Authors: (including presenting author): :
Chan MH(1), Choi YS(1), Chan KS(1), Lee WK(1), Chin YM(1)
Introduction: :
Cognitive impairments are common among patients with SUD. Substances like stimulants, hypnotics and cannabis may alter brain function resulting in deficits in executive function, memory, and attention. Cognitive impairments are associated with poorer treatment outcomes and daily functioning. The prevalence of cognitive impairments in patients with SUD is estimated to be between 30% to 80% in previous studies (Bruijnen et., 2019). However, local data remain unclear.
Methodology: :
A retrospective study was carried out between 2023 and 2025 in PYNEH. Patients with SUD under care of occupational therapy department of PYNEH were recruited using convenience sampling. Patients’ sociodemographic information and substance abuse history were collected. Primary problem substance was used during the analysis. Subtests of the MATRICS Consensus Cognitive Battery (MCCB) were administrated to assess the cognitive function of the participants. Cognitive impairment was defined as T-score below 40 (< 1 SD) in any cognitive domains in MCCB. Participants’ work functioning was based on their employment status while economically inactive participants were excluded during the analysis related to work functioning.
Result & Outcome: :
148 patients were recruited with mean age of 42.7. 68.2% were male. 54.7% were unemployed. 80.4% had dual diagnosis. 67.6% had polysubstance abuse. The three most common primary problem substances were methamphetamine (32.4%), hypnotics (20.9%) and cough mixture (17.6%). The prevalence of cognitive impairments was 67.6%. The prevalences of impairments in different domains were 48.6% (verbal learning), 35.1% (working memory), 31.1% (visual learning), 16.9% (speed of processing), 15.5% (attention/vigilance) and 14.9% (reasoning and problem solving). The prevalences of cognitive impairments in different substances were 84.6% (emerging drugs including cannabis, etomidate and nitrogen oxide), 71.4% (heroin), 70.0% (ketamine), 69.2% (cough mixture), 66.7% (methamphetamine), 64.5% (hypnotics) and 53.8% (cocaine). The unemployment rate of participants with cognitive impairments was significantly higher than those without cognitive impairments (OR=2.58, p=0.011). No significant differences in cognitive function were found between participants with and without dual diagnosis, nor with and without polysubstance abuse (p>0.05). In conclusion, the prevalence of cognitive impairments was high in patients with SUD in HKEC, especially for those abusing new emerging drugs. Cognitive impairments might pose a higher risk of unemployment. The results provided evidence on the need of cognitive training and work rehabilitation for patients with SUD. Reference:
Bruijnen, C. J. W. H., Dijkstra, B. A. G., Walvoort, S. J. W., Markus, W., VanDerNagel, J. E. L., Kessels, R. P. C., & DE Jong, C. A. J. (2019). Prevalence of cognitive impairment in patients with substance use disorder. Drug and alcohol review, 38(4), 435–442. https://doi.org/10.1111/dar.12922
