Table 1. Summary of depression metrics used to determine depression status and age at onset within the NCDS sample.

Wave	Age (year)	Depression Measure	Number of reported cases (% female)	Number of new cases (% female)
5	33 (1991)	Age at which depression was first a problem	390 (79.0%)	390 (79.0%)
6	42 (2000)	Age first started feeling depressed	1466 (66.1%)	1085 (61.5%)
7	46 (2004)	ICD codes for medical disorders and self reported age at onset. F32, 33 and 34	101 (62.3%)	24 (37.5%)