Insomnia disorder appears to play a causal role in the development of new stressful life events, especially “dependent” events for which individuals are at least partly responsible, said the investigators of an ongoing longitudinal study of people who have experienced involuntary job loss.
The “stress-generation hypothesis” has been applied for several decades in the context of depression. It posits that depressed individuals generate more stressful life events – events that create family conflict or disrupt careers, for instance – than individuals who are not depressed.
The new analysis of individuals with involuntary job loss suggests that the same can be said of insomnia. “Insomnia disorder is associated with fatigue, daytime sleepiness, impaired concentration, and difficulties in emotional regulation,” Iva Skobic, MSPH, MA, a PhD student at the University of Arizona, Tucson, said at the virtual annual meeting of the Associated Professional Sleep Societies.
“These may lead to impaired decision-making, interpersonal conflicts, difficulty meeting deadlines and keeping commitments, and other sources [of stressful life events],” she said. “This extension of the stress-generation hypothesis has important implications for harm reduction interventions for insomnia disorder.”
Investigators conducted a cross-lagged panel analysis using baseline and 3-month follow-up data from 137 individuals who completed a standardized, textual life event measure called the Life Events and Difficulties Schedule after having lost their jobs involuntarily. Participants were interviewed and their events were rated for severity by a consensus panel using operationalized criteria. The analysis employed linear regression controlling for covariates (age, gender, and race) and logistic regression that controlled for insomnia at baseline. Insomnia disorder was defined as meeting-2/3 criteria using the Duke Structured Interview for Sleep Disorders.
The findings: Insomnia disorder at baseline predicted the number of stressful life events (either dependent or interpersonal) generated within 3 months (beta, 0.70; standard error, 0.31; Tscore, 2.27; P = .03). Conversely, the number of stressful events at baseline did not predict insomnia (odds ratio, 0.97; 95% confidence interval, 0.73-1.29). There also was a trend toward increased generation of dependent events specifically among those with insomnia disorder.
Participants were a mean age of 42 years, and all had been in their previous place of employment for at least 6 months. Nearly 60% met the diagnostic threshold for insomnia at baseline. They were part of a larger ongoing study examining the linkages between job loss and sleep disturbances, obesity, and mental health – the Assessing Daily Activity Patterns through Occupational Transitions (ADAPT) study, supported by the National Heart, Lung, and Blood Institute.
This analysis on insomnia was completed before the COVID-19 pandemic began, but it and other analyses soon to be reported are highly relevant to the economic climate, said, principal investigator of ADAPT and a coauthor of the insomnia study, in an interview after the meeting.
Insomnia is a frequent comorbidity of depression and shares many of its symptoms, from increased fatigue to emotional dysregulation and an increased risk of maladaptive coping strategies. “Interestingly, the literature on the stress-generation hypothesis posits that these very symptoms are on the casual pathway between depression and stressful life events,” said Ms. Skobic at the meeting.
In commenting on the study, Krishna M. Sundar, MD, medical director of the Sleep-Wake Center at the University of Utah, Salt Lake City, noted that the analysis did not include any measure of the severity of insomnia. Still, he said, “finding an association [with stress generation] at [just] 3 months with the presence of insomnia disorder is quite interesting.”
There were higher rates of insomnia in the sample than depression, Dr. Haynes said, but the analysis did not control for depression or take it into account.
“We know [from prior research] that stress clearly leads to insomnia. The big [takeaway] here is that insomnia can also lead to more stress,” she said. “It’s important to think of it as a reciprocal relationship. If we can potentially treat insomnia, we may be able to stop that cycle of other stressful events that affect both [the individuals] and others as well.”
Ms. Skobic had no disclosures.