Pituitary volume reduction in schizophrenia following cognitive behavioural therapy.

Cognitive behavioural therapy (CBT) for psychosis (CBTp) aims to lower the stress of psychotic symptoms. Given that the pituitary is involved in stress regulation, CBT-led stress reduction may be accompanied by a change in pituitary volume. This study aimed to determine whether CBTp reduces pituitary volume in schizophrenia. The relation between pre-therapy memory and CBTp-led pituitary volume change was also examined given that poor memory relates to a blunted cortisol awakening response, denoting impaired stress response, in schizophrenia. Pituitary volume was measured at baseline in 40 schizophrenia or schizoaffective disorder patients and 30 healthy participants before therapy. Pituitary volume was measured again 6-9months after patients had either received CBTp in addition to standard care (CBTp+SC, n=24), or continued with standard care alone (SC, n=16). CBTp+SC and SC groups were compared on pituitary volume change from baseline to follow-up. Pre-therapy memory performance (Hopkins Verbal Learning and Wechsler Memory Scale - Logical memory) was correlated with baseline-to-follow-up pituitary volume change. Pituitary volume reduced over time in CBTp+SC patients. Additionally, pre-therapy verbal learning correlated more strongly with longitudinal pituitary volume reduction in the CBTp+SC group than the SC group. To conclude, CBTp reduces pituitary volume in schizophrenia most likely by enhancing stress regulation and lowering the distress due to psychotic symptoms.

Longitudinal Stability of Genetic and Environmental Influences on the Association between Diurnal Preference and Sleep Quality in Young Adult Twins and Siblings.

Overlapping genetic influences have been implicated in diurnal preference and subjective sleep quality. Our overall aim was to examine overlapping concurrent and longitudinal genetic and environmental effects on diurnal preference and sleep quality over ~5 years. Behavioral genetic analyses were performed on data from the longitudinal British G1219 study of young adult twins and nontwin siblings. A total of 1556 twins and siblings provided data on diurnal preference (Morningness-Eveningness Questionnaire) and sleep quality (Pittsburgh Sleep Quality Index) at time 1 (mean age = 20.30 years, SD = 1.76; 62% female), and 862 participated at time 2 (mean age = 25.30 years, SD = 1.81; 66% female). Preference for eveningness was associated with poorer sleep quality at both time points (r = 0.25 [95% confidence intervals {CIs} = 0.20-0.30] and r = 0.21 [CI = 0.15-0.28]). There was substantial overlap in the genetic influences on diurnal preference and sleep quality individually, across time (genetic correlations [rAs]: 0.64 [95% CI = 0.59-0.67] and 0.48 [95% CI = 0.42-.053]). There were moderate genetic correlations between diurnal preference and sleep quality concurrently and longitudinally (rAs = 0.29-0.60). Nonshared environmental overlap was substantially smaller for all cross-phenotype associations (nonshared environmental correlations (rEs) = -0.02 to 0.08). All concurrent and longitudinal associations within and between phenotypes were largely accounted for by genetic factors (explaining between 60% and 100% of the associations). All shared environmental effects were nonsignificant. Nonshared environmental influences played a smaller role on the associations between phenotypes (explaining between -0.06% and 40% of the associations). These results suggest that to some extent, similar genes contribute to the stability of diurnal preference and sleep quality throughout young adulthood but also that different genes play a part over this relatively short time frame. While there was evidence of genetic overlap between phenotypes concurrently and longitudinally, the possible emergence of new genetic factors (or decline of previously associated factors) suggests that molecular genetic studies focusing on young adults should consider more tightly specified age groups, given that genetic effects may be time specific.