Background: Drug abuse has a high co-morbidity with mental disorders. This study investigated the personality trait of IV drug abusers to clarify the importance of psychological intervention.

Materials and Methods: All IV heroin abusers of Kashan prison (73 cases) were enrolled to this cross sectional study in 2006, and their demographic data and MMPI test were recorded and evaluated. The results were statistically analyzed using Fisher Exact Test.

Results : Six of 73 of abusers were excluded from this study for their invalid test results. Out of 67 cases 17 (25.38%) did not have any disorder and 50 (74.62%) were suffering from abnormal personality traits based on MMPI profile. The mean age of participants was 29.86 ± 6.41. Forty three (64.18%) were under 30, and 24 (35.82%) were above 30 years old. Thirty five were single and 32 married. There was a significant relationship between abnormal personality traits and educational level (PV<0.001, OR=10.1). Prominent personality traits were anti-sociality in 12 (24%), depression in 10 (20%), hypomania in 7 (14%), hypochondria in 5 (10%), hysteria in 5 (10%), anxiety in 4 (8%), paranoid in 4 (8%), and schizoid in 3 (6%).

Conclusion : Anti-sociality and depression are the frequent traits among IV drug abusers. Younger victims are at higher risk. Also, low educational level can predict abnormal personality trait. Therefore, multimodal treatment interventions, especially psychotherapy have a great role on treatment of these patients.