Neurocognitive functions in patients on buprenorphine maintenance for opioid dependence: A comparative study with three matched control groups

• Published in: Asian journal of psychiatry Vol. 53; p. 102181
• Main Authors: Saroj, Rajoo, Ghosh, Abhishek, Subodh, BN, Nehra, Ritu, Mahintamani, Tathagata, Rana, Devender K., Basu, Debasish
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2020
• Subjects: Buprenorphine; Cognitive dysfunction; Naltrexone; Opioid dependence; Opioid dependence; Buprenorphine; Naltrexone; Cognitive dysfunction
• ISSN: 1876-2018; 1876-2026
• DOI: 10.1016/j.ajp.2020.102181

•Neurocognitive functions of patients with opioid dependence on buprenorphine assisted treatment were compared with the group on naltrexone, current users and control.•Patients with active dependence had impaired working memory, learning, attention, psychomotor speed and flexibility.•Patients on buprenorphine had poorer cognitive speed and flexibility, sustained attention, and verbal working memory.•Poorer cognitive flexibility persisted in the buprenorphine group even after controlling for intellectual function, and other confounders. Neurocognitive dysfunction with buprenorphine has mixed evidence, with many confounding factors. We compared the neurocognitive functions in patients with opioid dependence on buprenorphine maintenance (Index Group; IG) with those on naltrexone (NG), opioid-dependent in early detoxification (OD), and healthy control (CG). The four groups were matched for age, sex, and years of education. Except for the healthy control group (CG; n = 30), the two other comparison groups had twenty participants each. Subjects with other substance use disorders, HIV infection, head injury, epilepsy, and severe mental illness were excluded. Cognitive tests consisted of Trail Making Tests (TMT-A & B), Digit Vigilance test (DVT), verbal and visual N-Back Test (NBT), Rey's Auditory Verbal Learning Test (RAVLT), Wisconsin Card Sorting Test (WCST), Controlled Oral Word Association Test (COWA), and Wechsler Adult Intelligence Scale (WAIS). IG performed significantly worse in TMT-B, DVT, verbal NBT, and WCST (non-perseverative error) than CG. When IQ was controlled for, significance persisted in TMT-B, a marker of poor cognitive flexibility. The OD showed significantly poorer performance than NG and CG in the TMT-A & B, visual and verbal NBT, DVT, and RAVLT. When compared to the IG, the performance of the OD was significantly poor in the TMT-A & B. IG performed worse than NG in TMT-B, and NG performed poorer (than CG) in RAVLT. Patients on medication-assisted treatment had significant cognitive impairment limited to fewer cognitive domains, however, the extent and severity were highest in the group with active opioid dependence.