Cognitive effects of labeled addictolytic medications.

INTRODUCTION: Alcohol, tobacco, and illegal drug usage is pervasive throughout the world, and abuse of these substances is a major contributor to the global disease burden. Many pharmacotherapies have been developed over the last 50years to target addictive disorders. While the efficacy of these pharmacotherapies is largely recognized, their cognitive impact is less known. However, all substance abuse disorders are known to promote cognitive disorders like executive dysfunction and memory impairment. These impairments are critical for the maintenance of addictive behaviors and impede cognitive behavioral therapies that are regularly administered in association with pharmacotherapies. It is also unknown if addictolytic medications have an impact on preexisting cognitive disorders, and if this impact is modulated by the indication of prescription, i.e. abstinence, reduction or substitution, or by the specific action of the medication.

METHOD: We reviewed the cognitive effects of labeled medications for tobacco addiction (varenicline, bupropion, nicotine patch and nicotine gums), alcohol addiction (naltrexone, nalmefene, baclofen, disulfiram, sodium oxybate, acamprosate), and opioid addiction (methadone, buprenorphine) in human studies. Studies were selected following MOOSE guidelines for systematic reviews of observational studies, using the keywords [Cognition] and [Cognitive disorders] and [treatment] for each medication.

RESULTS: 971 articles were screened and 77 studies met the inclusion criteria and were reported in this review (for alcohol abuse, n=21, for tobacco n=22, for opioid n=34. However, very few comparative clinical trials have explored the chronic effects of addictolytic medications on cognition in addictive behaviors, and there are no clinical trials on the cognitive impact of nalmefene in patients suffering from alcohol use disorders.

DISCUSSION: Although some medications seem to enhance cognition in patients suffering from cognitive disorders, others could promote cognitive impairments, and our work highlights a lack of literature on this subject. In conclusion, more comparative clinical trials are needed to better understand the cognitive impact of addictolytic medications.