The aim of the present cross-sectional study is to examine the plasma concentrations of BDNF, IGF-1 and IGFBP-3 in a cohort of abstinent cocaine users on an outpatient basis according to cocaine use history (duration of use, length of abstinence and cocaine symptom severity) and the comorbidity of other mental disorders. The gene discussed is IGFBP3; the disease is psychiatric disorder.