background Although there are theoretical grounds for using hormone therapy to treat depressive symptoms in patients with hypothyroidism, the clinical evidence for this is unclear.
objective To investigate the efficacy of treating depression with thyroid hormone in a population with subclinical hypothyroidism.
method Literature search in various databases for double-blind randomised placebocontrolled studies that provided clinical evidence for the effect of thyroid hormone on depressive symptoms in a population with subclinical hypothyroidism.
results Three randomized controlled trials (rcts) were included. None of these was concerned primarily with patients suffering from depressive disorder, but focused mainly on subjects with subclinical hypothyroidism, with the score on the depressive scale as secondary outcome. In all the studies selected subclinical hypothyroidism was treated with levothyroxine which had no beneficial effect on depression.
conclusion Since there is a lack of evidence of beneficial effects in a population with subclinical hypothyroidism and a lack of research into the effects in a depressive population, no definite answer can yet be given to the question posed in the title.