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.

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. Repetitive transcranial magnetic stimulation (rTMS) of frontal brain regions is under study as a non-invasive method in the treatment of affective disorders. Recent publications provide increasing evidence that rTMS may be useful in treating schizophrenia. Results are most intriguing, demonstrating a reduction of negative symptoms following high-frequency rTMS. In this context, disentangling of negative and depressive symptoms is of the utmost importance when understanding specific rTMS effects on schizophrenic symptoms.

Method. Using a sham-controlled parallel design, 20 patients with schizophrenia were included in the study. Patients were treated with high-frequency 10 Hz rTMS over 10 days. Besides clinical ratings, ECD-SPECT (technetium-99 bicisate single photon emission computed tomography) imaging was performed before and after termination of rTMS treatment.

Results. High-frequency rTMS leads to a significant reduction of negative symptoms combined with a trend for non-significant improvement of depressive symptoms in the active stimulated group as compared with the sham stimulated group. Additionally, a trend for worsening of positive symptoms was observed in the actively treated schizophrenic patients. In both groups no changes in regional cerebral blood flow could be detected by ECD-SPECT.

Conclusions. Beneficial effects of high-frequency rTMS on negative and depressive symptoms were found, together with a trend for worsening positive symptoms in schizophrenic patients.

Background. Using the theoretical framework of the Self Regulation Model (SRM), many studies have demonstrated that beliefs individuals hold about their physical health problems are important in predicting health outcomes. This study tested the SRM in the context of a mental health problem, schizophrenia.

Method. One hundred and twenty-four people with a diagnosis of schizophrenia were assessed on measures of symptom severity, beliefs about their mental health problems, coping and appraisal of outcome at two time points, 6 months apart.

Results. Using multivariate analyses and controlling for severity of symptoms, beliefs about mental health were found to be significant predictors of outcome. Beliefs about greater negative consequences were the strongest and most consistent predictors of a poorer outcome in both cross-sectional and longitudinal analyses.

Conclusions. These results suggest that the SRM is a promising model for mental health problems and may highlight important areas for development in clinical, and especially psychosocial interventions.

Background. In order to investigate whether correlated but separable symptom dimensions that have been identified in clinical samples also have a distribution in the general population, the underlying structure of symptoms of depression, mania and psychosis was studied in a general population sample of 7072 individuals.

Method. Data were obtained from the three measurements of the Netherlands Mental Health Survey and Incidence Study (NEMESIS). Symptoms of depression, mania and the positive symptoms of psychosis were assessed using the Composite International Diagnostic Interview. Confirmatory factor-analysis was used to test statistically the fit of hypothesized models of one, two, three or seven dimensions.

Results. The seven-dimensional model comprising core depression, sleep problems, suicidal thoughts, mania, paranoid delusions, first-rank delusions and hallucinations fitted the data best, whereas the unidimensional model obtained the poorest fit. This pattern of results could be replicated at both follow-up measurements. The results were similar for the subsamples with and without a lifetime DSM-III-R diagnosis. The seven dimensions were moderately to strongly correlated, with correlations ranging from 0·18 to 0·73 (mean 0·45).

Conclusions. In the general population, seven correlated but separable dimensions of experiences exist that resemble dimensions of psychopathology seen in clinical samples with severe mental illness. The substantial correlations between these dimensions in clinical and non-clinical samples may suggest that there is aetiological overlap between the different dimensions regardless of level of severity and diagnosable disorder.

Background. Severe acute respiratory syndrome (SARS) is a novel disease. The authors have limited knowledge of its impact on mental health. The present study aimed to examine the level and extent of psychological distress of SARS survivors following 1-month recovery, to explore patients' negative appraisals of the impact of SARS, and to evaluate the associations between psychological distress and negative appraisals.

Method. The Beck Anxiety Inventory, the Beck Depression Inventory, and a newly developed measure, the SARS Impact Scale (SIS), were mailed to 453 Hong Kong Chinese SARS survivors discharged from hospital for 4 weeks or more.

Results. A total of 425 patients received the questionnaires and 180 (mean age 36·9 years; 120 women) gave valid replies. The response rate was 42·4%. The participants also represented 13·6% of all adult survivors in Hong Kong. About 35% of respondents reported ‘moderate to severe’ or ‘severe’ ranges of anxiety and/or depressive symptoms. It was found that those working as healthcare workers or having family members killed by SARS were more prone to develop subsequent high levels of distress. Factor analyses extracted three meaningful factors of the SIS, namely ‘survival threat’, ‘physical impact’, and ‘social impact’. Negative appraisals at the acute phase and 1-month recovery significantly accounted for substantial portions of variances for anxiety and depressive symptoms, after the effects of other psychosocial variables were controlled.

Conclusions. Psychological distress of SARS survivors at 1-month recovery is real and significant. Negative appraisals may play a pivotal role in the development of psychological distress for SARS survivors, at least in the short term.

Background. The outbreak of severe acute respiratory syndrome (SARS) posed an unprecedented threat and a great challenge to health professionals in Hong Kong. The study reported here aimed at investigating the origin of stress and psychological morbidity among frontline healthcare workers in response to this catastrophe.

Method. Self-administered questionnaires were sent to frontline healthcare workers in three hospitals. The General Health Questionnaire was used to identify psychological distress. Sociodemographic and stress variables were entered into a logistic regression analysis to find out the variables associated with psychological morbidity.

Results. The response rate was 40%. Sixty-eight per cent of participants reported a high level of stress. About 57% were found to have experienced psychological distress. The healthcare workers' psychological morbidity was best understood by the perceptions of personal vulnerability, stress and support in the workplace.

Conclusion. These findings shed light on the need for hospital administrators to be aware of the extent and sources of stress and psychological distress among frontline healthcare workers during disease outbreak.

Background. Partial PTSD, employed initially in relation to Vietnam veterans, has been recently extended to civilian victims of trauma. We examined the extent to which partial PTSD is distinguishable from full DSM-PTSD with respect to level of impairment.

Method. A representative sample of 2181 persons was interviewed by telephone to record lifetime traumatic events and to assess DSM-IV PTSD criteria. Partial PTSD was defined as [ges ]1 symptom in each of three symptom groups (criteria B, C and D) and duration of [ges ]1 month. Impairment in persons with PTSD and partial PTSD was measured by number of work-related and personal disability days during the 30-day period when the respondent was most upset by the trauma.

Results. Compared to exposed persons with neither PTSD nor partial PTSD, increment in work-loss days associated with PTSD was 11·4 (S.E.=0·6) days and with partial PTSD, 3·3 (S.E.=0·4) days (adjusted for sex, education and employment). Similar disparities were found across other impairment indicators. Persons who fell short of PTSD criteria by one symptom of avoidance and numbing reported an increment of 5·0 (S.E.=0·7) work-loss days, 6·0 fewer than full PTSD. PTSD was associated with excess impairment, controlling for number of symptoms. A significantly lower proportion of persons with partial PTSD than full PTSD experienced symptoms for more than 2 years. A lower proportion of persons with partial PTSD than full PTSD had an etiologic event of high magnitude.

Conclusions. PTSD identifies the most severe trauma victims, who are markedly distinguishable from victims with subthreshold PTSD.

Background. Counterfactual thinking (CFT) refers to the process of reflecting on an event and changing aspects of it so as to alter the eventual outcome. Such thinking appears frequent in survivors of trauma (e.g. ‘If only I had stayed at home then I wouldn't have had the accident’), but has received little systematic empirical investigation. Four studies examined the nature of CFT in both trauma survivors and non-traumatized controls.

Method. Participants generated CFT to their own trauma or to written scenarios.

Results. Three key findings emerged. Firstly, trauma survivors overwhelmingly produced CFT that mutated aspects of their own behaviour during the traumatic event (self-referent CFT) and that improved the event's outcome (upward CFT; Studies 1 and 2). Secondly, self-referent CFT style in trauma survivors was generalized to non-autobiographical scenarios and was independent of how much control the protagonist in the scenarios had over the outcome. In contrast, never-traumatized controls tended to generate more self-referent CFT to scenarios where the protagonists had some control than to scenarios where the protagonist had little control (Study 3). Thirdly, this self-referent, upward CFT style of trauma survivors was not related to frequency of post-traumatic stress symptoms (Studies 1 and 3) or Posttraumatic Stress Disorder (PTSD) caseness (Study 2).

Conclusions. These results are interpreted in terms of a self-referent, upward CFT style that is normative following trauma for all survivors, regardless of levels of trauma-related distress, and that is applied to any negative events that are encountered.

Introduction. Cannabis use is strongly associated with the use and abuse/dependence of other illicit drugs. Gateway and common liabilities models have been employed to explain this relationship. We sought to examine this association using a combination of the discordant twin design and modeling methods.

Method. We assess the relationship between early cannabis use and the subsequent use and abuse/dependence of other illicit drugs in a population-based sample of male and female twin pairs using four analyses: (i) analysis of the association between early cannabis use and other illicit drug use and abuse/dependence in the entire sample of twins, (ii) assessment of the influence of early cannabis use in twin 1 on twin 2's use or abuse/dependence of other illicit drugs, (iii) use of twin pairs discordant for early cannabis use in a discordant twin design and (iv) a model-fitting procedure.

Results. We found: (i) a strong association between early cannabis use and use and abuse/dependence of other illicit drugs in the sample, (ii) twin 1's early cannabis use is significantly associated with the twin 2's other illicit drug use, (iii) the role of correlated genetic factors with some evidence for a causal influence, and (iv) the correlated liabilities model fits the data well.

Conclusions. Early cannabis use is strongly associated with other illicit drug use and abuse/dependence. The relationship arises largely due to correlated genetic and environmental influences with persisting evidence for some causal influences.

Background. Results of previous research examining long-term residual effects of marijuana use on cognition are conflicting. A major methodological limitation of prior studies is the inability to determine whether differences between users and non-users are due to differences in genetic vulnerability preceding drug use or due to the effects of the drug.

Method. Fifty-four monozygotic male twin pairs, discordant for regular marijuana use in which neither twin used any other illicit drug regularly, were recruited from the Vietnam Era Twin Registry. A minimum of 1 year had passed since the marijuana-using twins had last used the drug, and a mean of almost 20 years had passed since the last time marijuana had been used regularly. Twins were administered a comprehensive neuropsychological test battery to assess general intelligence, executive functioning, attention, memory and motor skills. Differences in performance between marijuana-using twins and their non-using co-twins were compared using a multivariate analysis of specific cognitive domains and univariate analyses of individual test scores. Dose–response relationships were explored within the marijuana-using group.

Results. Marijuana-using twins significantly differed from their non-using co-twins on the general intelligence domain; however, within that domain only the performance of the block design subtest of the Wechsler Adult Intelligence Scale – Revised reached a level of statistical significance.

Conclusions. Out of the numerous measures that were administered, only one significant difference was noted between marijuana-using twins and their non-using co-twins on cognitive functioning. The results indicate an absence of marked long-term residual effects of marijuana use on cognitive abilities.

Background. Numerous twin studies have reported significant genetic contributions to the variability of tobacco initiation (TI), while fewer studies have shown similar results for the persistence of smoking behavior, or nicotine dependence (ND). As the development of ND requires regular tobacco use (RTU) which in turn requires TI, a conditional approach is necessary.

Method. We used structural equation modeling of multi-step conditional processes to examine the relationship between genetic and environmental risk factors for TI, RTU and ND. The tobacco variables were assessed by personal interview in female, male and opposite-sex twin pairs from the population-based Virginia Twin Registry.

Results. The results suggested that the liabilities to TI, RTU and ND were correlated. Over 80% of the variance in liability to TI and RTU were shared, and a smaller proportion was shared between RTU and ND. The heritabilities were estimated at 75%, 80% and 60% respectively for TI, RTU and ND. The variance specific to liability to RTU was entirely accounted for by additive genetic factors. Only a modest part of the heritability in liability of ND was due to genetic factors specific to ND. Shared environmental factors were not significant. No sex differences were found for the sources of variation or causal paths, but prevalences were significantly greater in males versus females.

Conclusions. This study showed significant overlap in the contribution of genetic factors to individual differences in TI, RTU and ND. Furthermore, there was evidence for significant additional genetic factors specific to RTU and ND.

Background. An adoption study of alcoholism suggests that in women, the impact of genetic risk factors become greater in the presence of conflict in the family of origin. Is the same true for cigarette smoking (CS)?

Method. We obtained, in a sample of 1676 twins from female–female twin pairs from a population-based register, a measure of maximum lifetime CS (divided into six ordinal categories) and family dysfunction (FD) assessed as the mean report of up to four informants (twin, co-twin, mother, father). Statistical analysis was conducted by traditional regression analysis and a moderator structural equation twin model using the computer program Mx.

Results. With increasing levels of FD, maximum CS increased substantially while correlations for CS in monozygotic (MZ) and dizygotic (DZ) twins decreased modestly. Regression analyses demonstrated reduced twin-pair resemblance for CS with increasing levels of FD. The best-fit structural equation model found high levels of heritability for CS and no evidence for a role of shared environment. With increasing levels of FD, the proportion of variance in CS due to genetic factors (i.e. heritability) decreased while that due to unique environmental effects increased.

Conclusions. Several different statistical methods suggested that, contrary to prediction, heritability of CS decreased rather than increased with higher levels of dysfunction in the family of origin. The hypothesis that genetic effects for psychiatric and drug-use disorders become stronger in more adverse environments is not universally true.

Background. Clinical and epidemiological studies have reported an association between lifetime cigarette-smoking and panic attacks. Several explanations for this relationship have been proposed, mostly focusing on direct causal pathways. The objective of this study was to investigate a hypothesis of shared vulnerability by examining whether panic attacks and cigarette-smoking share genetic or environmental liability factors.

Method. Questionnaire data on 3172 female–female twins (1409 complete pairs), aged 18–31 years, from a population-based Norwegian twin registry, were used to calculate the correlation between genetic factors and the correlation between environmental factors that influence lifetime measures of panic attacks and daily smoking.

Results. The best-fitting biometrical twin model suggested that genetic factors influencing panic and smoking were uncorrelated. Shared or familial environmental factors were perfectly correlated, and accounted for 75% of the association between the phenotypes. The correlation between individual environmental factors influencing the phenotypes was 0·25 (0·07–0·44). In the full model, the genetic correlation was 0·17 (0·00–1·00), and genetic and shared environmental factors respectively accounted for 18% and 61% of the co-variance between panic and smoking.

Conclusion. The results suggest that panic attacks and lifetime smoking have few or no genetic liability factors in common. The shared environmental factors that influence the two phenotypes are identical. Liability to panic attacks in females appears to be more influenced by shared environmental factors than previously indicated by univariate studies.

Background. The problem-gambling literature has identified a range of individual, cognitive, behavioral and emotional factors as playing important roles in the development, maintenance and treatment of problem gambling. However, familial factors have often been neglected. The current study aims to investigate the possible influence of parental factors on offspring gambling behavior.

Method. A total of 189 families (546 individuals) completed several questionnaires including the South Oaks Gambling Screen (SOGS) and the Gambling Related Cognition Scale (GRCS). The relationships were examined using Pearson product-moment correlations and structural equation modeling (SEM) analyses.

Results. Results showed that generally parents' (especially fathers') gambling cognitions and gambling behaviors positively correlated with offspring gambling behaviors and cognitions. However, SEM analyses showed that although parental gambling behavior was directly related to offspring gambling behavior, parental cognitions were not related to offspring gambling behavior directly but indirectly via offspring cognitions.

Conclusion. The findings show that the influence of parental gambling cognition on offspring gambling behavior is indirect and via offspring cognitions. The results suggest a possible cognitive mechanism of transmission of gambling behavior in the family from one generation to the next.

Background. Elaboration of the concept of cytokine-induced sickness behaviour in recent years has opened new avenues for understanding brain involvement in sickness and recovery processes. Additionally, this has led to much speculation about the role of the immune system in neuropsychiatric syndromes, including depression and chronic fatigue. However, few studies have examined this phenomenon as it naturally occurs in sick humans, and none has attempted to document the quantitative relationships between cytokine levels and non-specific symptoms. The aim of this research was to examine human sickness behaviour and its immunological correlates in documented Epstein–Barr virus (EBV), Q fever or Ross River virus (RRV) infections.

Method. We studied two separate samples. The first consisted of 21 patients with acute Q fever. The second included 48 patients with acute RRV or EBV infection. Psychological and somatic symptom profiles were derived from self-report measures completed at enrolment. Quantification of pro-inflammatory cytokines [interleukin (IL)-1β and IL-6] in sera and supernatants of peripheral blood mononuclear cell (PBMC) cultures was undertaken by specific ELISAs.

Results. Levels of IL-1β and IL-6 spontaneously released from PBMC cultures were consistently correlated with reported manifestations of acute sickness behaviour including fever, malaise, pain, fatigue, mood and poor concentration.

Conclusions. IL-1β and IL-6 produced as part of the host response represent sensitive markers of sickness behaviour in humans with acute infection. Further work is needed to systematically characterize the spectrum and natural history of sickness behaviour in humans and to elucidate its biological basis.

Background. Anxious depression, defined as Major Depressive Disorder (MDD) with high levels of anxiety symptoms, may represent a relatively common depressive subtype, with distinctive features.

Objective. The objective of this study was to determine the prevalence of anxious depression and to define its clinical correlates and symptom patterns.

Method. Baseline clinical and sociodemographic data were collected on 1450 subjects participating in the STAR*D study. A baseline Hamilton Rating Scale for Depression (HAM-D) Anxiety/Somatization factor score of [ges ]7 was considered indicative of anxious depression. The types and degree of concurrent psychiatric symptoms were measured using the Psychiatric Diagnostic Screening Questionnaire (PDSQ), by recording the number of items endorsed by study participants for each diagnostic category. MDD symptoms were assessed by clinical telephone interview with the 30-item Inventory of Depressive Symptomatology (IDS-C30).

Results. The prevalence of anxious depression in this population was 46%. Patients with anxious MDD were significantly more likely to be older, unemployed, less educated, more severely depressed, and to have suicidal ideation before and after adjustment for severity of depression. As far as concurrent psychiatric symptoms are concerned, patients with anxious depression were significantly more likely to endorse symptoms related to generalized anxiety, obsessive compulsive, panic, post-traumatic stress, agoraphobia, hypochondriasis, and somatoform disorders before and after adjustment for severity of depression. Anxious-depression individuals were also significantly less likely to endorse IDS-C30 items concerning atypical features, and were significantly more likely to endorse items concerning melancholic/endogenous depression features.

Conclusion. This study supports specific clinical and sociodemographic correlates of MDD associated with high levels of anxiety (anxious depression).

Background. Ruminating when depressed is thought to lower mood and impair problem-solving, while distraction is thought to alleviate mood and assist problem-solving. The present study investigates each of these proposals using both naturally occurring and experimentally induced rumination and distraction in a sample of patients with major depression.

Method. Thirty-six patients with major depression and 36 control participants were randomly allocated to either a rumination or distraction induction condition. Levels of trait rumination and distraction were measured at baseline, mood and problem-solving were measured before and after the inductions.

Results. In terms of trait measures, depressed patients with higher levels of trait rumination reported poorer mood and gave less effective problem solutions than those who were less ruminative. Trait distraction was not associated with mood or problem-solving. In terms of induced responses, depressed patients who were made to ruminate experienced a deterioration in their mood and gave poorer problem solutions. For those receiving the distraction induction, mood improved in all patients and problem-solving improved in patients who were not naturally ruminating at a high level. Neither induction had an impact on mood or problem-solving in control participants.

Conclusions. Treatment for depression associated with adverse life events may need to target rumination as well as problem-solving deficits if interventions are to be effective. The differential effects of self-applied versus experimentally induced distraction require further investigation. Future research will need to consider that high levels of trait rumination may interfere with the impact of experimental inductions.

Background. Little is known about the extent to which negative life events predict depressive symptoms in ethnically diverse groups or whether this relationship is proximal or enduring.

Method. The relationship between negative life events in adolescence and depressive symptoms in young adulthood was studied in a sample of over 1300 black and white female adolescents. Five domains of life events were assessed at age 16 years and depressive symptoms were measured at age 18 and again at age 21 years. Questions of interest included whether the association continued over time and whether there were specific domains of life events that predicted symptoms better than others.

Results. The total number of negative life events at time 1 predicted depressive symptoms at both time 2 and time 3. Interpersonal loss events and other adversities, however, predicted depressive symptoms only at time 2, whereas at time 3, only interpersonal trauma was a significant predictor. No ethnic differences were found, indicating that the relationship between life events and depressive symptoms appears to be similar for black and white adolescent girls.

Conclusions. The results suggest that negative life events and some specific type of stressors increase the likelihood of the onset of depression symptoms in future years, for both black and white girls. Early preventive efforts should be directed at adolescents who experience loss due to death of a significant other, traumatic events, and psychosocial adversities to forestall the development of depressive symptoms.

Background. Sociological studies have shown that poor social integration confers suicide risk. It is not known whether poor integration amplifies risk after adjusting statistically for the effects of mental disorders and employment status.

Method. A case-control design was used to compare 86 suicides and 86 living controls 50 years of age and older, matched on age, gender, race, and county of residence. Structured interviews were conducted with proxy respondents for suicides and controls. Social integration was defined in reference to two broad levels of analysis: family (e.g. sibship status, childrearing status) and social/community (e.g. social interaction, religious participation, community involvement).

Results. Bivariate analyses showed that suicides were less likely to be married, have children, or live with family. They were less likely to engage in religious practice or community activities and they had lower levels of social interaction. A trimmed logistic regression model showed that marital status, social interaction and religious involvement were all associated with suicide even after statistical adjusting for the effects of affective disorder and employment status. Adding substance abuse to the model eliminated the effects of religious involvement.

Conclusions. The association between family and social/community indicators of poor social integration and suicide is robust and largely independent of the presence of mental disorders. Findings could be used to enhance screening instruments and identify problem behaviors, such as low levels of social interaction, which could be targeted for intervention.