Insomnia, depression, and physical disorders in late life: a 2-year longitudinal community study in Koreans.
OBJECTIVE
To investigate prevalence, incidence, and persistence of insomnia, and their bidirectional longitudinal associations with depression and physical disorders.


METHODS
A community based longitudinal study.


METHODS
Elders living in private households in South Korea.


METHODS
1204 people > or = 65 years of age were evaluated at baseline; 909 of them (75%) were re-interviewed after 2 years.


RESULTS
Insomnia was defined as difficulty in initiation or maintenance of sleep > or = 3 nights per week over the last month. Diagnosis of depression (Geriatric Mental State) and number of physical disorders were ascertained. Sociodemographic and clinical covariates included age, gender, education, housing, past occupation, current employment, living area, life events, social deficit, physical activity, cognitive impairment, anxiety, and daily drinking. Of those (27%) with insomnia at baseline, 40% had insomnia at follow-up. Of those without insomnia at baseline, 23% had insomnia at follow-up. Baseline depression was significantly associated with prevalence and incidence of insomnia. Baseline number of physical disorders was significantly associated with prevalence, incidence, and persistence of insomnia. Baseline insomnia was independently associated with incident depression and an increase in reported physical disorders.


CONCLUSIONS
Insomnia was common and often persistent in this population. Insomnia was closely and reciprocally related to depression and physical disorders.
Kim
Jae-Min
JM
Department of Psychiatry & Depression Clinical Research Center, Chonnam National University Medical School, Kwangju, Korea.
Stewart
Robert
R
Kim
Sung-Wan
SW
Yang
Su-Jin
SJ
Shin
Il-Seon
IS
Yoon
Jin-Sang
JS
D000368:Aged; D000375:Aging / Q000523:psychology; D015897:Comorbidity; D003866:Depressive Disorder / Q000453:epidemiology* / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000379:methods* / Q000706:statistics & numerical data; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007723:Korea / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D016017:Odds Ratio; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012111:Residence Characteristics; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology* / Q000523:psychology*