Reduced serum levels of brain-derived neurotrophic factor in adult male patients with autism

Background: The precise mechanisms underlying the pathophysiology of autism are currently unknown. Given the key role of brain-derived neurotrophic factor (BDNF) in brain development, we hypothesized that BDNF may play a role in the pathophysiology of autism. In this study, we studied whether serum levels of BDNF are altered in patients with autism. Methods: We measured serum levels of BDNF in 18 adult male patients with autism and 18 age-matched healthy male control subjects. Results: The serum levels of BDNF in patients with autism (25.6 +/- 2.15 ng/ml (mean +/- S.D.)) were significantly (z=-4.42, p < 0.001) lower than those of normal controls (61.6 +/- 10.9 ng/ml (mean S.D.)). Nevertheless, we found no correlations between BDNF levels and clinical variables in autistic patients. Conclusions: This study suggests that reduced BDNF levels may play a role in the pathophysiology of autism. (c) 2006 Elsevier Inc. All rights reserved.