UGT1A1 and Anxiety: One observational study including 107 Japanese patients with HIV-1 infection showed that those individuals who carried reduced function variants (*6 and *28) in UGT1A1 had higher median plasma DTG concentrations and were reported to have a significantly higher cumulative incidence of neuropsychiatric adverse events (defined as dizziness, headache, insomnia, restlessness, and anxiety) than those who carried normal alleles in UGT1A1.