Cognitive function among methadone assisted treatment patient in Malaysia.

Background: The use of non-medical opioids has reached 60 million in 2021. Methadone-assisted treatment (MAT) is a widely used harm-reduction strategy for opioid addiction. However, methadone can cause cognitive impairment, which can impede treatment.

Methods: This cross-sectional study was conducted between July 1st and July 31, 2023. A total of 114 participants, comprising 76 MAT patients and 38 healthy subjects (controls), were recruited. Sociodemographic questionnaire, DSM-5 and neuropsychiatric cognitive (NUCOG) assessments were used. A general linear model was used to examine cognitive function between the MMT and control groups while controlling for all possible confounders.

Results: The MAT group performed significantly lower on the NUCOG total score (p < .001) and visuoconstructional (p < .001), memory (p < .001), executive (p = .016), and language (p < .001) scores than the control group. No significant differences were found between the groups in terms of the attention score (p = .457). Adjusted confounders included age, education level, income, and marital status.

Conclusions: Patients on MAT demonstrated cognitive impairment, particularly in the visuoconstructional, memory, executive, and language domains, compared to the control group. However, there are confounding factors that needs to be addressed in order to come with better treatment and intervention strategies.