Depression
This study evaluated depression using a Korean form of the
Geriatric Depression Scale (KGDS). The KGDS is a tool
that was developed by translating the Geriatric Depression
Scale (GDS) developed by Yesavage et al. (1983) into
Korean, after which it was modified and complemented by
Jung et al. (1997) in order to measure the severity of depression
in the elderly. It is composed of 30 items with 5 subdomains,
namely emotional instability, pessimistic thoughts
and unhappiness, physical weakness and decreased vitality,
decline in cognitive function, and decreased social interest
and activities. It uses dichotomous questions, 1 or 0 point
being given for each answer, resulting in a total score from 0
to 30. The higher the score, the more severe is the depression.
The Cronbach’s a of the original tool was 0.94 and its correlation
with the Hamilton Rating Scale for Depression was
r = 0.84 (P < 0.001). Cronbach’s a of KGDS was 0.88 with
Korean subjects, which demonstrates that the tool used in this
study is both valid and reliable.