Sleep and psychopatholgy: in the general population and bipolar disorder

This thesis set out to investigate the relation between sleep and psychopathology. We examined two groups; bipolar patients and adolescents from the general population that are both characterized by mood fluctuations and are vulnerable for disturbances in sleep-wake pattern. Using wearables (watches) to obtain actigraphy measurements, we found that bipolar patients had normal sleep patterns outside their episodes, suggesting that bipolar sleep disturbances are mainly state-dependent, rather than a trait of the disorder. A remarkable finding of our studies was that effective sleep was related to lower integrity of white matter tracts in bipolar disorder patients, whereas in the general population this relationship was the reverse (better tracts in those that slept well). A likely explanation for this difference is the use of antipsychotic medication in the patient group. In a large epidemiological sample of over 15,000 youth we found that poor sleep was related to psychosocial problems, suicidality and health risk behavior. The association between sleep and health risk behavior was only partially mediated by emotional problems, suggesting that not only the relation between emotional deregulation and sleep disturbances plays a role in the occurrence of behavioural problems, but that sleep deprivation in itself may lead to risky behaviour.