discrimination.

The prevelance of depression in older people is high, treatment is inadequate, it creates a substantial burden and is a public health priority for which exercise has been proposed as a therapeutic strategy.

To estimate the effect of exercise on depressive symptoms among older people, and assess whether treatment effect varies depending on the depression criteria used to determine participant eligibility.

Systematic review and meta-analysis of randomised controlled trials of exercise for depression in older people.

Nine trials met the inclusion criteria and seven were meta-analysed. Exercise was associated with significantly lower depression severity (standardised mean difference (SMD) =–0.34, 95% CI –0.52 to –0.17), irrespective of whether participant eligibility was determined by clinical diagnosis (SMD =–0.38, 95% CI –0.67 to –0.10) or symptom checklist (SMD =–0.34, 95% CI –0.62 to –0.06). Results remained significant in sensitivity analyses.

Our findings suggest that, for older people who present with clinically meaningful symptoms of depression, prescribing structured exercise tailored to individual ability will reduce depression severity.

Psychosocial interventions can improve behaviour and mood in people with dementia, but it is unclear how to maximise their effectiveness or acceptability in residential settings.

To understand what underlies the successful implementation of psychosocial interventions in care homes.

Systematic review and meta-synthesis of qualitative research.

The synthesis of 39 qualitative papers revealed that beneficial psychosocial interventions met the needs of people with dementia to connect with others, make a meaningful contribution and reminisce. Successful implementation rested on the active engagement of staff and family and the continuing provision of tailored interventions and support. This necessitated staff time, and raised issues around priorities and risk, but ultimately helped redefine staff attitudes towards residents and the caregiving role.

The findings from the meta-synthesis can help to inform the development and evaluation of psychosocial interventions in care homes and support their widespread implementation in clinical settings.

Attention is increasingly shifting towards the role of daily stressors in explaining mental health outcomes in humanitarian emergencies.

To assess the role of current perceived needs in explaining the association between past traumatic exposure and distress in humanitarian settings.

A series of mediator analyses were conducted, using data from Jordan (displaced Iraqi people) and Nepal (Bhutanese refugees). The General Health Questionnaire (GHQ-12), the newly developed Humanitarian Emergency Settings Perceived Needs Scale (HESPER) and the traumatic events list of the Composite International Diagnostic Interview (CIDI) were used as measures of distress, current perceived needs and past traumatic events respectively.

Current perceived needs were found to mediate the association between past traumatic exposure and distress in Jordan and, less strongly, in Nepal.

An integrated approach that includes a focus on daily stressors should be adopted to mitigate the impact of traumatic exposure in humanitarian settings.

There is an urgent need for effective, affordable interventions to prevent child mental health problems in low- and middle-income countries.

To determine the effects of a universal pre-school-based intervention on child conduct problems and social skills at school and at home.

In a cluster randomised design, 24 community pre-schools in inner-city areas of Kingston, Jamaica, were randomly assigned to receive the Incredible Years Teacher Training intervention (n = 12) or to a control group (n = 12). Three children from each class with the highest levels of teacher-reported conduct problems were selected for evaluation, giving 225 children aged 3–6 years. The primary outcome was observed child behaviour at school. Secondary outcomes were child behaviour by parent and teacher report, child attendance and parents' attitude to school. The study is registered as ISRCTN35476268.

Children in intervention schools showed significantly reduced conduct problems (effect size (ES) = 0.42) and increased friendship skills (ES = 0.74) through observation, significant reductions to teacher-reported (ES = 0.47) and parent-reported (ES = 0.22) behaviour difficulties and increases in teacher-reported social skills (ES = 0.59) and child attendance (ES = 0.30). Benefits to parents' attitude to school were not significant.

A low-cost, school-based intervention in a middle-income country substantially reduces child conduct problems and increases child social skills at home and at school.

Traumatic brain injury (TBI) is a concern of contemporary military deployments. Whether milder TBI leads to enduring impairment remains controversial.

To determine the influence of deployment TBI, and posttraumatic stress disorder (PTSD) and depression symptoms on neuropsychological and functional outcomes.

A sample of 760 US Army soldiers were assessed pre- and post-deployment. Outcomes included neuropsychological performances and subjective functional impairment.

In total, 9% of the participants reported (predominantly mild) TBI with loss of consciousness between pre- and post-deployment. At post-deployment, 17.6% of individuals with TBI screened positive for PTSD and 31.3% screened positive for depression. Before and after adjustment for psychiatric symptoms, TBI was significantly associated only with functional impairment. Both PTSD and depression symptoms adjusted for TBI were significantly associated with several neuropsychological performance deficits and functional impairment.

Milder TBI reported by deployed service members typically has limited lasting neuropsychological consequences; PTSD and depression are associated with more enduring cognitive compromise.

Treatment coverage for mental disorders ranges from less than 10% to more than 90% across low- and middle-income (LAMI) countries. Studies have yet to examine whether the capacity of mental health systems might be adversely affected by the burdens of unrelated conditions such as HIV/AIDS.

To examine whether the magnitude of disease burden from communicable, perinatal, maternal and nutritional conditions - commonly referred to as Group 1 diseases - is inversely associated with mental health system capacity in LAMI countries.

Multiple regression analyses were undertaken using data from 117 LAMI countries included in the 2011 World Health Organization (WHO) Mental Health Atlas. Capacity was defined in terms of human resources and infrastructure. Regressions controlled for effects of political stability, government health expenditures, income inequality and neuropsychiatric disease burden.

Higher Group 1 disease burden was associated with fewer psychiatrists, psychologists and nurses in the mental health sector, as well as reduced numbers of out-patient facilities and psychiatric beds in mental hospitals and general hospitals (t= −2.06 to −7.68, P < 0.05).

Evidence suggests that mental health system capacity in LAMI countries may be adversely affected by the magnitude of their Group 1 disease burden.