[Personality changes in opioid-dependent subjects in a methadone maintenance treatment program]

Personality disorders and particularly antisocial personality disorders (APD) are quite frequent in opioid-dependent subjects. They show various personality traits: high neuroticism, high impulsivity, higher extraversion than the general population. Previous studies have reported that some but not all personality traits improved with treatment. In a previous study, we found a low rate of APD in a French population of opioid-dependent subjects. For this reason, we evaluated personality traits at intake and during maintenance treatment with methadone. Methods - The form A of the Eysenck Personality Inventory (EPI) was given to opioid addicts at intake and after 6 and 12 months of methadone treatment. Results - 134 subjects (96 males and 38 females) took the test at intake, 60 completed 12 months of treatment. After 12 months, the EPI Neuroticism (N) and the Extraversion-introversion (E) scale scores decreased significantly. The N score improved in the first 6 months, while the E score improved only during the second 6 months of treatment. Compared to a reference group of French normal controls, male and female opioid addicts showed high N and E scores. Demographic data and EPI scores of patients who stayed in treatment for 12 months did not differ significantly from those of dropouts (n=23). Patients with a history of suicide attempts (SA) started to use heroin at an earlier age and they showed a higher E score and a tendency for a higher N score at intake. Discussion - The two personality dimensions of the EPI changed during MMT, and the N score converged towards the score of normal controls. Opioid addicts differ from normal controls mostly in their N score. The EPI did not help to differentiate 12-month completers from dropouts. Higher E scores in patients with an SA history might reflect a higher impulsivity, which has been linked to suicidality in other patient groups.