Positive, negative and disorganised psychotic symptom dimensions are associated with clinical and developmental variables, but differing definitions complicate interpretation. Additionally, some variables have had little investigation.

To investigate associations of psychotic symptom dimensions with clinical and developmental variables, and familial aggregation of symptom dimensions, in multiple samples employing the same definitions.

We investigated associations between lifetime symptom dimensions and clinical and developmental variables in two twin and two general psychosis samples. Dimension symptom scores and most other variables were from the Operational Criteria Checklist. We used logistic regression in generalised linear mixed models for combined sample analysis (n = 875 probands). We also investigated correlations of dimensions within monozygotic (MZ) twin pairs concordant for psychosis (n = 96 pairs).

Higher symptom scores on all three dimensions were associated with poor premorbid social adjustment, never marrying/cohabiting and earlier age at onset, and with a chronic course, most strongly for the negative dimension. The positive dimension was also associated with Black and minority ethnicity and lifetime cannabis use; the negative dimension with male gender; and the disorganised dimension with gradual onset, lower premorbid IQ and substantial within twin-pair correlation. In secondary analysis, disorganised symptoms in MZ twin probands were associated with lower premorbid IQ in their co-twins.

These results confirm associations that dimensions share in common and strengthen the evidence for distinct associations of co-occurring positive symptoms with ethnic minority status, negative symptoms with male gender and disorganised symptoms with substantial familial influences, which may overlap with influences on premorbid IQ.

Cigarette smoking is more prevalent among individuals with psychiatric disorders than the general population. Obsessive-compulsive disorder (OCD) may be an intriguing exception, although no recent study has investigated this hypothesis in OCD patients. Moreover, it is unknown whether reduced smoking rates are present in unaffected first-degree relatives of OCD patients.

We assessed smoking prevalence in adults with OCD and unaffected parents of youth with OCD (PYOCD). To this end, 113 adults with OCD completed online questionnaires assessing symptom severity and smoking status. Smoking status was obtained from an independent sample of 210 PYOCD assessed for psychiatric diagnoses.

Smoking prevalence rates in adults with OCD (13.3%; n = 15) and PYOCD (9.5%; n = 20) samples were significantly lower than those found in representative samples of the general population (19–24%, all P < .001) and Axis I disorders (36–64%; all P < .001). There were no smokers in the adult OCD subset without clinically significant depressive symptoms (n = 54).

Low prevalence of smoking in OCD may be familial and unique among psychiatric disorders, and might represent a possible state-independent OCD marker. Hypotheses concerning the uncharacteristically low prevalence rates are discussed with relation to OCD phenomenology and pathophysiology.

Cognitive impairment is a familial and heritable aspect of major psychoses and might be a shared vulnerability marker for schizophrenia and BP. However, it is not clear whether some aspects of cognitive deficits are uniquely associated with risk for specific diagnoses.

A novel meta-analysis of cognitive functions in first-degree relatives of probands with bipolar disorder (BP-Rel) and schizophrenia (Sch-Rel) was conducted. Current meta-analysis included 20 studies and compared cognitive functions of 1341 Sch-Rel, 939 BP-Rel and 1427 healthy controls.

Sch-Rel was associated with cognitive deficits in all domains (d = 0.20–0.58) and BP-Rel underperformed healthy controls in processing speed, verbal fluency and speed based executive function tests (d = 0.33–0.41). Sch-Rel underperformed BP-Rel in general intellectual ability, working memory, verbal memory, planning, processing speed and fluency (d = 0.24–0.42).

Inefficiency in processing information and impaired processing speed might be common vulnerability factors for major psychoses. On the other hand, low performance in accuracy based tasks and deficits in general intellectual ability, verbal learning, planning and working memory might be more specifically associated with risk for schizophrenia.

Neuropsychological impairment, including deficits in social cognition is evident in subjects at genetic high-risk for psychosis. However, findings in youth at genetic risk to bipolar disorder (BP) have been suggested to be less supportive of premorbid deficits. We aimed to conduct a meta-analysis of cognitive deficits in youth with familiar risk for bipolar disorder (FHR-BD).

A novel meta-analysis of FHR-BD (mean age 10–25), including 18 studies (786 offsprings/siblings of patients with BD and 794 healthy controls), was conducted.

Both general cognition (d = 0.29, CI = 0.15–0.44) and social cognition (d = 0.23, CI = 0–0.45) were impaired in FHR-BD. In comparison to controls, FHR-BD had significant deficits in several cognitive domains, including visual memory (d = 0.35), verbal memory (d = 0.21), processing speed (d = 0.26) and sustained attention (d = 0.36). There was no significant difference between FHR-BD and controls in planning and working memory.

Cognitive deficits are evident in individuals who are at genetic high-risk for developing BD. Neurodevelopmental abnormalities are likely playing a role not only in schizophrenia but also in BD.

Identifying clinical features that predict conversion to bipolar disorder (BD) in those at high familial risk (HR) would assist in identifying a more focused population for early intervention.

In total 287 participants aged 12–30 (163 HR with a first-degree relative with BD and 124 controls (CONs)) were followed annually for a median of 5 years. We used the baseline presence of DSM-IV depressive, anxiety, behavioural and substance use disorders, as well as a constellation of specific depressive symptoms (as identified by the Probabilistic Approach to Bipolar Depression) to predict the subsequent development of hypo/manic episodes.

At baseline, HR participants were significantly more likely to report ⩾4 Probabilistic features (40.4%) when depressed than CONs (6.7%; p < .05). Nineteen HR subjects later developed either threshold (n = 8; 4.9%) or subthreshold (n = 11; 6.7%) hypo/mania. The presence of ⩾4 Probabilistic features was associated with a seven-fold increase in the risk of ‘conversion’ to threshold BD (hazard ratio = 6.9, p < .05) above and beyond the fourteen-fold increase in risk related to major depressive episodes (MDEs) per se (hazard ratio = 13.9, p < .05). Individual depressive features predicting conversion were psychomotor retardation and ⩾5 MDEs. Behavioural disorders only predicted conversion to subthreshold BD (hazard ratio = 5.23, p < .01), while anxiety and substance disorders did not predict either threshold or subthreshold hypo/mania.

This study suggests that specific depressive characteristics substantially increase the risk of young people at familial risk of BD going on to develop future hypo/manic episodes and may identify a more targeted HR population for the development of early intervention programs.

Trichotillomania (TTM) is a psychiatric syndrome characterised by the inability to control repetitive hair pulling. Psychiatric data reveal that TTM is not usually prevalent among all family members of patients, and so far only one case of familial TTM has been reported.

In this study, we report a case of familial TTM that afflicted four sisters and discuss the importance of genetic factors in this disorder.

This report suggests that, similar to many other psychiatric disorders, TTM can be detected in other family members and that genetic factors not only have a significant role in the development of such disorders but also in determination of the disorder subtype. This report also shows that the comorbidities in one member of the family might predict the existence of comorbidities in other members. On the basis of response to medication.

the authors suggest that a genetic disorder like polymorphism in serotonin receptors or dopamine can cause such a disorder.

Depression is a clinically relevant dimension, associated with both positive and negative symptoms, in patients with schizophrenia. However, in siblings it is unknown whether depression is associated with subclinical positive and negative symptoms.

Depressive symptoms and their association with positive and negative symptoms were examined in 813 healthy siblings of patients with a non-affective psychotic disorder, 822 patients and 527 healthy controls. Depressive episodes meeting DSM-IV-TR criteria (lifetime) and depressed mood (lifetime) were assessed with the Comprehensive Assessment of Symptoms and History (CASH) in all three groups. In the patient group, the severity of positive and negative psychosis symptoms was assessed with the CASH. In the siblings and healthy controls, the severity of subclinical psychosis symptoms was assessed with the Community Assessment of Psychic Experiences (CAPE).

Patients reported more lifetime depressed mood and more depressive episodes than both siblings and controls. Siblings had a higher chance of meeting lifetime depressive episodes than the controls; no significant differences in depressed mood were found between siblings and controls. In all three groups the number and duration of depressive symptoms were associated with (sub)clinical negative symptoms. In the patients and siblings the number of depressive symptoms was furthermore associated with (sub)clinical positive symptoms. Finally, lifetime depressed mood showed familial clustering but this clustering was absent for lifetime depressive episodes.

These findings suggest that a co-occurring genetic vulnerability for both depressive and psychotic symptomatology exists on a clinical and a subclinical level.

Co-morbidity of mood and anxiety disorders is common and often associated with greater illness severity. This study investigates clinical correlates and familiality of four anxiety disorders in a large sample of bipolar disorder (BP) and major depressive disorder (MDD) pedigrees.

The sample comprised 566 BP families with 1416 affected subjects and 675 MDD families with 1726 affected subjects. Clinical characteristics and familiality of panic disorder, social phobia, specific phobia and obsessive-compulsive disorder (OCD) were examined in BP and MDD pedigrees with multivariate modeling using generalized estimating equations.

Co-morbidity between mood and anxiety disorders was associated with several markers of clinical severity, including earlier age of onset, greater number of depressive episodes and higher prevalence of attempted suicide, when compared with mood disorder without co-morbid anxiety. Familial aggregation was found with co-morbid panic and OCD in both BP and MDD pedigrees. Specific phobia showed familial aggregation in both MDD and BP families, although the findings in BP were just short of statistical significance after adjusting for other anxiety co-morbidities. We found no evidence for familiality of social phobia.

Our findings suggest that co-morbidity of MDD and BP with specific anxiety disorders (OCD, panic disorder and specific phobia) is at least partly due to familial factors, which may be of relevance to both phenotypic and genetic studies of co-morbidity.

Offspring of parents with mental disorder are at risk of a range of adverse outcomes. We sought to establish whether such risks extend to offending by examining rates of criminal conviction, including conviction for violent and sexual offences, among offspring of parents with mental disorder compared to offspring without parental disorder.

From a random sample of the Danish population, a cohort aged ⩽15 years (n=412 117) was followed for the occurrence of conviction between January 1981 and December 2006. Incidence rate ratios (IRRs) and cumulative incidences for offspring conviction by parental mental disorder status were calculated using a Cox regression model. Analyses were repeated for conviction for a serious first offence.

Offspring with history of parental mental disorder had higher rates of conviction than those without parental disorder; rates were highest for those with two affected parents [IRR 3.39, 95% confidence interval (CI) 3.08–3.73]. The association persisted when parental gender, offspring gender and the nature of parental disorder were considered. Absolute rates were lower but relative rates higher for female offspring (IRR 3.26 for males with two affected parents, 4.52 for females). Similar patterns were seen for conviction for serious offences. Associations were attenuated after adjustment was made for family socio-economic position (SEP) and parental criminality.

Offspring of parents with mental disorder represent a group at elevated risk of criminality. This raises the possibility of shared familial vulnerability for mental disorder and criminal behaviour, and highlights the need to consider early identification and intervention in this group.

Ménière's disease is not uncommon, with an incidence in Caucasians of about one in 2000. The incidence peaks in the fifth decade. Cases are usually isolated or sporadic, but in perhaps five per cent other family members are affected. We report here the clinical and genetic characteristics of a comprehensive set of familial Ménière's disease cases from the UK.

Forty-six affected families were studied. All cases were diagnosed using the American Academy of Otolaryngology–Head and Neck Surgery committee on hearing and equilibrium 1995, or more stringent, criteria.

Autosomal dominant inheritance with reduced penetrance was the most likely mode of inheritance overall. Apparent genetic anticipation was observed, but may also be a result of ascertainment bias given the collection strategy. There was also a slight tendency for cases to result from maternal transmission within the families in this set. The family pedigrees are presented, and the authors have also set up a website at which all the pedigrees may be viewed in greater detail.