Short-term prognosis of depression in adults with Down's syndrome: association with thyroid status and effects on adaptive behaviour.

Findings for Down's syndrome adults with depression were compared to those for non-depressed Down's syndrome controls. Mean age of onset of depression was 30.1 years, the majority of subjects were female and biological more so than psychotic symptoms were presenting features. No statistically significant association between depression and thyroid dysfunction was found. For the depressed group, scores for level of adaptive functioning were significantly lower and those for maladaptive behaviour significantly higher. At one-year follow-up, although some improvement was found, the majority of depressed subjects were still symptomatic. The short-term prognosis for depression in adults with Down's syndrome appears to be poor but possibly better the earlier the age of onset.