ABSTRACT
Based on the reinforcement sensitivity theory normal and non-normal personality are located along a continuum. This study amid to the compare activity of brain/behavioral systems and mental health in addicts and normal individuals based on Jeffrey Gray theory. This research was a kind of cross-sectional research that was performed in 2009. Fifty addicts [opium 26, heroin 18 and cocaine 6] and 50 normal subjects chosen by at hand sampling method and based on age, sex, and educational level matched. In this research of Gray-Wilson personality questionnaire and depression, anxiety, Stress scales were used. Data were analyzed by t-test in independent groups. The results showed that there is a significant difference between normal and addict's individuals in both behavioral activation system and behavioral inhibition system [P>0.05], but there isn't a significant difference in fight/flight system [P>0.05] and also there is a significant difference between depression, anxiety and Stress in normal and addict's individuals [P>0.05]. The results of this study conform to basic hypotheses of reinforcement sensitivity theory Gray and psychological condition of addict's individuals