Blood homocysteine concentration and mood disorders with mixed features among patients with alcohol use disorder

Blood homocysteine concentration (BHC) is higher in patients with alcohol use disorder (AUD). Previous studies have found a relationship between depressive symptoms severity and BHC in AUD patients and recently some authors have found high BHC among patients with bipolar disorder, both during manic and depressive episodes and in euthymic state. However, BHC in patients with mixed mood episode has not yet been investigated. The aim of this study was to evaluate the BHC of patients with AUD and mixed mood episode.

A sample of AUD outpatients was assessed by Mini-International Neuropsychiatric Interview (MINI Plus): those with a DSM-IV-TR mood disorder with mixed features were included in the MIXED group (n = 45), whereas those without mood episode were gathered in the NO MOOD group (n = 23). Two subgroups, MIXMANIA and MIXDEPRESSION, were formed according to the prevalence of manic or depressive symptoms, assessed by Young Mania Rating Scale (YMRS), and Hamilton Rating Scale for Depression (HDRS). The Alcohol Use Disorder Identification Test (AUDIT) was used to appraise the AUD. BHC was determined by High-Performance Liquid Chromatography.

The MIXED group showed greater severity of both depressive (26.35 ± 9.96 vs. 4.77 ± 0.92; p < 0.001) and manic (22.35 ± 3.30 vs. 6.14 ± 1.12; p < 0.001) symptoms, and higher BHC (28.80 ± 11.47 vs. 10.83 ± 2.81; p < 0.001), than the NO MOOD group. BHC was strongly correlated to the HDRS, YMRS and AUDIT scores, just as HDRS was to YMRS, and AUDIT was to both HDRS and YMRS, in the MIXED group only (p < 0.001). The MIXDEPRESSION subgroup showed higher BHC than the MIXMANIA subgroup (Mdn = 42.96, IQR = 10.44 vs. Mdn = 19.77, IQR = 5.93; p < 0.001). A linear regression model conducted on the MIXED group found a significant predictive value for BHC of both HDRS (β = 0.560, t = 2.43, p = 0.026) and AUDIT (β = 0.348, t = 2.17, p = 0.044).

Depressive symptoms seem to be mainly implicated in the BHC elevation among patients with both mixed features mood disorder and AUD.