A bidirectional relationship between anxiety and depression, and insomnia? A prospective study in the general population.
OBJECTIVE
The purpose of this study was to examine whether there is a bidirectional relationship between, on one hand, anxiety and depression and, on the other hand, insomnia over the course of a year.


METHODS
A randomly selected sample of 3000 participants from the general population filled out a baseline survey (N=1812) and a 1-year follow-up survey (N=1498) on anxiety, depression, and insomnia.


RESULTS
On cross-sectional analyses, bivariate correlations showed that anxiety, depression, and insomnia were significantly intercorrelated (varphi=.31-.54). On prospective analyses, logistic regression analyses demonstrated that anxiety at baseline [odds ratio (OR)=4.27 (8% of variance)] and depression at baseline [OR=2.28 (2% of variance)] were related to new cases of insomnia on follow-up. Furthermore, insomnia at baseline was related to new episodes of high anxiety and high depression on follow-up [OR=2.30 (2% of variance) and OR=3.51 (4% of variance), respectively].


CONCLUSIONS
Evidence suggests that there is a bidirectional relationship between, on one hand, anxiety and depression and, on the other hand, insomnia. This suggests that anxiety, depression, and insomnia are intertwined over time, implying implications for theoretical conceptualizations and interventions.
Jansson-Fröjmark
Markus
M
Department of Behavioral, Social, and Legal Sciences, Orebro University, Orebro, Sweden. markus.jansson@bsr.oru.se
Lindblom
Karin
K
D000328:Adult; D001007:Anxiety / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology*; D013548:Sweden