Recent research highlights that abstaining from cannabis for 28 days can lead to significant cognitive improvements and changes in brain activation among people with multiple sclerosis (MS). This study, presented by Omar Iqbal Khan, MD, emphasises the potential benefits of cannabis abstinence on the default mode network (DMN), which plays a crucial role in modulating cognition.

Study Overview

The study focused on individuals with multiple sclerosis who were frequent cannabis users:

• Participants: 33 cognitively impaired individuals with MS (pwMS) who used cannabis frequently over many years.
• Groups: Participants were divided into two groups:
  • Cannabis Continuation (CC): 15 individuals continued using cannabis.
  • Cannabis Withdrawal (CW): 18 individuals abstained from cannabis for 28 days.
• Assessments: Neuropsychological assessments and functional MRI (fMRI) scans were conducted at both baseline and after 28 days.
• Compliance: Cannabis withdrawal compliance was monitored through regular urine testing.

Key Findings

Cognitive Improvements

The cannabis withdrawal group exhibited significant improvements in multiple cognitive domains by the end of the 28-day period. These improvements underscore the potential cognitive benefits of abstaining from cannabis for individuals with MS.

Brain Activation Changes

The study utilised resting state fMRI (rs-fMRI) data processed using independent component analysis (ICA) to identify the DMN spatial map. Key findings included:

• No Baseline Differences: At baseline, there were no significant differences between the CC and CW groups in DMN activation.
• Day 28 Differences:
  • CW Group vs. CC Group: By day 28, the CW group showed increased activation in the left posterior cingulate and right angular gyrus (p < 0.05 for both, TFCE).
  • Within CW Group: The CW group exhibited increased activation at day 28 versus baseline in the left posterior cingulate, right angular gyrus, left hippocampus (BA 36), and right medial prefrontal cortex (p < 0.05).

Implications for the Default Mode Network (DMN)

The DMN is known to modulate cognition, and the study revealed enhanced DMN activity following cannabis abstinence. This finding provides objective evidence supporting the cognitive benefits of abstaining from cannabis for individuals with MS.

Summary

The study concluded that abstaining from cannabis for 28 days can reverse the activation of DMN activity and lead to improved cognition across several domains in people with MS. These findings offer valuable insights for counselling patients with MS and cognitive complaints about the potential benefits of cannabis abstinence.

Source: PracticeUpdate