Change in IQ in schizophrenia patients and their siblings: a controlled longitudinal study.

BACKGROUND: Lower intelligence quotient (IQ) has frequently been reported in patients with schizophrenia. However, it is unclear whether IQ declines (further) after illness onset and what the familial contribution is to this change. Therefore, we investigate IQ changes during the course of illness in patients with non-affective psychosis, their siblings and controls. METHODS: Data are part of the longitudinal Genetic Risk and Outcome of Psychosis (GROUP) study in the Netherlands and Belgium. Participants underwent three measurements, each approximately 3 years apart. A total of 1022 patients with non-affective psychosis [illness duration: 4.34 (s.d. = 4.50) years], 977 of their siblings, and 565 controls had at least one measure of IQ (estimated from four subtests of the WAIS-III). RESULTS: At baseline, IQ was significantly lower in patients (IQ = 97.8) and siblings (IQ = 108.2; p < 0.0001) than in controls (IQ = 113.0; p < 0.0001), and in patients as compared with siblings (p < 0.0001). Over time, IQ increased in all groups. In siblings, improvement in IQ was significantly more pronounced (+0.7 points/year) than in patients (+0.5 points/year; p < 0.0001) and controls (+0.3 points/year; p < 0.0001). IQ increase was not significantly correlated with improvement in (sub)clinical outcome in any of the groups. CONCLUSIONS: During the first 10 years of the illness, IQ increases to a similar (and subtle) extent in a relatively high-functioning group of schizophrenia patients and controls, despite the lower IQ in patients at baseline. In addition, the siblings' IQ was intermediate at baseline, but over time the increase in IQ was more pronounced.

Childhood abuse and neglect in relation to the presence and persistence of psychotic and depressive symptomatology.

BACKGROUND: The association between childhood trauma and psychotic and depressive symptomatology is well established. However, less is known about the specificity and course of these symptoms in relation to childhood trauma. METHOD: In a large sample (n = 2765) of patients with psychosis (n = 1119), their siblings (n = 1057) and controls (n = 589), multivariate (mixed-effects) regression analyses with multiple outcomes were performed to examine the association between childhood trauma and psychotic and depressive symptomatology over a 3-year period. RESULTS: A dose-response relationship was found between childhood trauma and psychosis. Abuse was more strongly associated with positive symptoms than with negative symptoms whereas the strength of the associations between neglect and positive and negative symptoms was comparable. In patients, similar associations between childhood trauma and psychotic or depressive symptoms were found, and in siblings and controls, stronger associations were found between trauma and depressive symptomatology. Childhood trauma was not related to a differential course of symptoms over a 3-year time period. CONCLUSIONS: In congruence with earlier work, our findings suggest that childhood trauma, and abuse in particular, is associated with (subthreshold) psychosis. However, childhood trauma does not seem to be associated with a differential course of symptoms, nor does it uniquely heighten the chance of developing (subthreshold) psychotic symptomatology. Our results indicate that trauma may instead contribute to a shared vulnerability for psychotic and depressive symptoms.

Childhood maltreatment, adult attachment and psychotic symptomatology: a study in patients, siblings and controls.

PURPOSE: The association between childhood maltreatment (ChM) and psychotic disorders is well established. However, there is an ongoing debate about which factors account for this relationship. One explanation is that the relationship between ChM and psychosis is mediated by adult attachment style. Therefore, in this study, we aimed to investigate whether adult attachment style mediates the relationship between ChM and positive and negative symptomatology. METHODS: We investigated the relation between ChM and psychotic symptoms, taking into account levels of (insecure) attachment, in 131 patients with psychotic illness, 123 siblings and 72 controls. ChM was assessed with the Childhood Trauma Questionnaire (CTQ). Attachment dimensions of anxiety and avoidance were measured using the Psychosis Attachment Measure (PAM). RESULTS: In both patients and siblings, ChM predicted positive symptoms and this relationship was partly mediated by attachment style. This relationship was found to be stronger for siblings than for patients. ChM predicted negative symptoms in patients and siblings. In the patient sample, attachment style did not mediate the relationship between ChM and negative symptoms, whereas attachment style was found to be a mediator in the sibling sample. CONCLUSIONS: ChM was associated with positive and negative symptomatology in both patients and siblings. Particularly in siblings, the relationship between ChM and psychosis seems to be mediated by adult attachment style. Perhaps attachment style may play a more prominent role on a subclinical level.

Childhood bullying and the association with psychosis in non-clinical and clinical samples: a review and meta-analysis.

BACKGROUND: Approximately 11% of schoolchildren are bullied on a regular basis. It has been argued that continuous exposure to stress is related to the development of psychotic symptoms. The current study sought to investigate whether being bullied in childhood is related to the development of psychotic symptoms. METHOD: A search of PubMed, PsycINFO and EMBASE was conducted. The reference lists of included papers were searched to identify other eligible papers. A meta-analysis was performed on a subgroup of studies. RESULTS: We found four clinical and 10 general population studies that met inclusion criteria. The results of the clinical studies were mixed. However, the results of the non-clinical studies provided more consistent evidence that school bullying is related to the development of non-clinical psychotic symptoms. Stronger associations were found with increased frequency and severity and longer duration of being bullied. We performed a meta-analysis on seven population-based studies, yielding unadjusted and adjusted odds ratios (ORs) of 2.7 [95% confidence interval (CI) 2.1-3.6] and 2.3 (95% CI 1.5-3.4) respectively. CONCLUSIONS: Although there is some evidence of an association between bullying and psychosis in clinical samples, the research is too sparse to draw any firm conclusions. However, population-based non-clinical studies support the role of bullying in the development of psychotic symptoms later in life. These findings are consistent with findings of an increased risk of psychotic symptoms among those exposed to other types of abuse.