Up to two-thirds of patients in addiction treatment have cognitive deficits
STUDY: Li W et al, Life 2026
STUDY TYPE: Systematic review
FUNDING: Health Resources and Services Administration
Background
Addiction programs rarely test cognition, yet these problems impair functioning and as well as insight, self-control, and sobriety.
The Review
- 20 studies from nine countries, mostly cross-sectional, plus three randomized trials and one non-randomized trial. Studies were not pooled.
- Included alcohol, opioids, stimulants, cannabis, tobacco, and inhaled petrol.
Results
Rates of impairment ranged from 23% to 65%, depending on the population and test. Every substance was linked to deficits in at least one area:
- Alcohol: memory, reaction time, and impulse control
- Tobacco: executive attention in heavy smokers
- Methamphetamine: attention, working memory, and mental flexibility
- Inhaled petrol (gasoline): learning and spatial awareness
- Multiple substances: the worst deficits overall, especially verbal memory and attention
Longer use predicted worse performance. Problems with executive functioning included less insight into substance problems and less motivation to seek treatment. In an Israeli cohort, better cognitive scores predicted abstinence, employment, and fewer relapses.
Abstinence helped. After six months off methamphetamine, attention, processing speed, and flexibility improved. Among polysubstance users, longer abstinence predicted better recall.
Treatment results were mixed. Patients on methadone or buprenorphine improved modestly in concentration and executive function after 8 to 10 weeks. Cognitive remediation improved working memory and executive function in a randomized trial of 48 veterans.
Limitations
Most studies were small and cross-sectional, and few controlled for head injury, depression, or education.
Practice Implications
- Screen for cognition with the ThincIt app or Montreal Cognitive Assessment (MoCA). The MMSE was less sensitive in this review. Retest every six months.
- Sustained abstinence is the best route to improvement; lifestyle changes including exercise, diet, and sound sleep may help.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
