Cannabis Use in MS Patients Linked to Higher Pain and Fatigue the Next Day | Research

The takeaway

Daily ecological momentary assessments in people with MS found that cannabis use predicted greater fatigue and higher momentary pain the following day, despite patients likely using cannabis to manage these very symptoms.

Neurologists treating MS, MS patients using cannabis for symptoms, rehabilitation specialists, and researchers studying cannabis in chronic neurological conditions.

What the researchers found

Cannabis use was associated with greater subsequent fatigue and higher momentary pain in MS patients, while alcohol and nicotine also predicted greater fatigue. In the reverse direction, higher average pain predicted reduced alcohol use and increased opioid use, revealing complex bidirectional symptom-substance dynamics.

Why it matters

Many MS patients use cannabis for symptom management, but this study reveals a paradox: cannabis may actually worsen the very symptoms (pain, fatigue) it's intended to treat, creating a self-reinforcing cycle.

The numbers in context

N=258; 14-day EMA periods at 3 timepoints; cannabis→increased fatigue; cannabis→increased momentary pain; caffeine→reduced fatigue; alcohol→reduced stress; opioids→increased average pain; bidirectional symptom-substance relationships

How the study worked

Secondary analysis of ecological momentary assessment data collected 4 times daily for 14 days at baseline, 1-year, and 2-year follow-ups from 258 ambulatory adults with MS, using mixed-effects logistic regression for lagged associations.

What this study cannot tell us

Secondary analysis; EMA self-report; dichotomous substance use (yes/no) misses dose information; 14-day windows may not capture longer patterns; ambulatory patients may not represent all MS severity levels; cannot rule out confounding by flare severity.

How to read the evidence

Well-designed EMA study with repeated within-person measurements and appropriate lagged analysis, providing granular daily evidence despite limitations of self-report and dichotomous substance measurement.

When this study was published

Published 2026; multi-year EMA follow-up.

The bigger picture

The finding that cannabis worsens next-day pain and fatigue in MS challenges its perceived therapeutic value in this population and has important implications for neurologist counseling.

Questions still open

Is the pain-worsening effect from cannabis rebound or from cannabis-related sleep disruption? Would CBD-only products show different effects? Should neurologists actively counsel against cannabis for MS symptom management?

Common questions

Does cannabis help with MS symptoms?

This daily-tracking study found the opposite — cannabis use predicted greater fatigue and higher pain the next day in people with MS, suggesting it may paradoxically worsen the symptoms patients use it to manage.

What substances affect MS symptoms most?

Cannabis was linked to worse pain and fatigue, while caffeine reduced fatigue. Alcohol reduced stress but increased fatigue. These daily patterns suggest MS patients need personalized guidance on substance use and symptom management.

Read the original research

Daily Temporal Associations Between Use of Psychoactive Substances and Fatigue, Pain, Stress, and Depressive Symptoms in People with Multiple Sclerosis.

Archives of physical medicine and rehabilitation

View on PubMed ↗Publisher’s paper ↗

Citation

Kim, Jeeyeon; Ehde, Dawn M; Alschuler, Kevin N; Fritz, Nora E; Kratz, Anna L. (2026). Daily Temporal Associations Between Use of Psychoactive Substances and Fatigue, Pain, Stress, and Depressive Symptoms in People with Multiple Sclerosis.. Archives of physical medicine and rehabilitation. https://doi.org/10.1016/j.apmr.2026.01.014