Objective. Frequents cases (10—30% of the elderly population) of regular long-term use of anxiolytic and hypnotic drugs, in particular, benzodiazepines, without control of the physician is an urgent problem of medicine worldwide. Severe and irreversible cognitive impairment is a frequent and severe consequence of this use. Authors studied cognitive impairment in these cases. Material and methods. Patients were enrolled in the study from a psychiatric hospital. The study included 56 women, aged over 50 years, admitted to the hospital with the diagnosis of a mental disorder. Before admission, the patients regularly used benzodiazepines without a prescription for more than 2 months. Later on, anxiolytics were withdrawn during 1—5 days. The patients were studied during 4 weeks in the hospital. To assess the severity and dynamics of their condition, authors used MADRS, HAM-A, MMSE. Results and conclusion. Severe cognitive impairment, achieving the level of dementia, was found in 57.2% of the patients, mild or moderate of cognitive impairment was in 32.1% and only 10.7% had normal level of cognitive functioning. After 4 weeks of benzodiazepine withdrawal, the percentage of patients with dementia reduced to 21.4%, the severity of cognitive impairment was estimated as mild or moderate. A number of patients without cognitive impairment increased to 37.5%. The old age of patients was a significant negative predictor of the dynamics. An impact of the high anxiolytic dose was shown on trend level. The duration of a mental disorder and duration of uncontrollable consumption of anxiolytics and hypnotics did not exert an effect on the development and reversibility of cognitive impairment. A combination of anxiolytics with alcohol increased the risk of dementia and did not reverse the cognitive pathology.