Brain-Derived Neurotrophic Factor and Oxidative Stress in Cannabis Dependence

Neurotrophin levels and oxidative stress markers such as ceruloplasmin and free thiols have been shown to contribute to pathophysiology in several psychiatric disorders.

Our aim is to evaluate whether those markers are altered in cannabis dependence.

Forty-five cannabis-dependent patients diagnosed according to the DSM-IV criteria and 45 healthy controls matched according to sex, age, BMI, and smoking status were enrolled. Brain-derived neurotrophic factor (BDNF), ceruloplasmin, lipid hydroperoxide, and total free thiols were measured in both groups. Those who had psychiatric comorbidities were excluded before sampling.

We found significantly increased BDNF, ceruloplasmin, and lipid hydroperoxide, and decreased free thiol levels in patients with cannabis dependence. There is also a positive correlation between BDNF and lipid hydroperoxide (n = r = 0.472, p < 0.001) and a negative correlation between BDNF and total thiols (n = r = -0.412, p = 0.001).

Increased BDNF might be a sign of impaired neuronal plasticity that is crucial for memory formation and adaptive response to drug addiction. Neuronal plasticity in the ventral tegmental area dopaminergic neurons was implied to play a role in substance addiction disorders, and these adaptations can be secondary to oxidative stress. Our findings, including increased lipid hydroperoxide, ceruloplasmin, and decreased free thiols, might support this hypothesis. In conclusion, cannabis dependency alters BDNF levels and increases oxidative stress.