Dietary supplement use in people being treated for depression

The use of dietary supplements has increased over the past 10 years, with up to 50% of adults being reported to have taken dietary supplements. The types of supplements taken are often related to physical morbidities. However, information about their use in combination with prescription drugs is lacking. In particular, there is little information on the use of supplements by people with depression. Our aim was to examine the use of dietary supplements by people being treated for depression. Seventy-two participants who were being treated for depression in the community were recruited for a clinical trial to determine the effect of fish oil on mood in the treatment of depression. The results of the primary analysis are reported elsewhere. Exclusion criteria included any co-existing psychiatric disorder (except anxiety disorders), blood clotting disorders, unstable medical conditions, and those taking fish oil supplements. Demographic information, details about the participants' depression and current therapies, use of dietary and herbal supplements in the previous 12 months, and physical activity data were collected at baseline. Characteristics of supplement users were compared with those of non-users using either chi-square or Mann-Whitney U tests. Forty-five (63%) of 72 participants who provided dietary supplement information had taken at least one dietary supplement within the previous 12 months. On average, supplement users were found to have taken 2.8 (SD=1.56) dietary supplements during the assessment period. Women were more likely to be taking supplements than men (P<0.001). In conclusion, the use of dietary supplements is common among people being treated for depression. This has important implications for clinical practice as little is known about supplement-drug interactions.