Controversy remains as to whether cannabis acts as a causal risk factor for schizophrenia or other functional psychotic illnesses.

To examine critically the evidence that cannabis causes psychosis using established criteria of causality.

We identified five studies that included a well-defined sample drawn from population-based registers or cohorts and used prospective measures of cannabis use and adult psychosis.

On an individual level, cannabis use confers an overall twofold increase in the relative risk for later schizophrenia. At the population level, elimination of cannabis use would reduce the incidence of schizophrenia by approximately 8%, assuming a causal relationship. Cannabis use appears to be neither a sufficient nor a necessary cause for psychosis. It is a component cause, part of a complex constellation of factors leading to psychosis.

Cases of psychotic disorder could be prevented by discouraging cannabis use among vulnerable youths. Research is needed to understand the mechanisms by which cannabis causes psychosis.

Antisocial behaviour in adult life has its roots in childhood.

To explore the independent and joint effects of childhood characteristics on the persistence of antisocial behaviour into adult life.

A clinical sample of twins who were systematically ascertained in childhood was followed up 10–25 years later. A total of 225 twins were interviewed regarding childhood and adult psychiatric disorder, psychosocial functioning, and psychosocial and cognitive risk factors.

In univariate analyses, childhood hyperactivity and conduct disorder showed equally strong prediction of antisocial personality disorder (ASPD) and criminality in early and mid-adult life. Lower IQ and reading problems were most prominent in their relationships with childhood and adolescent antisocial behaviour. In multivariate modelling childhood conduct disorder and hyperactivity predicted adult ASPD even when intervening risk factors were accounted for. The number of hyperactive and conduct symptoms also predicted adult outcome.

Childhood disruptive behaviour has powerful long-term effects on adult antisocial outcomes, which continue into middle adulthood. The importance of number of symptoms, the presence of disruptive disorder, and intermediate experiences highlight three areas where interventions might be targeted.

In previous functional magnetic resonance imaging (fMRI) studies, participants with schizophrenia showed decreased language lateralisation, resulting from increased activation of the right hemisphere compared with controls.

To determine whether decreased lateralisation and increased right cerebral language activation constitute genetic predispositions for schizophrenia.

Language activation was measured using fMRI in 12 right-handed monozygotic twin pairs discordant for schizophrenia and 12 healthy right-handed monozygotic twin pairs who were matched for gender, age and education.

Language lateralisation was decreased in discordant twin pairs compared with the healthy twin pairs. The groups did not differ in activation of the language-related areas of the left hemisphere, but language-related activation in the right hemisphere was significantly higher in the discordant twin pairs than in the healthy pairs. Within the discordant twin pairs, language lateralisation was not significantly different between patients with schizophrenia and their co-twins.

Decreased language lateralisation may constitute a genetic predisposition for schizophrenia.

There is accumulating evidence of hypothalamic–pituitary–adrenal (HPA) axis disturbances in chronic fatigue syndrome (CFS). The salivary cortisol response to awakening has been described recently as a non-invasive test of the capacity of the HPA axis to respond to stress. The results of this test correlate closely with those of more invasive dynamic tests reported in the literature; furthermore, it can be undertaken in a naturalistic setting.

To assess the HPA axis using the salivary cortisol response to awakening in CFS.

We measured salivary cortisol upon awakening and 10, 20, 30 and 60 min afterwards in 56 patients with CFS and 35 healthy volunteers.

Patients had a lower cortisol response to awakening, measured by the area under the curve.

This naturalistic test of the HPA axis response to stress showed impaired HPA axis function in CFS.

An earlier trial demonstrated good outcomes after 1 year for patients with chronic fatigue syndrome (CFS) who received an educational intervention designed to encourage graded activity.

To determine 2-year outcomes for the same treated patients and the response to treatment of patients formerly in the control condition.

Patients in the treatment groups (n=114) were followed up at 2 years; 32 patients from the control group were offered the intervention after 1 year and were assessed 1 year later. Assessments were the self-rated measures used in the original trial.

At 2 years 63 of the treated patients (55%) no longer fulfilled trial criteria for CFS compared with 64 patients (56%) at 1 year. Fourteen of 30 crossover patients (47%) achieved a good outcome at 1 year and seven (23%) no longer fulfilled criteria for CFS.

Benefits of the intervention were maintained at 2 years. Delaying treatment is associated with reduced efficacy and required more intensive therapy.

France has high rates of psychotropic drug consumption and suicide in the elderly population, but it has not yet been possible to determine whether this is due to exceptionally high morbidity rates.

To describe the first longitudinal population study of psychiatric disorder undertaken in France, and to estimate current and lifetime prevalences and age of onset of psychiatric disorder.

A study group of 1873 non-institutionalised persons aged 65 years and over was randomly recruited from the Montpellier district electoral rolls. The Mini International Neuropsychiatric Interview was used to assess current and lifetime symptoms. Cases identified by the application of DSM–IV criteria were reexamined by a clinical panel.

Forty-six percent of the study population had experienced a mental disorder in their lifetime, and 3.7% had made a suicide attempt. Lifetime prevalence of major depression was 26.5% and 30% for anxiety disorders. Current prevalence rates were 14.2% for anxiety disorders, 10.7% for phobia, 3% for major depression and 1.7% for psychosis.

Results show very high rates of lifetime but not current major depression. Rates of current phobia and suicidal ideation in the very elderly are also high compared with other studies. The rates reported are likely to be underestimates.

The ICD–10 categorisation of severity of depression into mild, moderate and severe depressive episodes has not been validated.

To validate the ICD–10 categorisation of severity of depression by estimating its predictive ability on the course of illness and suicidal outcome.

All psychiatric in-patients in Denmark who had received a diagnosis of a single depressive episode at their first discharge between 1994 and 1999 were identified. The risk of relapse and the risk of suicide were compared for patients discharged with an ICD–10 diagnosis of a single mild, moderate or severe depressive episode.

At their first discharge, 1103 patients had an ICD–10 diagnosis of mild depressive episode, 3182 had a diagnosis of moderate depressive episode and 2914 had a diagnosis of severe depressive episode. The risk of relapse and the risk of suicide were significantly different for the three types of depression – increasing from mild to moderate to severe depressive episode.

The ICD–10 way of grading severity is clinically useful and should be preserved in future versions.

Major depressive disorder is the second leading cause of disability-adjusted life-years in developed regions of the world and antidepressants are the third-ranking therapy class worldwide.

To test the public health impact of the escalating sales of antidepressants.

Nationwide data from Iceland are used as an example to study the effect of sales of antidepressants on suicide, disability, hospital admissions and outpatient visits.

Sales of antidepressants increased from 8.4 daily defined doses per 1000 inhabitants per day in 1975 to 72.7 in 2000, which is a user prevalence of 8.7% for the adult population. Suicide rates fluctuated during 1950–2000 but did not show any definite trend. Rates for outpatient visits increased slightly over the period 1989–2000 and admission rates increased even more. The prevalence of disability due to depressive and anxiety disorders has not decreased over the past 25 years.

The dramatic increase in the sales of antidepressants has not had any marked impact on the selected public health measures. Obviously, better treatment for depressive disorders is still needed in order to reduce the burden caused by them.

Despite the tendency for harmonisation of strategies for mental health care delivery, rules and regulations for involuntary placement or treatment of mentally ill persons still differ remarkably internationally. Rapid European integration and other political developments require valid and reliable international overviews, sound studies and profound analyses of this controversial issue.

To give an overview of compulsory admission data from official sources across the European Union (EU).

Data on the legal frameworks for involuntary placement or treatment of people with mental illness and their outcomes were provided and assessed by experts from all EU member states.

Total frequencies of admission and compulsory admission rates vary remarkably across the EU. Variation hints at the influence of differences in legal frameworks or procedures. Time series suggest an overall tendency towards more or less stable quotas in most member states.

Further research is greatly needed in this field. Common international health reporting standards are essential to the compilation of basic data.

There is a lack of comparative data on the prevalence and effects of exposure to violence in African youth.

We assessed trauma exposure, post-traumatic stress symptoms and gender differences in adolescents from two African countries.

A sample of 2041 boys and girls from 18 schools in Cape Town and Nairobi completed anonymous self-report questionnaires.

More than 80% reported exposure to severe trauma, either as victims or witnesses. Kenyan adolescents, compared with South African, had significantly higher rates of exposure to witnessing violence (69% v. 58%), physical assault by a family member (27% v. 14%) and sexual assault (18% v. 14%). But rates of current full-symptom post-traumatic stress disorder (PTSD) (22.2% v. 5%) and current partial-symptom PTSD (12% v. 8%) were significantly higher in the South African sample. Boys were as likely as girls to meet PTSD symptom criteria.

Although the lifetime exposure to trauma was comparable across both settings, Kenyan adolescents had much lower rates of PTSD. This difference may be attributable to cultural and other trauma-related variables. High rates of sexual assault and PTSD, traditionally documented in girls, may also occur in boys and warrant further study.

Stigma defines people in terms of some distinguishing characteristic and devalues them as a consequence.

To describe the relationship of stigma with mental illness, psychiatric diagnosis, treatment and its consequences of stigma for the individual.

Narrative interviews were conducted by trained users of the local mental health services; 46 patients were recruited from community and day mental health services in North London.

Stigma was a pervasive concern to almost all participants. People with psychosis or drug dependence were most likely to report feelings and experiences of stigma and were most affected by them. Those with depression, anxiety and personality disorders were more affected by patronising attitudes and feelings of stigma even if they had not experienced any overt discrimination. However, experiences were not universally negative.

Stigma may influence how a psychiatric diagnosis is accepted, whether treatment will be adhered to and how people with mental illness function in the world. However, perceptions of mental illness and diagnoses can be helpful and non-stigmatising for some patients.