Antioxidant defense in schizophrenia and bipolar disorder: A meta-analysis of MRS studies of anterior cingulate glutathione.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational case-control neuroimaging studies
PubMed 30125624 · doi:10.1016/j.pnpbp.2018.08.006
What was done
Authors conducted a systematic review and random-effects meta-analysis of 1H-MRS studies published up to June 2018. They assessed anterior cingulate cortex (ACC) glutathione (GSH) levels in patients with DSM- or ICD-diagnosed schizophrenia, schizoaffective disorder, or bipolar disorder compared against healthy control (HC) groups. Meta-regression of moderator variables was also performed.
What was found
Across 18 included studies (578 patients and 581 healthy controls total): - Schizophrenia vs. HC: 13 studies showed a small but statistically significant reduction in ACC GSH (random-effects standardized mean difference [SMD] = 0.26, 95% CI [0.07 to 0.44], p = 0.008; heterogeneity p = 0.11). - Bipolar disorder vs. HC: 6 studies showed a significant increase in ACC GSH (random-effects SMD = -0.28, 95% CI [-0.09 to -0.47], p = 0.003; heterogeneity p = 0.95).
Why it matters
This study provides evidence that schizophrenia and bipolar disorder have diverging patterns of redox abnormalities in the anterior cingulate cortex, suggesting distinct pathophysiology involving glutathione regulation.
Limits
The primary studies were observational cross-sectional imaging datasets with small individual sample sizes. There was insufficient published data to evaluate the moderating effects of specific clinical symptom profiles, illness stages, or medication effects.
Cited by
- supports Glutathione levels are low in serious mental illness.