Schizophrenia is a heterogeneous disorder with substantial heritability. The use of endophenotypes may help clarify its aetiology. Measures from the smooth pursuit and antisaccade eye movement tasks have been identified as endophenotypes for schizophrenia in twin and family studies. However, the genetic basis of the overlap between schizophrenia and these oculomotor markers is largely unknown. Here, we tested whether schizophrenia polygenic risk scores (PRS) were associated with oculomotor performance in the general population.

Analyses were based on the data of 2956 participants (aged 30–95) of the Rhineland Study, a community-based cohort study in Bonn, Germany. Genotyping was performed on Omni-2.5 exome arrays. Using summary statistics from a recent meta-analysis based on the two largest schizophrenia genome-wide association studies to date, we quantified genetic risk for schizophrenia by creating PRS at different p value thresholds for genetic markers. We examined associations between PRS and oculomotor performance using multivariable regression models.

Higher PRS were associated with higher antisaccade error rate and latency, and lower antisaccade amplitude gain. PRS showed inconsistent patterns of association with smooth pursuit velocity gain and were not associated with saccade rate during smooth pursuit or performance on a prosaccade control task.

There is an overlap between genetic determinants of schizophrenia and oculomotor endophenotypes. Our findings suggest that the mechanisms that underlie schizophrenia also affect oculomotor function in the general population.

Studies have shown higher rate of various psychiatric disorders among individuals with substance abuse / dependence. There is little data in developing countries, such as Pakistan, on prevalence of psychiatric co-morbidity in this population and impact on treatment.

To assess the psychiatric co-morbidity among individuals with substance dependence and to determine its demographic associations in patients with substance dependence in Pakistan.

This was a descriptive study conducted at a tertiary care hospital in Pakistan. Participants were 588 individuals with substance dependence admitted to a tertiary care hospital in Pakistan, mainly in male inpatient substance dependence unit. The patients were assessed for psychiatric co-morbidity using DSM IV criteria. Informed consent was obtained. The study was approved by the Institutional Research Committee. The results were obtained by using chi square test on SPSS 17.

Out of 588, 200 patients (34%) were found co-morbid with other psychiatric disorders along with substance dependence. Reason of first substance use and history of previous substance dependence were observed to be significantly associated with co-morbid psychiatric disorders, x2 (48, n = 549) = 112.396, p < 0.01 and x2 (18, n = 588) = 29.66, p = 0.041 respectively.

1. 1. There was high rate of psychiatric co-morbidity among individuals with substance dependence in this sample.

2. 2. Depression, personality disorders and anxiety disorders were the major co-morbid diagnosis among this population.