Background/Aims: There is increasing evidence that neuroinflammation and inflammatory processes play roles in psychiatric disorders. In the present study, the purpose was to investigate the role of systemic inflammation in major depressive disorder (MDD) subtypes, compare the inflammation rates between subtypes with healthy controls, help elucidate the pathophysiology of the disease, and contribute to the determination of biochemical parameters. Methods: A total of 244 participants (180 patients diagnosed with MDD (30 from the subtypes of catatonia, melancholy, mixed, atypical, anxious distress, psychosis), and 64 healthy controls were included in the study. Participants who had a history of comorbid medical disease and/or any medication use were excluded from the study. Hemoglobin, hematocrit, platelets, neutrophils, lymphocytes, monocytes, Monocyte/Lymphocyte Ratio (MLR), Neutrophil/Lymphocyte Ratio (NLR), and Platelet/Lymphocyte Ratio (PLR) of the groups were compared. Results: Sex, age and Body Mass Index (BMI) values did not differ between MDD subtypes and healthy controls (p>0.05). No differences were detected between healthy controls and MDD subtypes in neutrophil and lymphocyte counts (p>0.05). NLR and MLR values differed between healthy controls and MDD subtypes (p=0.023, p=0.002, respectively). NLR and MLR were significantly higher in the MDD subtype with catatonic characteristics than in healthy controls (p=0.002, p
Aslan et al. (Wed,) studied this question.