Despite different treatment approaches many drug addicted patients continue to use drugs during and after treatment.

Personality traits are considered risk factors for drug use, and, in turn, the psychoactive substances impact individuals’ traits.

To describe the sample of 186 opioid addicted patients entered hospital treatment and assessing the differences in personality traits between abstinent and non-abstinent after one year.

A cohort of 186 patients consecutively admitted to the detoxification unit was investigated. The research interview, the Big Five Inventory (BFI), the Treatment Outcomes Profile (TOP) were administered during the first week of admission to the detoxification unit. Urine test was administered on the day of admission and at each follow-up point in combination with the TOP (after three, six and twelve months). Illicit drugs abstinence during one year after intake was selected as a treatment outcome measure.

Twelve months after admission 82 (44.9%) patients abstained completely. Agreeable patients remain in treatment longer (r = 0.20, P = 0.07). Extraversion and openness are negatively correlated with abstinence after six and twelve months (r = –0.15, P = 0.041; r = –0.15, P = 0.044). Neuroticism is in negative correlation with duration of treatment (r = –0.20, P = 0.006). Patients who are less open to new experiences are more likely to abstain from drugs 6 months after admission (r = –0.17, P = 0.021).

Personality measured with BFI correlates with treatment outcome poorly. At the same time personality could have an important role in responding to treatment, but personality traits could be at the same time protective as well as risk factors.

The authors have not supplied their declaration of competing interest.