Independence of Peripheral Brain-Derived Neurotrophic Factor from Depression and Anxiety Symptoms in Cocaine Use Disorder: An Initial Description.

Cocaine use disorder (CUD) presents high comorbidity with mood symptoms that impair recovery processes and facilitate relapses. Peripheral brain-derived neurotrophic factor (BDNF) is negatively correlated with mood symptoms in depressive disorders. However, whether a correlation exists between BDNF and mood in CUD is still unknown. Thus, in this cross-sectional study, we explored the potential relationship between peripheral BDNF levels and depression and anxiety symptoms in CUD. Serum peripheral BDNF was determined by the ELISA method. Standardized Hamilton Depression (HDRS) and Anxiety (HARS) inventories were administered. Twenty-nine seeking-treatment CUD participants under stable medication (female = 3) were enrolled. According to the mood severity, 34.48% of participants were classified as normal, 24.14% as moderate, and 41.38% as severe symptoms (p < 0.001). Peripheral BDNF was similar between the different mood severity groups (p > 0.05). No correlation between BDNF and HDRS and BDNF and HARS was detected regardless of the severity of mood symptoms (p > 0.05). Different from what has been observed in depressive disorders, independence between peripheral BDNF levels and mood symptoms in CUD was observed. This finding suggests a singular, intricate regulation of peripheral BDNF and mood as part of CUD-related maladaptations that might disrupt the expected antidepressant response and perpetuate mood symptoms in CUD.