Our findings in this study should also be interpreted in light of the specific measures used to assess for the constructs of interest. Symptoms of the three psychiatric syndromes assessed in the MIDUS study, MDD, GAD, and PD, were measured with the CIDI-SF (Kessler et al., 1998). This is a well-validated measure that shows good sensitivity and specificity in comparison to the full Composite International Diagnostic Interview (Kessler et al., 1998). It is, however, a lay-administered diagnostic interview that may not adequately capture the presence of absence of a symptom in the same way that a clinician or more extensive inventory might. Further, the stem-branch structure of the interview may result in failing to capture the presence of associated symptoms in the absence of depressed mood or anhedonia. However, given that the stem questions—which must be endorsed to trigger assessment of the other symptoms—are the defining features of the disorders (i.e., DSM requires depress mood or anhedonia for a diagnosis of depressive episode), the CIDI-SF is most likely capturing the true variation in the internalizing syndromes as they exist in
