This issue contains two review articles, sets of papers examining various aspects of schizophrenia, dementia and cognitive impairment and eating disorders, and individual articles examining verbal intelligence and therapy outcomes.

This issue contains two invited reviews, sets of papers examining various aspects of depression, anxiety disorders, and trauma/stress exposure and individual articles examining suicide, development of psychosis, and measurement of spirituality.

This issue contains one review article with sets of papers examining various aspects of depression and physical illness, bipolar disorder, and schizophrenia, and four individual articles examining a variety of topics.

This issue contains two reviews, one on the findings from high-risk studies of schizophrenia, and one comparing two psychological interventions for post-traumatic stress disorder (PTSD). Other sets of papers examine various aspects of PTSD, psychosis, personality disorder, and common mental disorders, and four individual papers examine a variety of topics.

This issue's major focus includes two different groups of reviews and articles on the topics of suicide and ADHD. This issue also contains several articles examining various aspects of psychosis.

This issue contains three reviews, one on SSRI use in late pregnancy, one on dimensional approaches to psychiatric diagnoses, and one on resource utilization in the short-term management of deliberate self-harm (DSH). Other sets of papers examine various aspects of substance use and dependence, depression, and suicide, and two individual papers examine further topics.

This issue contains two reviews, one on the aetiology of depression and one on outcome studies of first-episode psychosis. Other sets of papers examine further aspects of depression and psychosis, and four individual papers examine a variety of topics.

This issue contains a review on child-onset bipolar disorder. Other sets of papers examine various aspects of bipolar disorder, depression and suicide, anxiety, and chronic fatigue, and four individual papers examine a variety of topics.

This issue contains two reviews on cognitive reserve and decline, and five further papers examine various aspects of cognition and psychiatric disorder. Three papers focus on aspects of depression, and three individual papers examine a variety of topics.

This issue contains one review article on multi-symptom conditions in Gulf War veterans with sets of papers examining various aspects of psychosis, depression, pervasive developmental disorders, and four individual articles examining a variety of topics.

This issue's major focus is a group of reports on the treatment of depression. In addition there are a combination reports on a range of topics including self-harm, racial and ethnic differences in psychiatric disorders, a new diagnostic psychosis interview scale, PTSD, anxiety disorders, substance abuse and bulimia nervosa.

This issue contains two reviews, one on chronic fatigue syndrome and one on suicide and the menstrual cycle. Other sets of papers examine various aspects of suicide, addictive behaviours, and depression, and three individual papers examine a variety of topics.

Background. According to the self-medication hypothesis, schizophrenia patients would abuse psychoactive substances to get a relief from their negative symptoms. Studies testing the self-medication hypothesis in dual diagnosis (DD) schizophrenia have not been conclusive, with some studies showing that DD patients experience fewer negative symptoms, whereas other studies have failed to detect such differences. One potential confounding factor for this discrepancy lies in the diverse scales used to evaluate the negative symptoms. A systematic quantitative review of the literature using computerized search engines has been undertaken.

Method. Studies were retained in the analysis if: (i) they assessed negative symptoms using the SANS; (ii) groups of schizophrenia patients were divided according to substance use disorders (alcohol, amphetamines, cannabis, cocaine, hallucinogens, heroin and phencyclidine).

Results. Attainable published studies were screened. According to our inclusion criteria, 18 possible studies emerged. Data from 11 studies were available for mathematical analysis. A moderate effect size (total n=1135, 451 DD, 684 single diagnosis, adjusted Hedges' g=–0·470, p=0·00001) was obtained, within a random-effect model, suggesting that DD patients experience fewer negative symptoms. Groups did not differ in age, sex, and positive/general psychopathology.

Conclusions. Using narrow criteria (e.g. SANS), the results of this meta-analysis show that schizophrenia patients with a substance use disorder experience fewer negative symptoms than abstinent schizophrenia patients. As such, these results suggest either that substance abuse relieves the negative symptoms of schizophrenia or that the patients with fewer negative symptoms would be more prone to substance use disorders.

Much of the burden of depression and anxiety in the population is attributable to subclinical symptoms. Broadening formal health-care systems to treat subclinical depression and anxiety is not the answer to reducing this burden, because health-care systems lack the resources even to provide optimal care to clinical cases. The solution proposed is the population-wide dissemination of informal self-help strategies that have evidence for effectiveness. These are highly acceptable to the public, easily applied, inexpensive and may avert the development of many clinical cases.

Background. Gulf War veterans have a number of health complaints. We therefore decided to carry out a systematic review to identify and summarize the findings from studies that have assessed multi-symptom conditions in Gulf War veterans and in an unexposed comparison group.

Method. Studies published between January 1990 and May 2004 were identified by searching a large number of electronic databases. Reference lists and websites were also searched and key researchers were contacted. Studies were included if they compared the prevalence of chronic fatigue syndrome, multiple chemical sensitivity, CDC-defined chronic multi-symptom illness, fibromyalgia, or symptoms of either fatigue or numbness and tingling in Gulf War veterans and non-Gulf veterans. A total of 2401 abstracts were independently reviewed by two authors.

Results. Twenty-three publications fulfilled the inclusion criteria. Gulf deployment was most strongly associated with chronic fatigue syndrome (OR 3·8, 95% CI 2·2–6·7). Gulf War veterans were also approximately three and a half times more likely than non-Gulf veterans to report multiple chemical sensitivity or chronic multi-symptom illness as defined by CDC. The methodological quality of the studies varied but the later and larger studies were of a high methodological standard with robust sampling strategies, adequate response rates and good adjustment for confounders.

Conclusions. The results support the hypothesis that deployment to the Gulf War is associated with greater reporting of multi-symptom conditions.

Depression is well recognized to be rooted in the down-regulation of positive affect systems. This paper reviews some of the social and non-social theories that seek to explain the potential adaptive advantages of being able to tone down positive affect, and how dysfunctions in such affect control can occur in some contexts. Common to most evolutionary theories of depression is the view that loss of control over aversive events and/or major resources/rewards exert downward pressure on positive affect. Social theories, however, suggest that it is loss of control over the social environment that is particularly depressogenic. Two evolutionary theories (the attachment-loss, and the defeat-loss theories) are briefly reviewed and their interaction considered. It is suggested that phenotypes for toning down positive affect, in the face of loss of control, may become more severe in the context of socially hostile, unsupportive and/or excessively competitive environments. The paper briefly considers how human competencies for self-evaluation in relation to others, rumination, self-criticism, and modern social contexts can accentuate dysfunctional expressions of affect regulation.

Background. In schizophrenia research, ‘high risk’ traditionally referred to studies of the offspring of schizophrenic parents at genetically enhanced risk of illness development. Sixteen major high-risk studies have been undertaken although only six followed through to formal illness so data on prediction remain weak. Recently, ‘high risk’ has widened to encompass individuals considered ‘at risk’ by having ‘high risk mental states’, regardless of family history, in whom initiation of early treatment is postulated to improve outcome.

Method. The major familial high-risk studies are reviewed from the perspective of the Edinburgh High Risk Study of Schizophrenia (EHRS), with emphasis on prediction.

Results. Familial high-risk studies have established multiple biological markers, the most reproducible of which relate to neuromotor development and cognition, especially aspects of memory/learning. Although most are probably not specific, they support a neurodevelopmental hypothesis. Family and environmental variables point largely to secondary or indirect associations. Pre-illness, non-specific affective symptomatology may be of greater predictive power than most psychotic phenomena.

Conclusions. Traditional high-risk designs embody many problems but are able to distinguish non-specific markers from illness predictors, and are ideally suited to exploring the evolution of schizophrenia both clinically and biologically (especially with imaging techniques). The EHRS supports the view that greater specificity may accrue to cognitive domains as precursors of predictive utility.

This issue is my last as editor of Psychological Medicine. It is time to wrap up and to say thank you.

Background. The diagnosis of bipolar disorder in pre-pubertal populations remains difficult and often controversial. Consequently, the clinical and neuropsychological characteristics of mania in the child and adolescent years remain poorly defined. This review provides a clinical account of childhood and adolescent bipolar disorder and compares the neuropsychology and neuroanatomy of young BPD patients compared with adult BPD and childhood syndromes of attention deficit hyperactivity disorder (ADHD) and conduct disorder (CD).

Method. Literature review based on Pubmed searches.

Results. Early- and adult-onset mania and BPD may share a common pattern of neurobiological characteristics despite developmental variations in the clinical presentation. In contrast, important distinctions are apparent between the child-onset syndromes of BPD, ADHD and CD, specifically at the neural level.

Conclusions. Disorders of affect dysregulation in childhood deserve closer neuroscientific and phenotypic scrutiny than given hitherto.

Background. The idea that superior cognitive function acts as a protective factor against dementia and the consequences of head injury is well established. Here we suggest the hypothesis that cognitive reserve is also important in neuropsychiatric disorders including schizophrenia, bipolar disorder and depression.

Method. We review the history of passive and active models of reserve, and apply the concept to neuropsychiatric disorders. Schizophrenia is used as an exemplar because the effects of premorbid IQ and cognitive function in this disorder have been extensively studied.

Results. Cognitive reserve may impact on neuropsychiatric disorders in three ways: by affecting the risk for developing the disorder, in the expression of symptoms within disorders, and in patients' functional outcome. Cognitive failure below a certain threshold may alone, or in combination with common psychiatric symptoms, produce neuropsychiatric syndromes.

Conclusions. Consideration of cognitive reserve may considerably improve our understanding of individual differences in the causes and consequences of neuropsychiatric disorders. For these reasons, the concept of cognitive reserve should be incorporated in future studies of neuropsychiatric disorder. It may be possible to enhance cognitive reserve through pharmacological or non-pharmacological means, such as education, neurocognitive activation or other treatment programmes.