Background & aim: Borderline Personality Disorder is one of the most important health problems of people with undesirable consequences on family councils. The aim of the present study was to compare the executive function and difficulties in emotion regulation in addicted with upper and lower borderline personality traits.

Methods: The present causal-comparative study included all male drug abusers who had been referred to addiction treatment centers. 80 addicts were selected by accessible sampling method and using a borderline personality traits (STB). Then, they were divided into two groups of 40 people for drug addicts in high and low. Using The Wisconsin Card Sorting Test and the scale of difficulty in the emotional regulation was conducted on two groups. Statistical data using multivariate analysis of variance MANOVA and LSD test were analyzed.

Results: The results indicated that compared to drug addicts with high borderline traits, the ones with low borderline traits had lower performance in Wisconsin Card Sorting Test  and the number of perseveration errors (p = 0.018) and total error (p = 0.002) was higher. Moreover, addicts with high borderline traits varied significantly higher scores in difficulty in emotional regulation (p=0.002) of the drug with low borderline personality traits.

Conclusion: The results indicated that addicts with high borderline traits, had weaker performance in executive function and higher levels of difficulty with emotional regulation. This may be due to neurological effects of drug addiction on their performance which leads to poorer performance compared with drug people with low borderline traits.