Alterations in sleep and the biological clock in mood disorders: State of the art and therapeutic approaches.

Sleep disorders such as insomnia, hypersomnolence, nightmares and circadian rhythm disorders play a critical role across all stages of mood disorders, including Chronos syndrome, and are recognized as significant risk factors for their onset, relapse, and recurrence. Moreover, emerging evidence suggests that the co-occurrence of sleep or circadian disruptions with mood disturbances may represent a more severe and distinct clinical phenotype, likely associated with a poorer prognosis than when each condition occurs independently. Personalized interventions targeting sleep, circadian rhythms, and mood symptoms, are increasingly being developed and implemented across the various phases of mood disorders. These include Cognitive Behavioral Therapy for Insomnia (CBT-I) combined with chronotherapeutic approaches for insomnia disorder, chronotherapeutics for circadian rhythm disturbances, Imagery Rehearsal Therapy (IRT) for nightmares disorders, and wake-promoting agents for hypersomnolence. All of these treatments should be integrated with the optimization of mood disorder management, both preventive and curative, including the use of antidepressants, mood stabilizers, and chronotherapeutic strategies.