Recent research on the obsessive-compulsive disorder (OCD) has emphasis on the moderating effects of the brain behavioral mechanisms.

The main purpose of this research was to examine the Gray's brain behavioral systems (1994) among the obsessive-compulsive disordered patients.

My aim of this research was to examine the Gray's brain behavioral systems (1994) among the obsessive-compulsive disordered patients.

Participants were included 20 obsessive-compulsive patients and 20 normal individuals who were selected respectively by available sampling and counter balance sampling methods on the basis of the age, sex and education variables. The average of participant's ages was 29/85 (SD = 7/37). All subjects were completed the Gray-Wilson Questionnaire and data were extracted for the three systems of BAS, BIS and FFS and also for its six measures of approach, active avoidance, passive avoidance, extinction, fight and flight separately.

A multivariate analysis of variance, for comparing six measures of the Gray-Wilson questionnaire were shown significantly differences for Behavioral Activation System (BAS) and also for Behavioral Inhibition System (BIS). Pairwise comparisons were shown a higher Behavioral- Inhibition system (BIS) and a lower Behavioral- Activation system (BAS) in obsessive -compulsive patients than normal individuals. No significant difference was found for Fight- Flight system (FFS).

These results were suggested higher BIS and lower BAS activity as moderator of OCD. This results supported the reinforcement sensitivity theory (RST) conveying a higher tendency to the punishment and elimination of the reward in anxious person as a consequence of Behavioral-Inhibition System (BIS).