Investigating the Role of Obesity, Circadian Disturbances, and Lifestyle Factors in People with Schizophrenia and Bipolar Disorder: Study Protocol for the SOMBER Trial

The SOMBER trial aims to explore the relationship between circadian rhythms, obesity, and mental disorders in 80 adults divided into four groups: those with obesity and schizophrenia, obesity and bipolar disorder, obesity without mental or sleep disorders, and a control group without obesity, mental, or sleep disorders. Over two days, participants provide hair follicle and saliva samples while data on diet, body temperature, light exposure, sleep, and physical activity are collected. Hair follicles are analyzed for circadian gene expression, and saliva for cortisol and melatonin levels. The study uses cosinor analysis to investigate circadian rhythms, with a participant-tailored sampling schedule to reduce daily routine disruptions. The goal is to understand factors contributing to circadian disruptions in these populations, potentially guiding future management strategies.