Cannabis and multiple substance abuse raise the serum concentrations of the neurotrophins NGF and BDNF in drug-naïve schizophrenic patients

Neurotrophic factors are known to play a crucial role in growth, differentiation and maintenance of function in neurons during development and adult life. In schizophrenic patients a deficiency of nerve growth factor (NGF) with respect to neurodevelopment was postulated (1). We examined serum-NGF concentrations in 109 drug-naïve schizophrenic patients and found normal NGF concentrations compared to controls (n=61) when no substance abuse prevailed, but significantly raised NGF with associated former cannabis or multiple substance abuse. This possibly represents an endogenous repair mechanism of damaged neurons in vulnerable brains (2). Likewise we examined 130 sera of drug-naïve schizophrenics for BDNF and again found differences between the groups. We thus concluded that neurotrophins may play a role in the origin and outcome of schizophrenia at least with respect to drug intake.

1. Aloe L et al.: Beh Pharmacology 2000.11:235–242.

2. Jockers-Scherübl MC et al.: J Psychopharmacology, in press.