Effects of long-term benzodiazepine medication. A prospective cohort study: Methodological and clinical aspects

Benzodiazepine (BDZ) drug impact on mental functions was explored in a cohort study of 30 psychiatric outpatients on long-term BDZ medication. A new questionnaire, the Drug Impact on Mental Processes (DIMP) was used and evaluated. The patients were rated three times: on inclusion in the study, after about 18 months and, finally, only a few days later. Test–retest reliability was evaluated for the two last ratings and was found acceptable for 19/23 items. The DIMP scores indicated negative effects on crisis reaction, intensified defence mechanisms and reduced cognitive, emotional and conative functions. Long-term BDZ treatment intensified passive coping. The drug impact on mental functions ranged between a mild and a moderate degree. The clinical outcomes of the patients’ psychiatric disorders were evaluated at a 1-year follow-up after continued or discontinued BDZ treatment. In the subgroup that had discontinued the BDZ treatment at follow-up, significantly more patients reported reduced severity of their...