Cognitive function in short- and long-term substitution treatment: Are there differences?

Abstract

Cognitive impairment in drug-dependent patients receiving methadone maintenance treatment has been reported previously, although the literature is limited and results remain controversial. Long-term effects under stable methadone maintenance treatment (MMT) and the possibility of improvement in cognitive performance during long-term substitution treatment have rarely been investigated. We performed a comparative study investigating differences in cognitive functions under short- and long-term methadone treatment to test the hypothesis that patients perform better under long- than under short-term MMT. Seventy-seven patients were assessed cross-sectional either at least 30 days after the start of MMT (short-term group, n=35) or after at least 6 months of MMT (long-term group, n=42) with a comprehensive neuropsychological test battery on intelligence, learning and memory, attention and executive functions. Urine screenings were performed immediately before neuropsychological testing to check for concomitant drug use. Our findings may suggest, with all due caution, a slightly better performance of the long-term group in executive functions and visuo-construction. No group differences were found in attentional functions and learning and memory. More longitudinal research and studies controlling for the effects of dosage and duration of opioid addiction are necessary to examine whether cognitive ability may improve under long-term MMT.

Stroop task among patients with obsessive-compulsive disorder (OCD) and pathological gambling (PG) in methadone maintenance treatment (MMT)

“…Studies on cognitive function of MMT patients usually describe them as suffering from cognitive impairment as reflected by their poor performance on diverse cognitive tasks 3 – 5 . Although some investigators have suggested that methadone itself might relate to their impairment, others also reported possible improvement in their cognitive abilities during MMT 6 , 7 …”

Drug interactions with dementia‐related pathophysiological pathways worsen or prevent dementia

“…In their review, Højsted et al () concluded that opioid treatment induced no effect or worsening of CF in cancer pain patients and had no effect or improvement in chronic non‐cancer pain patients. Soyka, Zingg, Koller, and Hennig‐Fast () performed a cross‐sectional study investigating opioid substitution treatment and showed that patients receiving long‐term methadone maintenance treatment (MMT; >6 months) had better performances in executive functions and visuo‐construction than patients receiving short‐term MMT. However, Wang, Wouldes, and Russell () showed that MMT is associated with cognitive impairment if the daily dose is higher than 60 mg. One cohort study performed by Dublin et al () assessed the association between opioid use and dementia.…”

Achievement of take-home dose privileges is associated with better-perceived sleep and with cognitive status among methadone maintenance treatment patients

“…As such, patients with privileges need to manifest at least a minimum level of cognitive performance suitable to fulfi l these responsibilities. Most of the many studies on the cognitive status of MMT patients, however, suggest that it is usually poor (Darke et al 2012;Marvel et al 2012; for see review Wang et al 2013), and only a few studies reported that improvement may occur during treatment (Soyka et al 2010;Bracken et al 2012).…”