Cognitive performance of opioid maintenance vs. abstinence

brains! (Photo credit: cloois)


A new study finds lower cognitive functioning in maintenance patients compared with abstinent former users. It also found no difference between methadone patients and buprenorphine patients.



To compare the cognitive performances of maintenance patients (MAIN), abstinent ex-users (ABST) and healthy non-heroin using controls (CON).


Case control study of 125 MAIN (94 subjects maintained on methadone, 31 on buprenorphine), 50 ABST and 50 CON. Neuropsychological tests measuring executive function, working memory, information processing speed, verbal learning and non-verbal learning were administered.


There were no differences between the cognitive profiles of those maintained on methadone or buprenorphine on any administered test. After controlling for confounders, the MAIN group had poorer performance than controls in six of the 13 administered tests, and were poorer than the ABST group in five. The MAIN group exhibited poorer performance in the Haylings Sentence Completion, Matrix Reasoning, Digit Symbol, Logical Memory (immediate and delayed recall), and the Complex Figure Test (immediate recall). There were no differences between the ABST and CON groups on any of the administered tests.


Poorer cognitive performance, across a range of test and domains, was seen amongst maintenance patients, regardless of their maintenance drug. This is a group that is likely might benefit from approaches for managing individuals with cognitive and behavioural difficulties arising from brain dysfunction.




Methadone’s cognitive effects


English: Methadone structure, animation
English: Methadone structure, animation (Photo credit: Wikipedia)

Another study on methadone’s cognitive effects:

In one study, on the day after the last exposure to methadone, there was a significant reduction (around 70 per cent) in the level of a signal molecule which is important in learning and memory, in both the hippocampus and in the frontal area of the brain. This reduction supports findings from a previous study (Andersen et al., 2011) where impaired attention in rats was found at the same time. At this time, methadone is no longer present in the brain. This indicates that methadone can lead to cellular changes that affect cognitive functioning after the drug has left the body, which may be cause for concern.

The study was done on rats, not people, but it’s findings aren’t isolated.

Patients and their loved ones may decide that the potential benefits outweigh the costs, but they should be made aware of the costs and know the alternatives.