Predictive value of cardiometabolic biomarkers and depressive symptoms for symptom severity and quality of life in patients with psychotic disorders.

BACKGROUND: Patients with psychotic disorders show higher rates of the metabolic syndrome (MS) between the cluster of severe mental illnesses. Depressive symptoms can worsen outcomes of individuals with psychotic disorders. However, research on the association between MS and depression in psychotic disorders and their relevance to outcomes is lacking. METHODS: We investigated the association between depression and cardiometabolic biomarkers in psychotic disorders and the predictive value of depressive symptoms on psychopathological severity and quality of life (QoL). 406 patients with psychotic disorders were recruited as part of the Improving Physical Health and Reducing Substance Use in Severe Mental Illness randomised controlled trial. Depression, psychotic symptoms, QoL, waist circumference, triglycerides, high-density lipoprotein cholesterol (HDL-C), blood pressure, and fasting glucose of patients were assessed at baseline and 12 months. Sensitivity analyses were conducted to test the effect of treatment. RESULTS: More severe baseline symptoms of depression significantly predicted worse 12-month psychotic symptoms and lower mental health related QoL at 12 months. These associations held after controlling for alcohol use, gender, ethnicity, education, and mental health related QoL Baseline. Depressive symptoms also correlated with waist circumference at both baseline and 12 months, after controlling for multiple testing. CONCLUSION: Individuals with psychotic disorders experiencing more severe depressive symptoms are more likely to have larger waist circumference contemporaneously and 12 months later, as well as more severe psychotic symptoms and worse QoL at follow-up. This highlights the need for evaluation of strategies to address depression in the management of psychotic disorders.

Is deterioration of IQ a feature of first episode psychosis and how can we measure it?

Estimates of pre-morbid IQ are widely used to measure the trajectory of cognitive function and decline in people with schizophrenia. This study examined the usefulness of two indices of decline to identify cognitive subtypes in first episode psychosis, and to determine the specificity of non-IQ neuropsychological impairments in this population. Neuropsychological data were collected from 118 first episode psychosis patients and compared to 118 epidemiologically matched controls. The National Adult Reading Test (NART) and the Information subtest of the WAIS-III were compared as indicators of crystallised intelligence or 'pre-morbid IQ'. Measurement of NART minus current full scale IQ (FSIQ) (where 10 points discrepancy is the decline criterion) did not reveal a large group of individuals with 'deteriorating' IQ patterns. Using the Information subtest and the same decline criteria, a 'deteriorating' patient group emerged (36%) but was matched by a larger 'deteriorating' control group (45%). The 'deteriorating' patient group performed at a low IQ level for tasks that loaded highly on performance ability but a relatively high level for tasks measuring verbal skills. Verbal memory discriminated patients from controls better than IQ. Compared to controls, patients showed large selective impairments of verbal episodic memory (effect size, d=1.4) These data suggest that in first episode populations, caution should be exercised in inferring deterioration of IQ from discrepancies between reading-based and other IQ tests. Rather, sub-groups of patients and controls do show greater verbal aptitude in comparison to performance skills. Memory is generally impaired in first episode patients regardless of IQ.