Generalizability of pharmacologic and psychotherapy trial results for late-life unipolar depression

Objectives: Despite evidence of low representativeness of clinical trial results for depression in adults, the generalizability of clinical trial results for late-life depression is unknown. This study sought to quantify the representativeness of pharmacologic and psychotherapy clinical trial results for late-life unipolar depression.

Method: Data were derived from the 2004-2005 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a nationally representative sample of 34,653 adults from the United States population. To assess the generalizability of clinical trial results for late-life depression, we applied a standard set of eligibility criteria representative of pharmacologic and psychotherapy clinical trials to all individuals aged 65 years and older in NESARC with a DSM-IV diagnosis of MDE and no lifetime history of mania/hypomania (n = 273) and in a subsample of individuals seeking help for depression (n = 78).

Results: More than four of ten respondents and about two of ten respondents would have been excluded by at least one exclusion criterion in a typical pharmacologic and psychotherapy efficacy trial, respectively. Similar results (i.e.41.1% and 25.9%, respectively) were found in the subsample of individuals seeking help for depression. Excess percentage of exclusion in typical pharmacologic studies was accounted for by the criterion "significant medical condition". We also found that populations typically included in pharmacologic and psychotherapy clinical trials for late-life unipolar depression may substantially differ.

Conclusion: Psychotherapy trial results may be representative of most patients with late-life unipolar depression in routine clinical practice. By contrast, pharmacologic clinical trials may not be readily generalizable to community samples.