Affiliations 

  • 1 a Postdoctoral Associate, Department of Psychiatry , Yale School of Medicine , New Haven , CT , USA
  • 2 c Associate Professor, School of Social Sciences , Universiti Sains Malaysia , Gelugor , Penang , Malaysia
  • 3 d Associate Research Scientist, Department of Psychiatry , Yale School of Medicine , New Haven , CT , USA
  • 4 e Medical Lecturer, School of Medical Sciences , Universiti Sains Malaysia , Kota Bharu , Kelantan , Malaysia
  • 5 f Professor, Department of Psychiatry , Yale School of Medicine , New Haven , CT , USA
  • 6 g Professor, Centre for Drug Research , Universiti Sains Malaysia , Gelugor , Penang , Malaysia
  • 7 h Associate Professor, Department of Psychiatry , Yale School of Medicine , New Haven , CT , USA
J Psychoactive Drugs, 2017 06 29;49(4):326-332.
PMID: 28661714 DOI: 10.1080/02791072.2017.1342152

Abstract

Amphetamine-type stimulants (ATS) use is increasingly prevalent in Malaysia, including among individuals who also use opioids. We evaluated cognitive functioning profiles among individuals with co-occurring opioid and ATS dependence and their lifetime patterns of drug use. Participants (N = 50) enrolling in a clinical trial of buprenorphine/naloxone treatment with or without atomoxetine completed the Raven's Standard Progressive Matrices, Rey-Osterrieth Complex Figure Test, Digit Span, Trail Making and Symbol Digit Substitution tasks. Multidimensional scaling and a K-means cluster analyses were conducted to classify participants into lower versus higher cognitive performance groups. Subsequently, analyses of variance procedures were conducted to evaluate between group differences on drug use history and demographics. Two clusters of individuals with distinct profiles of cognitive performance were identified. The age of ATS use initiation, controlling for the overall duration of drug use, was significantly earlier in the lower than in the higher cognitive performance cluster: 20.9 (95% CI: 18.0-23.8) versus 25.2 (95% CI: 22.4-28.0, p = 0.038). While adverse effects of ATS use on cognitive functioning can be particularly pronounced with younger age, potentially related to greater vulnerability of the developing brain to stimulant and/or neurotoxic effects of these drugs, the current study findings cannot preclude lowered cognitive performance before initiation of ATS use.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.