Substance use disorder is a growing phenomenon among old adults. It is usually significantly undervalued, misidentified, under diagnosed and poorly treated. It has been related to cognitive impairment but there are few studies focused on the elderly.

To evaluate the relationship between drug use and cognitive impairment in old adults.

We conducted a prospective study (basal and 6 month follow up) in 67 patients over 65 years old seeking for treatment for drug misuse (alcohol and prescription drugs, mainly benzodiacepines) in addiction and dual diagnosis unit in Barcelona. A specific protocol was performed to evaluate attention, executive function, working memory, learning capacity, fonetic and visual fluency, decision-making, visual construction and cognitive flexibility (FCT, CPT-II, N-BACK, COWAT FAS, TAP, SDMT, IGT, CVLT, TOL, RFFT, STROOP). Patients were compared with a control group (healthy non drug users) with same characteristics (gender, age range and education status). The protocol consisted in two separated sessions of 90 minutes each one performed by a neuropsychologist.

Results obtained suggested that patients under drug misuse had worse scores in fluency, visual construction, memory and attention compared with controls. After 6 month treatment and achieving abstinence patients improve in cognitive skills as verbal learning, short-term memory and free recall of verbal information. Cognitive impairment profile changes depending on the substance abused (alcohol or benzodiacepines).

Drug use can produce deleterious effects in old adults. However, those who achieve abstinence may improve some cognitive functioning as verbal learning, short-term memory and free recall of verbal information.

The authors have not supplied their declaration of competing interest.