Background. The incidence of schizophrenia in the African-Caribbean population in England is reported to be raised. We sought to clarify whether (a) the rates of other psychotic disorders are increased, (b) whether psychosis is increased in other ethnic minority groups, and (c) whether particular age or gender groups are especially at risk.

Method. We identified all people (n=568) aged 16–64 years presenting to secondary services with their first psychotic symptoms in three well-defined English areas (over a 2-year period in Southeast London and Nottingham and a 9-month period in Bristol). Standardized incidence rates and incidence rate ratios (IRR) for all major psychosis syndromes for all main ethnic groups were calculated.

Results. We found remarkably high IRRs for both schizophrenia and manic psychosis in both African-Caribbeans (schizophrenia 9·1, manic psychosis 8·0) and Black Africans (schizophrenia 5·8, manic psychosis 6·2) in men and women. IRRs in other ethnic minority groups were modestly increased as were rates for depressive psychosis and other psychoses in all minority groups. These raised rates were evident in all age groups in our study.

Conclusions. Ethnic minority groups are at increased risk for all psychotic illnesses but African-Caribbeans and Black Africans appear to be at especially high risk for both schizophrenia and mania. These findings suggest that (a) either additional risk factors are operating in African-Caribbeans and Black Africans or that these factors are particularly prevalent in these groups, and that (b) such factors increase risk for schizophrenia and mania in these groups.

Background. Despite an abundance of clinical research on premenstrual and menstrual symptoms, few epidemiological data provide estimates of the prevalence, incidence, co-morbidity, stability and correlates of premenstrual dysphoric disorder (PMDD) in the community.

Aims. To describe the prevalence, incidence, 12 co-morbidity factors and correlates of threshold and subthreshold PMDD in a community sample of young women.

Methods. Findings are based on prospective–longitudinal community survey of 1488 women aged 14–24, who were followed-up over a period of 48 months (follow-up, N = 1251) as part of the EDSP sample. Diagnostic assessments were based on the Composite International Diagnostic Interview (CIDI) and its 12-month PMDD diagnostic module administered by clinical interviewers. Diagnoses were calculated using DSM-IV algorithms, but daily ratings of symptoms, as required, were not available.

Results. The baseline 12-month prevalence of DSM-IV PMDD was 5·8%. Application of the diagnostic exclusion rules with regard to concurrent major depression and dysthymia decreased the rate only slightly (5·3%). An additional 18·6% were ‘near-threshold’ cases, mostly because they failed to meet the mandatory impairment criterion. Over the follow-up period only few new PMDD cases were observed: cumulative lifetime incidence was 7·4%. PMDD syndrome was stable across 48 months with <10% complete remissions among baseline PMDD cases. The 12-month and lifetime co-morbidity rates were high (anxiety disorders 47·4%, mood disorders 22·9%; somatoform 28·4%), only 26·5% had no other mental disorder. Particularly high odds ratios were found with nicotine dependence and PTSD. In terms of correlates increased rates of 4-weeks impairment days, high use of general health and mental health services, and increased rates of suicide attempts were found.

Conclusion. In this sample of adolescents and young adults, premenstrual symptoms were widespread. However, DSM-IV PMDD was considerably less prevalent. PMDD is a relatively stable and impairing condition, with high rates of health service utilization, increased suicidality and substantial co-morbidity.

In a sample of chronic schizophrenic patients, a group of symptoms which included poverty of speech and lack of spontaneous movement was found to be associated with poor performance in tests of conceptual thinking, object naming and long-term memory, and also with cortical neurological signs. A second group of symptoms which included formal thought disorder and inappropriate affect was associated with poor performance in tests of concentration, immediate recall and word learning, and with cortical neurological signs. The findings suggest that these two syndromes are associated with dysfunction at two different sites within the frontal lobes. A third group of symptoms, comprising various delusions and hallucinations, was associated with poor figure-ground perception, and might reflect temporal lobe dysfunction.

Background. Data are presented on the general population epidemiology of DSM-III-R bipolar I disorder in the United States.

Methods. Data come from the US National Comorbidity Survey (NCS), a general population survey of DSM-III-R disorders. A modified version of the Composite International Diagnostic Interview was used to make diagnoses.

Results. A small (N=59) clinical reappraisal study showed that the only manic symptom profile that could validly be assessed with the CIDI is characterized by euphoria, grandiosity and the ability to maintain energy without sleep, which described approximately half of all clinically validated bipolar I cases in the NCS. Further analysis focused on this symptom profile, which involved N=29 cases in the total sample. Lifetime prevalence was estimated to be 0·4% and 12-month prevalence only slightly lower. Caseness was negatively related to income, education and age, positively related to urbanicity, and elevated among the previously married, never married and non-whites. All cases reported at least one other NCS/DSM-III-R disorder and 59·3% reported that their episode of bipolar disorder (either mania or depression) occurred at a later age than at least one other NCS/DSM-III-R disorder. Although 93·2% of lifetime cases reported some lifetime treatment, only 44·7% of recent cases were in treatment.

Conclusions. The type of bipolar disorder examined here is highly chronic, co-morbid and impairing. Increased efforts are required to attract current cases into appropriate treatment. Methodological research is needed to develop more accurate measures of other bipolar symptom profiles for use in general population epidemiological studies.

Background. We have developed the Major Depression Inventory (MDI), consisting of 10 items, covering the DSM-IV as well as the ICD-10 symptoms of depressive illness. We aimed to evaluate this as a scale measuring severity of depressive states with reference to both internal and external validity.

Method. Patients representing the score range from no depression to marked depression on the Hamilton Depression Scale (HAM-D) completed the MDI. Both classical and modern psychometric methods were applied for the evaluation of validity, including the Rasch analysis.

Results. In total, 91 patients were included. The results showed that the MDI had an adequate internal validity in being a unidimensional scale (the total score an appropriate or sufficient statistic). The external validity of the MDI was also confirmed as the total score of the MDI correlated significantly with the HAM-D (Pearson's coefficient 0·86, P[les ]0·01, Spearman 0·80, P[les ]0·01).

Conclusion. When used in a sample of patients with different states of depression the MDI has an adequate internal and external validity.

A two-stage psychiatric survey of a random sample of adults aged 18–64 from Camberwell is described. Agency interviewers carried out the first stage (N = 800), using the shorter form of the Present State Examination (PSE). MRC interviewers, using the full PSE, saw a stratified sample of these (N = 310) in the second stage. A second interview was sought with all those of Index of Definition (ID) level 5 and above at the first interview (‘cases’) and with a random sample of those below that level. 20·9% refused or were never available for the first interview. Of the 800 subjects successfully interviewed, 10% refused a further interview and 12·4% of those finally selected for this interview were either unavailable or changed their minds. The MRC data, weighted to represent the whole sample, are used in our analyses. The prevalence of psychiatric disorder as defined in our study was calculated at 6·1% for men and 14·9% for women. Women shared a higher prevalence of disorder in the age-groups 25–34 and 45–54, but in men there was no significant association with age.

In contrast to the findings of Brown & Harris (1978), social class did not have a strong association with disorder. Single men had much higher rates than married men, while the reverse was true in women. In both sexes employment was associated with lower rates of disorder. An attempt to explain the high prevalence in women in terms of their role in marriage and child-care was only partly successful.

There is evidence that 3.17% of women report post-traumatic stress disorder (PTSD) after childbirth. This meta-analysis synthesizes research on vulnerability and risk factors for birth-related PTSD and refines a diathesis–stress model of its aetiology. Systematic searches were carried out on PsycINFO, PubMed, Scopus and Web of Science using PTSD terms crossed with childbirth terms. Studies were included if they reported primary research that examined factors associated with birth-related PTSD measured at least 1 month after birth. In all, 50 studies (n = 21 429) from 15 countries fulfilled inclusion criteria. Pre-birth vulnerability factors most strongly associated with PTSD were depression in pregnancy (r = 0.51), fear of childbirth (r = 0.41), poor health or complications in pregnancy (r = 0.38), and a history of PTSD (r = 0.39) and counselling for pregnancy or birth (r = 0.32). Risk factors in birth most strongly associated with PTSD were negative subjective birth experiences (r = 0.59), having an operative birth (assisted vaginal or caesarean, r = 0.48), lack of support (r = −0.38) and dissociation (r = 0.32). After birth, PTSD was associated with poor coping and stress (r = 0.30), and was highly co-morbid with depression (r = 0.60). Moderator analyses showed that the effect of poor health or complications in pregnancy was more apparent in high-risk samples. The results of this meta-analysis are used to update a diathesis–stress model of the aetiology of postpartum PTSD and can be used to inform screening, prevention and intervention in maternity care.

The reliability and validity of the Visual Analogue Mood Scale (VAMS) has been demonstrated in both a military and a private psychiatric hospital, inpatient population. The repeated and concurrent administration of the VAMS and the Digit-Symbol test identifies a mood-performance correlation which distinguishes patients with affective disorders, of manic or depressed type, from other psychiatric patients.

This essay explores four answers to the question ‘What kinds of things are psychiatric disorders?’ Essentialist kinds are classes whose members share an essence from which their defining features arise. Although elegant and appropriate for some physical (e.g. atomic elements) and medical (e.g. Mendelian disorders) phenomena, this model is inappropriate for psychiatric disorders, which are multi-factorial and ‘fuzzy’. Socially constructed kinds are classes whose members are defined by the cultural context in which they arise. This model excludes the importance of shared physiological mechanisms by which the same disorder could be identified across different cultures. Advocates of practical kinds put off metaphysical questions about ‘reality’ and focus on defining classes that are useful. Practical kinds models for psychiatric disorders, implicit in the DSM nosologies, do not require that diagnoses be grounded in shared causal processes. If psychiatry seeks to tie disorders to etiology and underlying mechanisms, a model first proposed for biological species, mechanistic property cluster (MPC) kinds, can provide a useful framework. MPC kinds are defined not in terms of essences but in terms of complex, mutually reinforcing networks of causal mechanisms. We argue that psychiatric disorders are objectively grounded features of the causal structure of the mind/brain. MPC kinds are fuzzy sets defined by mechanisms at multiple levels that act and interact to produce the key features of the kind. Like species, psychiatric disorders are populations with central paradigmatic and more marginal members. The MPC view is the best current answer to ‘What kinds of things are psychiatric disorders?’

The network approach to psychopathology posits that mental disorders can be conceptualized and studied as causal systems of mutually reinforcing symptoms. This approach, first posited in 2008, has grown substantially over the past decade and is now a full-fledged area of psychiatric research. In this article, we provide an overview and critical analysis of 363 articles produced in the first decade of this research program, with a focus on key theoretical, methodological, and empirical contributions. In addition, we turn our attention to the next decade of the network approach and propose critical avenues for future research in each of these domains. We argue that this program of research will be best served by working toward two overarching aims: (a) the identification of robust empirical phenomena and (b) the development of formal theories that can explain those phenomena. We recommend specific steps forward within this broad framework and argue that these steps are necessary if the network approach is to develop into a progressive program of research capable of producing a cumulative body of knowledge about how specific mental disorders operate as causal systems.

Exercise can improve clinical outcomes in people with severe mental illness (SMI). However, this population typically engages in low levels of physical activity with poor adherence to exercise interventions. Understanding the motivating factors and barriers towards exercise for people with SMI would help to maximize exercise participation. A search of major electronic databases was conducted from inception until May 2016. Quantitative studies providing proportional data on the motivating factors and/or barriers towards exercise among patients with SMI were eligible. Random-effects meta-analyses were undertaken to calculate proportional data and 95% confidence intervals (CI) for motivating factors and barriers toward exercise. From 1468 studies, 12 independent studies of 6431 psychiatric patients were eligible for inclusion. Meta-analyses showed that 91% of people with SMI endorsed ‘improving health’ as a reason for exercise (N = 6, n = 790, 95% CI 80–94). Among specific aspects of health and well-being, the most common motivations were ‘losing weight’ (83% of patients), ‘improving mood’ (81%) and ‘reducing stress’ (78%). However, low mood and stress were also identified as the most prevalent barriers towards exercise (61% of patients), followed by ‘lack of support’ (50%). Many of the desirable outcomes of exercise for people with SMI, such as mood improvement, stress reduction and increased energy, are inversely related to the barriers of depression, stress and fatigue which frequently restrict their participation in exercise. Providing patients with professional support to identify and achieve their exercise goals may enable them to overcome psychological barriers, and maintain motivation towards regular physical activity.

Background. Several theoretical explanations of ADHD in children have focused on executive functioning as the main explanatory neuropsychological domain for the disorder. In order to establish if these theoretical accounts are supported by research data for adults with ADHD, we compared neuropsychological executive functioning and non-executive functioning between adults with ADHD and normal controls in a meta-analytic design.

Method. We compared 13 studies that (1) included at least one executive functioning measure, (2) compared the performance of an adult ADHD group with that of an adult normal control group, (3) provided sufficient information for calculation of effect sizes, and (4) used DSM-III-R or DSM-IV criteria to diagnose ADHD.

Results. We found medium effect sizes both in executive functioning areas [verbal fluency (d=0·62), inhibition (d=0·64 and d=0·89), and set shifting (d=0·65)] and in non-executive functioning domains [consistency of response (d=0·57), word reading (d=0·60) and color naming (d=0·62)].

Conclusions. Neuropsychological difficulties in adult ADHD may not be confined to executive functioning. The field is in urgent need of better-designed executive functioning tests, methodological improvements, and direct comparisons with multiple clinical groups to answer questions of specificity.

Taxometric research methods were developed by Paul Meehl and colleagues to distinguish between categorical and dimensional models of latent variables. We have conducted a comprehensive review of published taxometric research that included 177 articles, 311 distinct findings and a combined sample of 533 377 participants. Multilevel logistic regression analyses have examined the methodological and substantive variables associated with taxonic (categorical) findings. Although 38.9% of findings were taxonic, these findings were much less frequent in more recent and methodologically stronger studies, and in those reporting comparative fit indices based on simulated comparison data. When these and other possible confounds were statistically controlled, the true prevalence of taxonic findings was estimated at 14%. The domains of normal personality, mood disorders, anxiety disorders, eating disorders, externalizing disorders, and personality disorders (PDs) other than schizotypal yielded little persuasive evidence of taxa. Promising but still not definitive evidence of psychological taxa was confined to the domains of schizotypy, substance use disorders and autism. This review indicates that most latent variables of interest to psychiatrists and personality and clinical psychologists are dimensional, and that many influential taxonic findings of early taxometric research are likely to be spurious.