Black CN, et al. – The aim of the present study was to explore the relationship of plasma uric acid, the greatest contributor to blood antioxidant capacity, with major depressive disorder (MDD) and anxiety disorders. This large scale study suggested that plasma uric acid levels were lower in current major depressive and anxiety disorders and it was negatively correlated with symptom severity and duration. However, lowered antioxidant status could play a role in affective disorders.

Methods

• Information were from the Netherlands Study of Depression and Anxiety incorporating patients with current (N=1648), remitted (N=609) MDD and/or anxiety disorders (of which N=710 antidepressant users) and six hundred eighteen controls.
• Diagnoses were established with the Composite International Diagnostic Interview.
• After that, symptom severity was surveyed with the Inventory of Depressive Symptoms-Self Report, Beck Anxiety Inventory and Fear Questionnaire.
• In addition, uric acid was measured in plasma.
• Finally, analyses were adjusted for sociodemographic, health and lifestyle variables.

Results

• Researchers reported that plasma uric acid adjusted mean levels were lower in current MDD and/or anxiety disorder(s) (289μmol/l) compared to remitted disorders (298μmol/l, p<0.001; Cohen's d 0.10).
• However, this finding was independent of antidepressant use.
• They observed that depressive (β-0.05, p=0.0012), anxiety (β-0.04, p=0.009) and phobic (β-0.03, p=0.036) symptom severity, and symptom duration (β-0.04, p=0.009) were negatively correlated with uric acid.