Depression, isotretinoin, and folic acid: A practical review.

Isotretinoin (ISO) is a first-generation retinoid discovered in 1952 and approved by the FDA for the treatment of nodulocystic acne in 1982. The anti-inflammatory properties of ISO have found its use in disorders other than acne. ISO can create psychiatric problems, including depression and suicidal ideation. These neuropsychiatric problems are very similar to disorders secondary to hyperhomocysteinemia (HHcy), vitamin B12, and folic acid (vitamin B9) deficiencies. Given that previous literature suggested folate supplementation improved the efficacy of traditional antidepressant medications, clinicians may wish to consider folate supplementation for patients with depression or possible depressive symptoms, such as acne patients with genetic susceptibility. Brain-derived neurotrophic factor may be a cytokine-specific screening biomarker in immune-based antidepressive therapy.