A Systematic Review and Meta-Analysis of Cognitive Performance among People with Chronic Use of Opioids for Chronic Non-Cancer Pain

Abstract

Objective Opioids, often prescribed for chronic non-cancer pain, may adversely affect cognition. Research has not been synthesised in recent years, during which time academic interest has increased. This study presents meta-analyses on cognitive performance in people taking opioids for CNCP. Methods We ran systematic literature searches in EMBASE, Medline, and PsycINFO. Eligible studies included people taking opioids for CNCP and an opioid-free group (i.e., case-control) or session (e.g., pre-post), and objective cognitive assessments. Using random-effects meta-analyses, we computed pooled effect sizes for differential task performance for each study design across five domains (motor performance, attention, working memory, executive functions, memory). Results Seventeen studies were included. Case-control studies covered 3 control types (healthy, CNCP, taper-off). Pre-post studies were grouped into 5 follow-ups (4–6 and 6–9 weeks; 3, 6, and 12 months). Effect sizes ranged from 0.02–0.62. Cases showed small magnitude impairments in attention and memory compared with healthy controls. Although limited by small sample sizes, there was no clear evidence of impairment in cases compared with opioid-free controls with CNCP. Cases showed some cognitive improvements from opioid-free baseline to follow-up. Effects were strongest for attention and working memory, and were apparent from 4 weeks to 6 months follow-up. Other effects were small and non-significant. Conclusions Opioid therapy for CNCP did not worsen cognitive performance and improved it for some domains. People who take opioids for CNCP may evidence deficits in attention and memory, but this is unlikely to translate to global impairment and likely relates to pain more so than opioids.

Self-perceived cognitive function and neuropsychological performance in women with fibromyalgia

“…On the other hand, opioid therapy for chronic non-cancer pain does not affect cognitive performance and even improves it in certain domains. Attention and memory deficits are probably more pain-related than opioid use 41 .…”

Patients’ self‐reported physical and psychological effects of opioid use in chronic noncancer pain—A retrospective cross‐sectional analysis

“…'Difficulty with mental activities' and 'poor memory' are described by 23% and 17% of the patients of this survey, respectively. The correlation between chronic opioid use and cognition is still inconsistent in the literature despite a large body of research; whereas some reviewers describe minimal or no significant impairment in cognitive functioning (Akhurst et al, 2021;Ersek et al, 2004), others found reduced attention, vigilance, working memory and psychomotor speed (Allegri et al, 2019;Jamison & Edwards, 2013) depending on the characteristics of the opioid (e.g. the chemical structure, formulation, dosing, treatment phase: beginning or steady state, comedication of anti-depressants/anti-epileptic drugs) or the patient (e.g.…”