This issue features major papers on bipolar disorder, and further groups of papers on suicide attempts, tobacco smoking, and effects of trauma.

This issue features groups of papers on somatization, neuropsychological function in ecstasy users and in schizophreniform disorder, early psychosis and its treatment, depression and suicide.

This issue features an Invited Review on birth cohort studies in psychiatry, and original articles reporting major follow-up studies of psychiatric disorder, studies of depression, genetic studies, factors associated with disorder in the community, and neuropsychology of schizophrenia.

This issue features groups of papers on theory of mind and schizophrenia, other aspects of schizophrenia, gender and depression, psychoimmunology, antecedents of somatic and psychiatric illness.

This issue features groups of papers reporting controlled trials, depression assessment and biological aspects, and disorders in the elderly. The lead editorial reviews recent studies of the effects on cognition of tryptophan depletion, an important probe of serotonin function.

This issue features groups of papers on functional neuroimaging, epidemiology, depression in the elderly, follow-up studies of psychological therapies, neuropsychology of psychiatric disorders, psychiatry of primary care. An additional paper describes racial differences in the treatment received for psychosis.

This issue features several papers reporting controlled treatment trials and further groups of papers on epidemiology, eating disorders, and depression.

This issue features a review of the cognitive deficits in schizophrenia, and papers on other aspects of schizophrenia, the impact of SARS, trauma and PTSD, genetic and environmental causation in substance use, panic disorder and gambling, the role of cytokines in sickness behaviour, depression, developmental and intellectual disorders.

From the outset, people have had high expectations of functional neuroimaging. Many will have been disappointed. After roughly a decade of widespread use, even an enthusiastic advocate must be diffident about the impact of the two most frequently used techniques – positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) – upon clinical psychiatry. Perhaps this disappointment arises from an unrealistic expectation of what these techniques are able to tell us about the workings of the normal and the disordered brain. Anyone who hoped for intricate and unambiguous region-to-function mapping was always going to be disappointed. This expectation presupposes, among other things, a thorough understanding of the cognitive functions that are to be mapped onto the brain regions. This understanding, however, while developing, is still rudimentary. Mapping disorder along comparable lines is even more complex since it demands two levels of understanding. The first is of the healthy region-to-function mapping, the second of the disordered region-to-function mapping, which immediately demands a consideration of the nature of the function in the disordered state. After all, someone with schizophrenia, when confronted with a psychological task, might tackle it in a very different way, in terms of the cognitive strategies used, from a healthy person confronted with the same task. The observation that brain activity differs across the two individuals would only be interpretable insofar as one thoroughly understood the processes that each individual invoked in response to the task demands.

Countless cross-sectional surveys of primary and secondary care have demonstrated the ubiquitous nature of medically unexplained symptoms. If grouping diverse symptoms under one heading is appropriate, they account for over half of all new presentations in secondary medical care (Nimnuan et al. 2001a) and a sizeable proportion of ‘frequent attenders’ in secondary care have predominantly medically unexplained symptoms (Fink, 1992a; Reid et al. 2002). Such symptoms are costly, persistent, and associated with significant disability and psychiatric disorder (Reid et al. 2001, 2003), but are generally ignored by mental health services (Bass et al. 2001).

Goodwin (2000) famously argued that bipolar disorder was the Cinderella of psychiatry. It certainly should not be: there is no doubt of the anguish caused by the condition, in particular the excess of natural mortality and the great excess of death by suicide (Ösby et al. 2001). In this issue, Mitchell et al. (2004) report that 26% of their cases of bipolar disorder had attempted suicide at some point. This reflects the sheer persistence of personal suffering: Judd and colleagues (2002, 2003) demonstrated in a long and detailed follow-up that patients with bipolar disorder were symptomatic at least half the time. The Australian National Survey of Psychotic Disorders found levels of disability in affective psychosis equal to those of schizophrenia (Jablensky et al. 2000), and bipolar cases are more likely to score highly on measures of disability than unipolar cases (Mitchell et al. 2004). People with bipolar disorder are more likely to be single, widowed or divorced than both the general populace and those with unipolar depression (Mitchell et al. 2004).

We suspect that people have an everyday theory of mind because they explain and frequently talk about the behaviour of others and themselves in terms of beliefs and desires. Having a theory of mind means that we believe that other people have minds like ours and that we understand the behaviour of these others in terms of the contents of their minds: their knowledge, beliefs and desires. But how can we demonstrate experimentally that people are using their theory of mind to predict the behaviour of others. This problem is particularly acute in the case of animals or young human children when they do not have language. Dennett (1978) discussing Premack & Woodruff's (1978) seminal paper ‘Does the chimpanzee have a theory of mind?’, suggested that the use of false beliefs to explain behaviour would provide convincing evidence. When their belief is true (i.e. corresponds to the actual state of the world) we can explain peoples' behaviour on the basis of the state of the world without needing to know about their beliefs. This ambiguity does not arise when the belief is false. The first experiment to use this approach was published by Wimmer & Perner (1983). They showed that at around 4 years of age a child knows that Maxi will look for his chocolates where Maxi believes them to be, even though the child knows that this belief is false because he has seen Maxi's mother moving the chocolates. In the English-speaking world the task involving Maxi and the chocolates has become the Sally-Anne task (see this issue, Lee et al. 2004).

Serotonin (5-hydroxytryptamine, 5-HT) is known to play a role in a wide variety of functions including: mood, anxiety, sleep, aggression, sexual function and cognitive function. In the past decade, the sudden interest in acute amino acid depletion paradigms has stimulated the interest in studying the function of 5-HT in man in vivo. In particular, investigating the association of experimentally lowered 5-HT with cognition by measuring the influence of acute tryptophan depletion (ATD) on performance, and in some cases applying ATD as a challenge test using cognition as disease surrogate marker, have recently become popular. The crucial questions, ‘what can this method tell us about cognitive function in health and disease?’ and ‘what can ATD-induced cognitive changes tell us about health and disease?’ can only be answered after first considering basic assumptions about the method. These pertain to the derived questions, ‘is ATD a serotonergic manipulation?’, ‘is the placebo used in ATD an inactive treatment?’. Also, ‘are there specific cognitive markers of ATD?’. After a brief consideration of these issues, we will focus on the more clinical issues addressing the question whether ATD can be used as a challenge test, to indicate serotonergic vulnerability, using cognitive functions as surrogate measures of disease in particular.

Cognitive psychology became an important discipline in schizophrenia research when information processing deficits were implicated as the basis from which psychotic symptoms emerged (Broen & Storms, 1967; Hemsley, 1977; Frith, 1979). The study of cognition as an independent construct began in earnest when the detection of brain morphological abnormalities on computed tomography (CT) in patients with schizophrenia (Johnstone et al. 1976; Weinberger et al. 1979) prompted the search for behavioural correlates. It became apparent that impairments typical of damage to frontal or medial temporal lobes could be seen in patients with schizophrenia, irrespective of symptom type or severity (Goldberg et al. 1988; McKenna et al. 1990). Since then a number of findings have been replicated sufficiently to make certain conclusions about the nature and extent of cognitive dysfunction in this disorder.

Background. Although the burden of emotional disorders is very high, mental health care is only available to a minority of patients. The literature suggests that self-help strategies, both bibliotherapy and self-help groups alike, are effective for various, less serious complaints but it is unclear whether available data support a role for self-help in treatment protocols for patients with clinically significant emotional disorders.

Method. We searched the literature with a focus on ‘anxiety’ and/or ‘depressive disorder’. Standardized assessment of diagnosis or symptoms and randomized controlled trials were inclusion criteria for a meta-analysis.

Results. The mean effect size of self-help (mainly bibliotherapy) v. control conditions is 0·84, and 0·76 for follow-up; the effect sizes of self-help v. treatment are −0·03 and −0·07 respectively. A longer treatment period is more effective.

Conclusions. Bibliotherapy for clinically significant emotional disorders is more effective than waiting list or no treatment conditions. The dearth of studies on self-help groups for emotional disorders does not permit an evidence-based conclusion concerning the effects of self-help groups. No difference was found between bibliotherapy and psychiatric treatment of relatively short duration.

Longitudinal formulations of psychiatric illness have long been familiar. In the 19th century, Thomas Clouston wrote about developmental insanity in young men, presaging modern views of schizophrenia as having some of its origins or first manifestations in early life (Clouston, 1891; O'Connell et al. 1997). At the same time, Sigmund Freud was creating his system of psychoanalysis to understand hysterical conversion and other aspects of adult psychology as sequelae of early psychological events. Now, within an epidemiological and neuroscientific framework, we are beginning to understand that a variety of psychiatric disorders, including those of later life, such as cognitive decline and dementia may be the final common pathway of a long chain of mutable events (Richards et al. 2004). Just as in clinical neurology, where one is taught to place the causal lesion as high as possible so, too, in psychiatry we should look for the seeds of causality earlier rather than later in life.

Background. Somatoform disorders may have their roots in childhood through processes that involve an enhanced parental focus on health. The aim of this study was to test the hypothesis that somatizing mothers will show less joint involvement than other mothers during play but greater responsiveness when this play involves a ‘medical’ theme.

Method. Cross-sectional observational study of 42 chronic somatizers, 44 organically ill and 50 healthy mothers and their 4–8 year-old children during structured play and a meal. Tasks comprised boxes containing tea-set items, ‘medical’ items and a light snack.

Results. Somatizing mothers were emotionally flatter and showed lower rates of joint attention than other mothers during both play tasks. While the three groups had similar rate of bids for attention, somatizing mothers were more responsive to their child's bids during play with the medical box than at other times. In contrast, the children of somatizing mothers ignored a greater proportion of their mother's bids during play with the medical box than did children of other mothers or during play with a non-medical theme.

Conclusion. The study has demonstrated tentative evidence in support of the hypothesis.

Background. The demand for time-consuming psychotherapy of phobia/panic exceeds the supply of trained therapists. Delegating routine therapy aspects to a computer might ease this problem.

Method. Ninety-three out-patients with phobia or panic disorder were randomized in a 2[ratio ]2[ratio ]1 ratio to have self-exposure therapy guided either mainly by a stand-alone computer system (FearFighter) or entirely face-to-face by a clinician, or to have mainly computer-guided self-relaxation as a placebo. Both computer groups (FearFighter and relaxation) had brief back-up advice from a clinician. Primary outcome measures were self- and blind-assessor ratings of Main Problem and Goals, and Global Phobia.

Results. Drop-outs occurred significantly more often in the two self-exposure groups (43% if mainly computer-guided, 24% if entirely clinician-guided) than with self-relaxation (6%); the difference between the two self-exposure groups was not significant. Even with all drop-outs included, the mainly computer-guided exposure group and the relaxation group had 73% less clinician time per patient than did the entirely clinician-guided exposure group. The two self-exposure groups had comparable improvement and satisfaction at post-treatment and at 1-month follow-up, while relaxation was ineffective. Mean improvement on the primary outcome measures (self- and assessor-rated) was 46% computer, 49% clinician, 9% relaxation at post-treatment (week 10) and 58% computer, 53% clinician and −4% relaxation at 1-month follow-up (week 14). Mean effect sizes on the primary outcome measures were 2·9 computer, 3·5 clinician and 0·5 relaxation at post-treatment; and 3·7 computer, 3·5 clinician and 0·5 relaxation at 1-month follow-up. The assessor did not rate patients at follow-up.

Conclusions. Despite its (non-significantly) higher dropout rate, self-exposure therapy for panic/phobia cut clinician time per patient by 73% without losing efficacy when guided mainly by a computer rather than entirely by a clinician. The finding needs confirmation at a follow-up that is longer and includes a blind assessor. Self-relaxation had the highest rate of completers but was ineffective.

Background. Data on the efficacy and safety of methylphenidate in adults with attention deficit/hyperactivity disorder (ADHD) are lacking in Europe. This study was undertaken to report on the efficacy and safety of methylphenidate in an adult out-patient population with ADHD, and to compare results with US data.

Method. A double-blind randomized cross-over trial comparing methylphenidate and placebo in 45 adults with ADHD with childhood onset was performed in a dose–titration design. Methylphenidate was titrated from 0·5 mg/kg per day in week 1 up to 1·0 mg/kg per day in week 3.

Results. Response rates using methylphenidate varied between 38 and 51%, and using placebo between 7 and 18% (p<0·05), depending on outcome measure used. Although the overall percentage of subjects having any side effect on both methylphenidate and placebo was rather high, side effects on methylphenidate over and above those on placebo were few and mild.

Conclusions. Methylphenidate proves to be an effective and well tolerated treatment for symptoms of ADHD in adults in the short term. Future research should study the long-term response and clarify the impact of gender, co-morbidity, socio-economic status and IQ on response rates in adults with ADHD.

Background. A better understanding of the neural basis of social cognition including mindreading (or theory of mind) and empathy might help to explain some deficits in social functioning in people with schizophrenia. Our aim was to review neuroimaging and neuropsychological studies on social cognition, as they may shed light on the neural mechanisms of social cognition and its dysfunction in patients with schizophrenia.

Method. A selective literature review was undertaken.

Results. Neuroimaging and neuropsychological studies suggest convergence upon specific networks for mindreading and empathy (the temporal cortex, amygdala and the prefrontal cortex). The frontal lobe is likely to play a central role in enabling social cognition, but mindreading and empathic abilities may require relatively different weighting of subcomponents within the same frontal-temporal social cognition network.

Conclusions. Disturbances in social cognition may represent an abnormal interaction between frontal lobe and its functionally connected cortical and subcortical areas. Future studies should seek to explore the heterogeneity of social dysfunction within schizophrenia.