Possibilities of using laboratory biomarkers for the objective diagnosis of depressive disorders

Abstract

Objective: to assess the possibility of using laboratory biomarkers to objectify psychopathological disorders in patients with depressive spectrum disorders (RSDs). Patients and methods. The investigation enrolled 63 patients (mean age, 31.7±8.9 years) with new-onset RSDs of different etiologies. Group 1 included 21 patients with a mild to moderate depressive episode (DE); Group 2 consisted of 42 patients with neurotic depressive disorders (adjustment disorders). The severity of anxiety and depression was assessed using the Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Hospital Anxiety and Depression Scale. In addition, the investigators studied laboratory\xa0 parameters: the levels of cortisol, homocysteine, prolactin,\xa0 vitamin B 12 , cortisol, interleukin (IL)-1 β , IL-6, and tumor necrosis\xa0 factor- α (TNF- α ) in serum and platelet serotonin. They\xa0 also estimated changes in the most significant laboratory\xa0 parameters in 31 patients with depressive disorders: in 15 with\xa0 DE and in 16 with neurotic depression who had received 4-week monotherapy with agomelatine 25 mg/day. Results and discussion. The differential diagnosis of\xa0 psychopathological disorders based on the clinical and\xa0 psychopathological method and psychometric assessment of\xa0 the patient s condition was shown to be difficult. It was\xa0 established that the objectification of these disorders using\xa0 known laboratory biomarkers (cortisol and platelet serotonin) did not give an unambiguous answer. At the same time, the\xa0 assessment of immunological parameters (the levels of\xa0 proinflammatory cytokines, such as IL-6, TNF- α ) can help to\xa0 solve this problem. The investigation also demonstrated that the use of non-monoaminergic antidepressants (MT 1 /MT 2 -type\xa0 melatonin receptor agonists) contributed to the reduced level of proinflammatory cytokines, which opens up\xa0 opportunities for finding new therapeutic approaches to\xa0 treating RSDs.\xa0 Conclusion. Usage of biological markers may contribute not only to improvement in the accuracy of mental disorders\xa0 diagnosis but also to the development of new treatment approaches. Simultaneously, the selective use of individual biological markers (biochemical, metabolic, immunological, etc.)\xa0 is not very informative; therefore, their comprehensive\xa0 assessment is required.