Objectives: Previous studies suggest that childhood trauma, stressful life events, and cannabis use are associated with psychosis. We aimed to explore whether these environmental factors have an effect on hypothalamic-pituitary-adrenal (HPA) axis indices in recent-onset psychosis.Methods: We studied 56 recent-onset psychosis outpatients and 47 healthy controls. Childhood trauma was assessed with the Childhood Trauma Questionnaire. Stressful life events were assessed with the Holmes-Rahe Social Readjustment Scale. Cannabis use was assessed by semistructured interviews. Several HPA axis measures were analysed in saliva: cortisol awakening response (CAR), diurnal cortisol slope, and dexamethasone suppression test ratio (DSTR) after 0.25 mg of dexamethasone. Multiple linear regression analyses were conducted to explore the contribution of environmental factors to each HPA axis measure while adjusting for covariates (diagnosis, age, gender, smoking, body mass index and treatments).Results: There were no significant differences in HPA axis measures between diagnostic groups. Cannabis use was associated with a more flattened diurnal cortisol slope (standardized β = 0.21, p = 0.038), independent of recent-onset psychosis diagnosis. No associations were found between environmental factors and other HPA axis measures (CAR, DSTR).Conclusions: Our study provides evidence for the effect of cannabis exposure in cortisol secretion patterns in both healthy controls and recent-onset psychosis patients.
Keywords: Stress; cannabis; childhood trauma; cortisol; psychosis.