Sleep disorders are highly prevalent in major depressive disorder (MDD) and influence both the clinical presentation and treatment outcomes (2,7, 11). This review aims to summarise current evidence on the types of sleep disturbances linked to MDD, neurobiological mechanisms connecting sleep to depression, and available treatment strategies. Some form of sleep disturbance affects up to 90% of patients suffering from MDD, with insomnia being the most prevalent one (2, 14). Sleep and depression are connected by neurobiological pathways, including dysregulation of monoaminergic neurotransmission, disruption of circadian rhythms, chronic inflammation and hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) (6, 9, 14, 18). From a clinical perspective, sleep disturbances are associated with worse treatment response and higher relapse rates in MDD. Management strategies include both pharmacological and non-pharmacological interventions, combining antidepressant and hypnotic drugs with cognitive-behavioural therapy and light therapy (6, 9, 16, 17). In conclusion, sleep disturbances play a crucial role in the development and course of major depressive disorder. Early identification and treatment of sleep problems should be considered an integral part of comprehensive depression management.