Can sleep disturbance influence changes in mental health status? Longitudinal research evidence from ageing studies in England and Japan

Background: Little is known about the role of sleep disturbance in relation to changes in
depressive states. We used data obtained from the participants aged 65 and over in the
English Longitudinal Study of Ageing (ELSA, waves 4 and 5, N=3108) and the Japan
Gerontological Evaluation Study (JAGES, 2010 and 2013 sweeps, N=7527) to examine
whether sleep disturbance is longitudinally associated with older adults’ patterns of
depressive states.
Methods: We created four patterns of depressive states (non-case, recovered, onset,
repeatedly depressive) by combining responses to the measures (scoring four or more on
seven items from the Center for Epidemiological Studies Depression Scale for the ELSA
participants and scoring 5 or more for the Geriatric Depression Scale-15 for the JAGES
participants) obtained at the baseline and follow-up. Sleep disturbance was assessed through
responses to three questions on sleep problems. Age, sex, partnership status, household
equivalised income, alcohol and cigarette use, and physical function were treated as
confounders in this study. Additionally, information on sleep medication was available in
JAGES and was included in the statistical models.
Results: More ELSA participants were non-depressive cases and reported no sleep
disturbances compared with the JAGES participants. Findings from multinomial logistic
regression analysis showed that more sleep disturbance was associated with the onset group
in ELSA (RRR=2.37, 95%CI=1.44-3.90) and JAGES (RRR=2.41, 95%CI=1.79-3.25) as well
as the recovery (RRR=3.42, 95%CI=1.98-5.90, RRR=2.71, 95%CI=1.95-3.75) and
repeatedly depressed group (RRR=7.24, 95%CI=3.91-13.40, RRR=5.16, 95%CI=3.82-6.98).
Conclusions: Findings suggest that the association between sleep disturbance and depression
in older adults is complex