Reduced Venous Blood Basophil Count and Anxious Depression in Patients with Major Depressive Disorder

Objective Anxious depression has a distinct neurobiology, clinical course and treatment response from non-anxious depression. Role of inflammation in anxious depression has not been examined. As an exploratory study to characterize the role of inflammation on a development of anxious depression, we aimed to determine the relationship between white blood cell (WBC) subset counts and anxiety in individuals with major depressive disorder (MDD). Methods A total of 709 patients who were newly diagnosed with MDD were recruited. Anxiety levels of participants were evaluated using the Anxiety/Somatization subitem of the Hamilton Depression Rating Scale. The association between WBC subset fraction and anxiety was evaluated. Results Basophil and eosinophil sub-fractions showed significant negative correlations with HAM-D anxiety/somatization factor scores (basophils: r=-0.092, p=0.014 and eosinophils: r=-0.075, p=0.046). When an anxiety score (a sum of somatic and psychic anxiety) was entered as a dependent variable, only basophils showed significant negative association with the anxiety scores after adjusting for all other WBC subset counts and demographic factors (t=-2.57, p=0.010). Conclusion This study showed that anxious depression had a decreased basophil subfraction, which might be associated with involvement of inflammation in development of anxious depression.