Omega-3 Polyunsaturated Fatty Acid (PUFA) Status in Major Depressive Disorder With Comorbid Anxiety Disorders

Background: Although lower levels of omega-3 polyunsaturated fatty acids (PUFAs) are found in major depressive disorder, less is known about PUFA status and anxiety disorders. Method: Medication-free participants with DSM-IV-defined major depressive disorder (MDD), with (n=18) and without (n=41) comorbid DSM-IV anxiety disorders, and healthy volunteers (n = 62) were recruited from October 2006 to May 2010 for mood disorder studies at the New York State Psychiatric Institute. Participants were 18-73 years of age (mean age, 35.8 +/- 12.6 years). Depression and anxiety severity was assessed using depression and anxiety subscales from the 17-item Hamilton Depression Rating Scale. Plasma PUFAs eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) and the ratio of arachidonic acid (AA; 22:4n-6) to EPA (AA:EPA) were quantified. This secondary analysis employed analysis of variance with a priori planned contrasts to test for diagnostic group differences in log-transformed PUFA levels (logDHA, logEPA, and logAA:EPA). Results: Plasma levels of logDHA (F-2,F-118 = 4.923, P=.009), logEPA (F-2,F-118=6.442, P=.002), and logAA:EPA (F-2,F-118=3.806, P=.025) differed across groups. Participants with MDD had lower logDHA (t(118)=2.324, P=.022) and logEPA (t(118)= 3.175, P=.002) levels and higher logAA:EPA levels (t(118)=-2.099, P=.038) compared with healthy volunteers. Lower logDHA (t(118)= 2.692, P=.008) and logEPA (t(118)=2.524, P=.013) levels and higher logAA:EPA levels (t(118)=-2.322, P=.022) distinguished anxious from nonanxious MDD. Depression severity was not associated with PUFA plasma levels; however, anxiety severity across the entire sample correlated negatively with logDHA (r(p)= -0.22, P=.015) and logEPA (r(p)=-0.25, P=.005) levels and positively with logAA:EPA levels (r(p)=0.18, P=.043). Conclusions: The presence and severity of comorbid anxiety were associated with the lowest EPA and DHA levels. Further studies are needed to elucidate whether omega-3 PUFA supplementation may preferentially alleviate MDD with more severe anxiety. (C) Copyright 2013 Physicians Postgraduate Press, Inc.