Symptom dimensional approach and BDNF in unmedicated obsessive-compulsive patients: an exploratory study

IntroductionThe dimensional approach of the obsessive-compulsive symptoms may help to find more homogeneous groups of patients. The brain derived neurotrophic factor (BDNF) may help to identify neurobiological differences between obsessive-compulsive symptom dimensions.

We compared serum BDNF (pg/μg) levels of 25 unmedicated patients meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for obsessivecompulsive disorder (OCD) and 25 controls, using the Dimensional Yale-Brown Obsessive-Compulsive Scale, the Yale-Brown Obsessive-Compulsive Scale and the Beck's Anxiety and Depression Inventories.

There were no sociodemographic differences between the groups. The standard error of mean serum BDNF levels were reduced in unmedicated OCD patients (0.47+0.038) when compared to healthy controls (0.75+0.060) (P<.001). The patients with the presence of sex/religion obsessive-compulsive symptoms (OCS) dimension (P=.002), with chronic course of OCS (P=.022) and the presence of lifetime major depression (P=.016) and social anxiety (P=.030) presented higher levels of BDNF than OCD patients without those features. The severity of aggression (P=.039) and sex/religion (P<.001) OCS dimension presented direct (moderate and strong, respectively) correlation with serum BDNF levels in this sample. Serum BDNF levels were decreased in OCD patients when compared to healthy controls.Discussion/ConclusionSexual and religious content of symptoms and aggression and sex/religion dimensions severity should be better explored, since these specific OCS dimensions could be based on neurocircuits diverse from those of the other OCS dimensions.