There's increasing real evidence -- not just anecdotal -- for the bio-psychosocial relationship between stress, insomnia and depression, and the recurring, circular nature of these three unhealthy and unhappy states of mind and body. Not a shock for patients who suffer from insomnia or for the medical professionals who treat them, but important news in creating an environment to ramp up research and treatment options for insomnia.
Our friend and colleague Chris Drake was lead investigator for an important research program on insomnia and stress that was published in the journalSleep* recently. Chris is director of the Sleep Research Laboratory at Henry Ford Hospital, and a top-notch scientist. Chris' research supports the likelihood of the link between insomnia and our reactions to, and perceptions of, ongoing stress.
In particular, Chris' study looks at something new: how "cognitive intrusions" also seem connected to insomnia. Cognitive intrusions are those pesky, repetitive, unwanted thoughts about the stressful situation that you just can't seem to turn off. In addition, the study reports that "sleep reactivity" -- how likely your sleep will be affected negatively by stress -- is also highly associated with insomnia. As the report notes, "Cognitive intrusion and sleep reactivity remained significant independent predictors of insomnia."** Further, the study notes, "Our results suggest that sleep reactivity may represent a common vulnerability to both disorders [i.e., insomnia and depression], and further that insomnia mediates [i.e., brings about] the association between sleep reactivity and depression."***
So stress and the inability to turn it off combine with sleep reactivity level to increase insomnia, which in turn leads to depression. And that, of course, means more stress. And less sleep. This is a cycle that "just keeps on going and going," a lot like that battery-operated pink bunny, but not nearly as much fun.
No wonder insomnia is challenging for both patient and doctor!
Further, as Chris points out, "We're still trying to answer the question, 'What are the mechanisms by which insomnia evolves into depression.' Once we determine these mechanisms we can target insomnia interventions much more effectively and efficiently."
In the meantime, as a clinician who sees a lot of insomnia patients, I am enthusiastic about Chris and his team's impressive, data-rich research. It fuels a deeper, richer investigation of insomnia and moves us closer to better ways to practice medicine to help insomnia patients. For my part, I see the prospect of the sleep medicine community moving toward clearer categories of insomnia and important examinations of the associations between insomnia and a range of psychiatric disorders.
One of my patients, a 56-year-old male who presented with "difficulty sleeping" is an illustrative case for the tie between psychiatric issues and insomnia.
My patient reported "years of inability to get sleep" as well as "lots of stress." His primary issue was sleep initiation -- being able to get to sleep. While the patient had bad sleep habits -- sleep hygiene -- that was not the only challenge. Discussion with him and his wife revealed that the patient was drinking "18 beers per night to help me get to sleep." His wife also reported that the patient was irritable, frequently distracted and "gets frustrated easily." She also reported that the patient snored.
This is definitely not-so-simple insomnia.
As we tested and further examined the patient, we determined he had undiagnosed anxiety disorder which he was self-medicating with alcohol. The patient was indeed an alcoholic, but in addition, a sleep study showed severe sleep apnea.
We treated the patient with alcohol counseling and sleep behavior counseling, and prescribed antidepressants as well as a CPAP (continuous positive airway pressure) device for the sleep apnea. The outcome is that our patient experienced normalization of his anxiety and depression, his sleep improved markedly and consequently his daily life and functioning improved as well.
This is a case where it seems clear that long-term stress and anxiety caused chronic insomnia which led to ever-increasing levels of alcohol consumption, exacerbated by severe sleep apnea. But the hard truth is that we physicians and scientists do not really know how psychological and emotional states provoke insomnia, or how insomnia evolves into depression and other psychological disorders. And the more we know the larger our arsenal will be to help our patients combat insomnia.
There are exciting prospects before us, so stay tuned for more compelling data and treatment strategies in the battle against insomnia.
* "Stress and Sleep Reactivity: a Prospective Investigation of the Stress-Diathesis Model of Insomnia," Christopher L. Drake, PhD; Vivek Pillai, PhD; Tomas Roth, PhD of the Sleep Disorders and Research Center, Henry Ford Hospital, Detroit, MI; journal SLEEP, Vol. 37, No. 8, 2014
** Drake et. al., p. 1299
*** Drake et. al. p. 1302