CHARACTERISTICS OF DEPRESSION IN PATIENTS WITH DIFFERENT CHRONOTYPES

Abstract

Background: Approximately 30−40% of depressive patients does not improve or show a partial response. Since biological rhythm involved in the pathogenesis of mood disorders is regarded as a unique characteristic of a person, it opens new opportunities for personalized medicine.Aim: to evaluate clinical characteristics and treatment effectiveness in depressive patients with different chronotypes.Materials and methods: In prospective, hospital-based study MADRS was performed weekly (dMADRS), therapeutic response (R) was defined as a 50% or greater decrease from baseline in the score. Chronotype was evaluated using the Morningness−Eveningness Questionnaire (MEQ). Participants completed a questionnaire package: HDRS-21, PSQI, ТОВ, «individual minute». Statistical analysis was performed using Excel for Windows, Statistica 13.0.Results: All patients (n=100, mean age 48±16 yrs) were divided into groups based on their circadian type: evening types (ETs) had more severe condition; antidepressants (SSRIs; R=72%) were effective given at morning in ETs, at evening (other; R=100%) ― in morning types (MTs) (p0.00001) with a greater reduction in depressive symptoms (p0.05). Prescribing drugs with balanced potency were effective in both groups (F=4.62, p=0.032). Cluster analysis on 25 clinical, biological, and therapeutic variables to establish the role of chronotype as a factor important for identifying patients with similar socio-demographic, clinical, and health characteristics was conducted. Cluster 1 achieved a reduction of depression severity (19% MTs; R=81%; 43.4±17.7 yrs; single episode; dMADRS 16.9±2.7; 23% monotherapy). Cluster 3 (80% ETs; R=50%; 40.4±15.2; early onset dMADRS 15.23±2.29; 7% monotherapy) was the most unfavorable prognostic group.Conclusions: Depressive patients with morning/evening chronotypes have significant differences in clinical presentation, the course of the illness and efficacy of antidepressants. Evening chronotype was found to be associated with poor prognosis. Circadian typology should be considered when choosing the appropriate therapeutic options.