Eight studies were included. These included five randomised controlled trials (n=472) and three open label studies (n approximately 56).
Enhancement (three randomised controlled trials)
Two (n=113 and n=57) of the three randomised controlled trials reported no significant difference in remission and response rates between triiodothyronine and placebo. One randomised controlled trial (n=124) reported significantly higher response (70 per cent versus 50 per cent, p=0.02) and remission rates (59 per cent versus 38 per cent, p=0.02) in the triiodothyronine group. One study reported higher adverse event rates (palpitations, sweating, nervousness and tremor) in triiodothyronine compared to placebo groups; the other two studies reported no difference between groups.
Augmentation (two randomised controlled trials and three open-label studies)
The three open-label augmentation studies (number of completers 11, 19 and 25) reported response rates ranging from 35 per cent to 49 per cent (reported as 48 per cent in the table) and remission rates ranging from 25 per cent to 36 per cent. One randomised controlled trial (n=142) reported no statistically significant difference in response or remission rates between lithium and triiodothyronine, but reported significantly higher rates of withdrawals due to adverse event rates in the lithium group (23 per cent versus 10 per cent, p=0.028). One randomised controlled trial (n=36) reported no significant difference in treatment effect between triiodothyronine, lithium, triiodothyronine plus lithium and placebo. Treatment groups were small (n=8 to 10).