This study compared the cognitive performance of opioid maintainance clients, abstinent ex-users of opioids, and healthy, non-heroin using controls.
Professor Skye McDonald (School of Psychology, UNSW)
Recent years have seen growing interest in cognitive impairment amongst opiate users. Evidence of the extent and nature of these deficits remains unclear, and this study aimed to provide a detailed profile of the nature and extent of deficits.
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 insix 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 to benefit from approaches for managing individuals with cognitive and behavioural difficulties arising from brain dysfunction.
Links to these papers are below under 'Publicatons':
Darke, S., McDonald, S., Kaye, S. & Torok, M. (2012) Comparative patterns of cognitive performance amongst opioid maintenance patients, abstinent opioid users and non-opioid users. Drug and Alcohol Dependence, 126, 309-315.
Darke, S, McDonald, S., Kaye, S. & Torok, M. (2012) Prevalence and correlates of traumatic brain injury amongst heroin users. Addiction Theory and Research, 20, 522–528.
McDonald, S., Darke, S., Kaye, S. & Torok, M. (2013) Deficits in social perception in opioid maintenance patients, abstinent opioid users and non-opioid users. Addiction, 108 (3), 566-574.
Novel data on the cognitive impairment seen amongst opioid users, that may be helpful in improving the treatment of such individuals.