Previous studies of differences in mental health between urban and rural populations are inconsistent.

To examine whether a high level of urbanisation is associated with increased incidence rates of psychosis and depression, after adjustment for age, marital status, education and immigrant status.

Follow-up study of the total Swedish population aged 25–64 years with respect to first hospital admission for psychosis or depression. Level of urbanisation was defined by population density and divided into quintiles.

With increasing levels of urbanisation the incidence rates of psychosis and depression rose. In the full models, those living in the most densely populated areas (quintile 5) had 68–77% more risk of developing psychosis and 12–20% more risk of developing depression than the reference group (quintile 1).

A high level of urbanisation is associated with increased risk of psychosis and depression for both women and men.

Few South American studies have examined current prevalence rates of psychiatric disorders.

To examine prevalence rates in a nationally representative adult population from Chile.

The Composite International Diagnostic Interview was administered to a stratified random sample of 2978 individuals from four provinces representative of the country's population. Six-month and 1-month prevalence rates were estimated. Demographic correlates, comorbidity and service use were examined.

Nearly a fifth of the Chilean population had had a psychiatric disorder during the preceding 6 months. The 6-month and 1-month prevalence rates were 19.7% and 16.7% respectively. For the 6-month prevalence the five most common disorders were simple phobia, social phobia, agoraphobia, major depressive disorder and alcohol dependence. Less than 30% of those with any psychiatric diagnosis had a comorbid psychiatric disorder and the majority of them had sought treatment from mental health services.

Current prevalence studies are useful indicators of service needs. People with comorbid psychiatric conditions have high rates of service use. The low rate of comorbidity in Chile merits further study.

There is growing evidence of a relationship between frontal neuroimaging and neuropsychological abnormalities and the physiopathology and course of late-onset major depression.

To assess acute antidepressant response in late-onset major depression in relation to baseline frontal perfusion ratios.

A 99mTc HMPAO single photon emission computed tomographic brain scan was performed in medication-free patients with late-onset major depression, who were then included in a 12-week antidepressant treatment regimen. Logistic regression was used to define a predictive model of non-remission.

Atotal of 47 patients completed the study 34 of whom were classed as remitters and 13 as non-remitters. The variable left anterior fronto-cerebellar perfusion ratio had a global predictive power of 87%. Analysing this variable together with the baseline variables age of onset and duration of index episode, the predictive power of the model rose to 94%.

Our study suggests that a specific frontal functioning could predict the acute antidepressant response in late-onset severe major depression.

Command hallucinations are a distressing and high-risk group of symptoms that have long been recognised but little understood, with few effective treatments. In line with our recent research, we propose that the development of an effective cognitive therapy for command hallucinations (CTCH) would be enhanced by applying insights from social rank theory.

We tested the efficacy of CTCH in reducing beliefs about the power of voices and thereby compliance, in a single-blind, randomised controlled trial.

A total of 38 patients with command hallucinations, with which they had recently complied with serious consequences, were allocated randomly to CTCH or treatment as usual and followed up at 6 months and 12 months.

Large and significant reductions in compliance behaviour were obtained favouring the cognitive therapy group (effect size=1.1). Improvements were also observed in the CTCH but not the control group in degree of conviction in the power and superiority of the voices and the need to comply, and in levels of distress and depression. No change in voice topography (frequency, loudness, content) was observed. The differences were maintained at 12 months' follow-up.

The results support the efficacy of cognitive therapy for CTCH.

Even at the first episode of psychosis, high expressed emotion (EE) characterises over half of patient–carer relationships. This study compared a carer appraisal model of EE with the ability of illness factors to predict EE at the first episode.

To investigate the utility of a carer appraisal model of EE in first-episode psychosis.

We compared high- and low-EE carers of people who had first-episode psychosis (n=46).

High EE in carers was associated with higher avoidant coping, higher subjective burden and lower perceived patient interpersonal functioning. Patient illness factors and carers ‘distress levels were not associated with EE.

Even at the first episode, carers' psychological appraisal, not patient illness factors, is influential in determining high EE. Carers ‘appraisal of their situation should be a primary target to lower or prevent high EE in early intervention for psychosis.

It has been suggested that psychosis genes might be associated with beneficial effects, explaining their high frequency in all human populations.

To test the relationship between academic success and the incidence of psychotic disorders.

The unusually complete demographic and scholastic records available in Iceland were used to locate academically accomplished individuals and assess the probability of previously identified patients with mental disorders and their relatives being among such groups.

Close relatives of successful students showed increased risks of psychosis. Individuals who subsequently developed psychosis and relatives of people with psychosis excelled in school performance, particularly in mathematics.

The study supports the hypothesis that stimulation associated with psychotic tendencies enhances performance in academic settings.

Few follow-up studies of depression have evaluated depressive symptomatology over time at both threshold and sub-threshold levels.

To evaluate long-term longitudinal symptomatic course after an episode of severe depression.

A total of 61 participants from a previous study cohort underwent a detailed interview covering the longitudinal course of depression and pharmacological treatment over 8–11 years of follow-up.

Of the follow-up months, 52% were spent at an asymptomatic level, 15% at minor symptom level, 20% at residual symptom level and 13% at full depression level. Also, 30% of follow-up months were spent in an episode of depression, and 18% of patients never achieved asymptomatic status during follow-up. The percentage of patients at each symptom level remained relatively stable after the first 2 years, but levels in individuals fluctuated, with a mean of two changes in symptom levels per follow-up year.

After severe episodes, sub-syndromal levels of depression are common and persistent, with considerable fluctuation suggesting a continuum between sub-syndromal subtypes and full depression.

Few controlled studies have examined the use of atypical antipsychotic drugs for prevention of relapse in patients with bipolar I disorder.

To evaluate whether olanzapine plus either lithium or valproate reduces the rate of relapse, compared with lithium or valproate alone.

Patients achieving syndromic remission after 6 weeks'treatment with olanzapine plus either lithium (0.6–1.2 mmol/l) or valproate (50–125 μg/ml) received lithium or valproate plus either olanzapine 5–20 mg/day (combination therapy) or placebo (monotherapy), and were followed in a double-masked trial for 18 months.

The treatment difference in time to relapse into either mania or depression was not significant for syndromic relapse (median time to relapse: combination therapy 94 days, monotherapy40.5 days; P=0.742), but was significant for symptomatic relapse (combination therapy 163 days, monotherapy42 days; P=0.023).

Patients taking olanzapine added to lithium or valproate experienced sustained symptomatic remission, but not syndromic remission, for longer than those receiving lithium or valproate monotherapy.

Relapse is one of the most costly aspects of schizophrenia.

To compare costs, clinical outcomes and quality of life for patients who experienced relapse in schizophrenia with a control group who did not relapse.

Patients were randomly selected from current psychiatric case-loads drawn from urban and suburban areas of Leicester. Differences in costs and outcomes by relapse status in the previous 6 months were examined using parametric and non-parametric tests, and multivariate analysis was used to examine factors associated with relapse and costs.

Costs for the patients who relapsed were over four times higher than those for the non-relapse group. There were few statistically significant differences in clinical and quality of life measures by relapse status. Multivariate analyses suggested some significant correlates of relapse and costs.

The higher costs associated with relapse will be of interest to policy-makers who face difficult choices concerning new but more expensive treatments for patients with schizophrenia.

Querulous paranoia may have disappeared from the psychiatric literature, but is it flourishing in modern complaints organisations and the courts? Aims To investigate the unusually persistent complainants who lay waste to their own lives and place inordinate demands and stress on complaints organisations.

Complaints officers completed questionnaires on both unusually persistent complainants and matched controls.

Persistent complainants (distinguished by their pursuit of vindication and retribution) consumed time and resources and resorted to both direct and veiled threats. Attempts to distinguish these people from a control group on the basis of the manner in which their claims were initially managed failed.

Persistent complainants' pursuit of vindication and retribution fits badly with complaints systems established to deliver reparation and compensation. These complainants damaged the financial and social fabric of their own lives and frightened those dealing with their claims. The study suggests methods of early detection and alternative management strategies.