Copyright 2000 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.2000
We appreciate the thoughtful comments of Drs Weissman and Wickramaratne on our recently published article.1 The number of onsets for major depression (MD) in our sample falling into each decade were: younger than 10 years, 75; ages 10 to 19 years, 452; ages 20 to 29 years, 613; ages 30 to 39 years, 421; ages 40 to 49 years, 171; and ages 50 to 59 years, 22. In our sample, 11% of affected individuals (n=193) reported an age at onset (AAO) of after 40 years. Thoughts of death had a modest negative correlation with AAO (−0.10) and a stronger relationship with long duration (0.20) and impairment (0.12). We analyzed AAO as a continuous measure, with decade as a unit for ease of interpretation. Therefore, the hazard rate of 0.85 means that the baseline hazard rate was reduced (multiplied) by a factor of 0.85 for every 10-year increase in AAO. We thought this was easier to interpret than the 1-year change in hazard rate.
Kendler KS, Gardner CO, Prescott CA. Age of Onset and Familial Risk in Major Depression. Arch Gen Psychiatry. 2000;57(5):511. doi: