Testing homocysteine-induced neurotransmitter deficiency, and depression of mood hypothesis in clinical practice

Methods: two-hundred and thirty-six hospitalised acutely ill older patients, who were part of a randomised double-blind placebo-controlled trial, were assigned to receive daily mixed oral nutritional supplements containing B-group vitamins or a placebo for 6 weeks. Outcome measures included symptoms of depression measured using Geriatric Depression score and plasma tHcy levels. Results: the mean tHcy concentration fell by 22% among patients given the supplements compared with the placebo group (mean difference 4.1 mu mol/l (95% CI: 0.14-8.03), P = 0.043). tHcy concentrations was divided into four quartiles and analysed against depression scores. tHcy concentrations in the first relative to the fourth quartile of the distribution were associated with a lower depression symptoms at the end of the supplement period (Geriatric depression score r = -0.20, P = 0.042). Conclusions: lower plasma tHcy concentrations were associated with reduced depression symptoms in older patients recovering from acute illness.