To isolate determinants of any female preponderance in depressive disorder, we earlier selected a sample of young adults, then similar in terms of several potential social determinants of depression and with equivalent rates of lifetime depression. We now report a 10-year review, which initially suggested a female preponderance in DIS-generated RDC and DSM-III lifetime depressive categories. The presence of sex differences in rates of lifetime depression was influenced by the definition of caseness used and the vantage point from which rates were determined. The longitudinal design and earlier corroborative witness reports established, however, clear evidence of instability in prevalence estimates, together with a sex effect on stability. Men were more likely to ‘forget’ episodes, while women were more likely to ‘remember’ episodes that had generally not previously reached ‘case’ criteria. When correction was made for such artefactual influences, a sex difference in lifetime depression rates was no longer evident. Such findings require review in general community samples, and suggest modifications to ‘case’ definition in epidemiological enquiries.

Background. We aimed to explore the prevalence and factor structure of premenstrual symptoms in a sample of Australian twins; to investigate phenotypic associations between reported premenstrual symptoms, personality and reproductive dimensions; and to identify the relative contributions of genes and environment to premenstrual symptoms and the extent of genetic and environmental covariation with the personality trait Neuroticism and lifetime major depression.

Method. Seven hundred and twenty female twin pairs (454 monozygotic and 266 dizygotic) from the Australian National Health and Medical Research Council Twin Register reported on experience of 17 premenstrual symptoms during the previous 12 months. In the same questionnaire twins also responded to questions on symptom states, and personality dimensions including neuroticism. Interview data enabling diagnosis of lifetime history of DSM-IV major depression were also available. We fitted univariate and multivariate genetic models to the data.

Results. Most frequently reported symptoms were breast tenderness/pain and bloating/weight gain, followed by affective symptoms. Twelve-month prevalence was 2·4% for the combination of symptoms and functional interference meeting a very rough approximation of DSM-III-R criteria for late luteal dysphoric disorder. Principal factor analysis identified a single premenstrual (PMS) factor. Additive genetic influences (44% of total variance) were identified for PMS. Although we found genetic correlations of 0·62 between reported PMS and neuroticism, and 0·70 with lifetime major depression, 39% of the genetic variance of PMS was not explained by these factors.

Conclusions. Our findings support the existence of genetic influences on premenstrual symptoms, but we were unable to distinguish between liability to symptom experience and symptom reporting. Retrospective reporting may have contributed to our finding that PMS genes were shared in part with neuroticism and liability to lifetime major depression.

Background. The Stirling County Study provides a 40-year perspective on the epidemiology of psychiatric disorders in an adult population in Atlantic Canada. Across samples selected in 1952, 1970 and 1992 current prevalence of depression was stable. This paper concerns time trends in annual incidence as assessed through cohorts selected from the first two samples.

Methods. Consistent interview data were analysed by a computerized diagnostic algorithm. The cohorts consisted of subjects at risk for a first depression: Cohort-1 (N = 575) was followed 1952–1970; Cohort-2 (N = 639) was followed 1970–1992. Life-table methods were used to calculate incidence rates and proportional hazards procedures were used for statistical assessment.

Results. Average annual incidence of depression was 4·5 per 1000 for Cohort-1 and 3·7 for Cohort- 2. Differences by gender, age and time were not statistically significant. The stability of incidence and the similarity of distribution by gender and age in these two cohorts corresponds to findings about the two early samples. In contrast, current prevalence in the recent sample was distributed differently and showed an increase among women under 45 years.

Conclusions. The stability of the incidence of depression emphasizes the distinctive characteristics of current prevalence in the recent sample and suggests that the dominance of women in rates of depression may have occurred among those born after the Second World War. The results offer partial support for the interpretation of an increase in depression based on retrospective data in other recent studies but they indicate that the increase is specific to women.

Background. In many biomedical disorders, early age at onset (AAO) is an index of high liability to illness which is manifest by an increased risk of illness in relatives. Most but not all prior studies report such a pattern for major depression (MD).

Method. Lifetime MD and AAO were assessed at personal interview using modified DSM-III-R criteria in 13864 twin pairs, including 4229 onsets of MD, from the Swedish National Twin Registry. Analyses were conducted using Cox proportional hazards models.

Results. Controlling for year of birth, gender, zygosity, co-twin history of MD and the interaction of zygosity and co-twin history, the best-fit model showed a significant main effect and a quadratic effect of AAO of MD in the co-twin on the log hazard ratio for MD in the index twin. When examined together, these effects predicted that from the ages of 15 to ~35 years, AAO of MD is moderately negatively related to risk of illness in relatives. However, past age 35, the function flattens out, with little change of risk in relatives with further increases of AAO. Even when the co-twin had a late AAO, the risk in the index twin substantially exceeded that seen when the co-twin had no history of MD.

Conclusion. In this large sample, AAO is a meaningful, albeit modest, index of familial liability to MD. The relationship is nonlinear and results largely from an increased liability in individuals with an early AAO. These results should be interpreted in the context of the limitations of long-term recall.

Twenty-six consecutive admissions to an accident and emergency unit with minor head injury were examined. This was defined as a head injury warranting brief in-patient overnight stay but with a post-traumatic amnesia of less than 12 hours. Each patient had a neurological examination, a post-traumatic symptom check list completed, EEG power spectra analysis and auditory brain stem-evoked potential recordings, and a four-choice reaction-time measurement. These assessments were repeated six weeks later. Six months after the head injury a symptom check list was completed and four-choice reaction time measured again. Post-traumatic symptoms are persistent in half of all patients at six weeks and six months follow-up. The EEG power spectra showed a significant change in theta power between the first recording and the second one at six weeks, with relative reduction being noted. Approximately half of all the patients had significant delays in brain stem conduction time at day 0. There was a trend towards a decrease in brain stem conduction time at six weeks, though in almost half the brain stem conduction time still remained abnormal at six weeks. Head-injured patients had prolonged choice reaction times at day 0 with serial improvement between then and six months, though the values at six weeks were still significantly longer than healthy controls. It is suggested that these findings reflect both cortical and brain stem damage following minor head injury, the brain stem damage being more persistent. There appear to be three patterns of recovery, half recovering within six weeks, a minority persisting over six months with persisting brain stem dysfunction and less than a third showing an exacerbation of symptoms with no evidence of brain stem dysfunction, the exacerbation being possibly a consequence of psychological and social factors.

Twenty-three in-patients fulfilling DSM-III-R criteria for major depressive disorder were submitted to a standard cued recall test, and to a word-stem completion test devised to assess the effect of the initial presentation without the explicit retrieval of the words being necessary. Results show that depressed patients are impaired on the cued recall task in comparison with controls matched for sex, age, and educational level. However, the two groups do not differ in the word-stem completion task. This dissociation between explicit and implicit expressions of memory disappeared when patients recovered, although they were still hospitalized and under psychotropic medication. These results are examined in the light of the distinction between effortful and automatic processes.

Background. Despite the demonstrable influence of both genes and the family environment on children's behavioural and emotional development, the mechanisms by which these factors are transmitted from parents to their children are not known. Numerous aspects of the family have long been associated with behavioural and emotional problems in children; it is not clear, however, whether these family variables represent genuine environmental risks or secondary consequences of the underlying genetic liability shared between parents and their children.

Method. In this study we present a model for analysing the non-genetic contributions of family background to risk for childhood and adolescent depression and conduct disturbance using simulated data on adult MZ and DZ twins, their spouses and children.

Results. The twin offspring design provides substantial power to detect remarkably small non-genetic effects on parent–offspring resemblance against the background of genetic transmission. As presented, the model is able to resolve the direction of transmission from both parent to child (passive genotype–environment correlation) and child to parent (evocative genotype–environment correlation).

Conclusions. Unlike many other genetic studies, a study of twins and their children can sort out which putative family environmental risk factors do actually have a significant environmental impact on the child and which ones only appear to do so because they are associated with genetic mediation.

The ecological association between unemployment and parasuicide rates among males in Edinburgh over the period 1968–82 was positive and highly significant (r = 0·77). Similarly, the two rates were found to be correlated across the city wards in 1971 (r = 0·76) and even more strongly in 1981 (r = 0·95). Throughout the period the parasuicide rate among the unemployed was nearly always more than 10 times higher than that among the employed. The long-term unemployed were at much higher risk than those out of work for lesser periods, although the impact of recent job loss was marked. Population attributable risk has shown a tendency to rise in line with the upward trend in the unemployment rate, despite the decline in relative risk over the period. The findings were considered consistent with the view that unemployment increases the parasuicide rate.

Background. A recent US study presented data suggesting that depressed women are more likely to respond to selective serotonin reuptake inhibitor (SSRI) than tricyclic (TCA) antidepressant drug therapies. We have undertaken replication studies in two independent databases.

Method. We have examined for gender differences in SSRI and TCA antidepressant response in both retrospective and prospective naturalistic uncontrolled studies, and in subsets of melancholic and non-melancholic depressed subjects. As the US study had indicated that women under the age of 40 years were particularly likely to show a differential response to SSRIs, we examined for age, gender and interactional effects. In addition, we examined for differential SSRI and TCA responsiveness in a subset of patients who had received drugs from both classes.

Results. We failed to find evidence of women having a preferential response to SSRI medication or, conversely, of men having a superior response to TCA medication. Older age, however, was associated with a superior TCA response and younger age with a superior SSRI response.

Conclusion. As few studies have examined for differential gender and age effects in response to narrow action and broad action antidepressant drugs across major depressive subtypes, gender differential effects remain to be established.

Background. General practitioners are increasingly involved in the care of patients with long-term psychiatric disorders. We have previously reported that general practitioners are less willing to treat patients with schizophrenia than those without such a diagnosis, but this may have been attributable to a reluctance to treat patients with any psychiatric or chronic illness. We, therefore, examined general practitioners' attitudes to patients with chronic psychiatric or medical illnesses.

Methods. A random sample of 260 local general practitioners were each sent one of our case vignettes which were identical apart from mention of a previous diagnosis of schizophrenia, depression, diabetes or no illness. The general practitioners were asked to indicate their level of agreement with 13 attitudinal statements based on the vignette.

Results. One hundred and sixty-six (66%) of the general practitioners responded to the case vignettes. Those responding to the vignette about the patient with schizophrenia were less happy to have that patient on their practice list and were more concerned about the risk of violence and the child's welfare. Those responding to the depression vignette were more likely to offer the patient antidepressants or counselling; and those who replied to the diabetes case were most likely to refer the patient to a hospital specialist. These differences were not attributable to the personal or practice characteristics of the general practitioners.

Conclusions. Patients with schizophrenia arouse concerns in general practitioners that are not simply due to those patients suffering from a psychiatric or chronic illness. Our results suggest that some patients with schizophrenia may find it difficult to register with a general practitioner and receive the integrated community-based health care service they require. Psychiatrists should provide education and support to general practitioners who look after patients with schizophrenia.

The development over the last 60 years of the concept of bradyphrenia, a syndrome including slowing of cognitive processing in parkinsonism, is described. Psychic akinesia and subcortical dementia are seen as more recent synonyms for this syndrome. Its relations to akinesia and the psychomotor retardation of depression are considered in a historical context, as are its implications for the relation of neurological and psychiatric disorder.

Background. A lack of inhibitory control has been suggested to be the core deficit in children with attention deficit hyperactivity disorder (ADHD). This means that a primary deficit in behavioral inhibition mediates a cascade of secondary deficits in other executive functions, such as arousal regulation. Clinical observations have revealed that with increasing age symptoms of hyperactivity and impulsivity decline at a higher rate than those of inattention. This might imply that a deficit in attention rather than a lack of inhibitory control is the major feature in adult ADHD.

Method. To study whether an attentional or inhibitory deficit predominates, the stop-signal task and the stop-change task were presented to 24 adults with ADHD combined subtype and 24 controls.

Results. Relative to controls, the stop-signal reaction time (SSRT) was significantly more prolonged than the go-stimulus reaction time (RT) in patients with ADHD. This disproportionate elongation of the SSRT was comparable across tasks, even though the stop-change task exerted more complex (or at least different) demands on the inhibitory system than the stop-signal task. ADHD patients had a higher proportion of choice errors, possibly reflecting more premature responses. Specifically in the stop-change task, patients had more variable choice responses and made more inappropriate change responses, which may also reflect enhanced impulsivity.

Conclusions. The results support a core deficit in behavioral inhibition in adults with ADHD. We further suggest that there is more evidence for a critical role of deficient inhibitory control in adults than in children with ADHD.