Arguments for and against evidence-based psychiatry have mostly centred on its value for clinical practice and teaching. Now, however, use of the same paradigm in evaluating health care has generated new problems.

To outline the development of evidence-based health care; to summarise the main critiques of this approach; to review the evidence now beingemployed to evaluate mental health care; and to consider how the evidence base might be improved.

The following sources were monitored: pub ications on evidence-based psychiatry and health care since 1990; reports of randomised trials and meta-analytic reviews to the end of 2002; and official British publications on mental health policy.

Although evidence-based health care is now being promulgated as a rational basis for mental health planning in Britain, its contributions to service evaluation have been distinctly modest. Only 10% of clinical trials and meta-analyses have been focused on effectiveness of services, and many reviews proved inconclusive.

The current evidence-based approach is overly reliant on meta-analytic reviews, and is more applicable to specific treatments than to the care agencies that control theirdelivery. A much broader evidence base is called for, extending to studies in primary health care and the evaluation of preventive techniques.

Accumulating evidence suggests that early-onset schizophrenia arises from a disturbance in the normal trajectory of cerebral development.

To investigate brain structure, asymmetry and IQ in early-onset schizophrenia.

Volumes of left and right cerebral hemispheres and IQ were assessed in 33 participants with early-onset DSM – IV schizophrenia and 30 members of a matched, normal control group.

Total brain volume was significantly smaller in the group with early-onset disease (‘cases’) relative to the control group (4.5%), especially for the left hemisphere in males (6.0%). A significant sex x diagnosis interaction in hemisphere asymmetry revealed that the female cases group had significantly reduced rightward asymmetry relative to the female control group and that the male cases tended to have reduced leftward asymmetry relative to the male control group. Decreased left hemisphere volume in males and decreased rightward hemispheric asymmetry in females correlated with reduced IQ.

Sexually dimorphic alterations in asymmetry correlate with degree of intellectual impairment in early-onset schizophrenia.

Despite the burden of depression, there remain few data on its economic consequences in an international context.

To explore the relationship between depression status (with and without medical comorbidity), work loss and health care costs, using cross-sectional data from a multi-national study of depression in primarycare.

Primarycare attendees were screened for depression. Those meeting eligibility criteria were categorised according to DSM – IV criteria for major depressive disorder and comorbid status. Unit costs were attached to self-reported days absent from work and uptake of health care services.

Medical comorbidity was associated with a 17–46% increase in health care costs in five of the six sites, but a clear positive association between costs and clinical depression status was identified in only one site.

The economic consequences of depression are influenced to a greater (and considerable) extent by the presence of medical comorbidity than by symptom severity alone.

Assertive outreach teams have been introduced in the UK, based on the assertive community treatment (ACT) model. It is unclear how models of community care translate from one culture to another or the degree of adaptation that may result.

To characterise London assertive outreach teams and determine whether there are distinct groups within them.

Semi-structured interviews with team managers plus one month's prospective process of care data collection were used to test for ‘model fidelity'to ACT and, by cluster analysis, to identify groupings.

Fidelity varied widely, with four teams (out of 24 studied) rated ‘high fidelity’ and three teams rated ‘low fidelity’ by US standards and 17 rated ‘ACT-like’. Three clusters were identified, with voluntary sector teams being the most distinct group.

There is wide variation in the practice of assertive outreach in London. The role of the voluntary sector requires increased attention. Heterogeneity in practice is a clinical challenge but a research opportunity in distinguishing effective from redundant components of the approach.

The job satisfaction, burn-out and work experiences of assertive outreach team staff are likely to be important to the model's sustainability.

To describe self-reported views and workexperiences of staff in London's 24 assertive outreach teams and to compare these with staff in community mental health teams (CMHTs) and between different types of assertive outreach team.

Confidential staff questionnaires in London's assertive outreach teams (n=l87, response rate= 89%) and nine randomly selected CMHTs (n=114, response rate=75%).

Staff in assertive outreach teams and CMHTs were moderately satisfied with their jobs, with similar sources of satisfaction and stress. Mean scores were low or average for all sub-scales of the Maslach Burnout Inventory for the assertive outreach team and the CMHT staff, with some differences suggesting less burn-out in the assertive outreach teams. Nine of the 24 assertive outreach teams had team means in the high range for emotional exhaustion and there were significant differences between types of assertive outreach team in some components of burn-out and satisfaction.

These findings are encouraging, but repeated investigation is needed when assertive outreach teams have been established for longer.

Although the model of assertive outreach has been widely adopted, it is unclear who receives assertive outreach in practice and what outcomes can be expected under routine conditions.

To assess patient characteristics and outcome in routine assertive outreach services in the UK.

Patients (n=580) were sampled from 24 assertive outreach teams in London. Outcomes – days spent in hospital and compulsory hospitalisation – were assessed over a 9-month follow-up.

The 6-month prevalence rate of substance misuse was 29%, and 35% of patients had been physically violent in the past 2 years. During follow-up, 39% were hospitalised and 25% compulsorily admitted. Outcome varied significantly between team types. These differences did not hold true when baseline differences in patient characteristics were controlled for.

Routine assertive outreach serves a wide range of patients with significant rates of substance misuse and violent behaviour. Over a 9-month period an average of 25% of assertive outreach patients can be expected to be hospitalised compulsorily. Differences in outcome between team types can be explained by differences in patient characteristics.

Information on suicide by psychiatric patients from ethnic minority groups is scarce.

To establish the number of patients from ethnic minorities who kill themselves; to describe their suicide methods, and their social and clinical characteristics.

A national clinical survey was based on a 4-year sample of suicides in England and Wales. Detailed data were collected on those who had been in contact with mental health services in the year before death.

In total 282 patients from ethnic minorities died by suicide – 6% of all patient suicides. The most common method of suicide was hanging; violent methods were more common than in White patient suicides. Schizophrenia was the most common diagnosis. Ethnic minority patients were more likely to have been unemployed than White patients and to have had a history of violence and recent non-compliance. In around half, this was the first episode of self-harm. Black Caribbean patients had the highest rates of schizophrenia (74%), unemployment, living alone, previous violence and drug misuse.

In order to reduce the number of suicides byethnicminority patients, services should address the complex health and social needs of people with severe mental illness.

Although there is a consensus that clozapine is more effective than conventional antipsychotic drugs for treatment-resistant schizophrenia, there is great heterogeneity among results of relevant trials.

To re-evaluate the evidence comparing clozapine with conventional antipsychotics and to investigate sources of heterogeneity.

Individual studies were inspected with assessment of clinical relevance of results. Meta-regression analysis was performed to investigate sources of heterogeneity.

Ten trials were examined. Recent large-scale studies have not found a substantial advantage for clozapine, especially in terms of a clinically relevant effect. Meta-regression showed that shorter study duration, financial support from a drug company and higher baseline symptom score consistently predicted greater advantage of clozapine.

It may be inappropriate to combine studies in meta-analysis, given the degree of heterogeneity between their findings. The benefits of clozapine compared with conventional treatment may not be substantial.