When one has difficulty sleeping, the waking world seems opaque. On top of feeling tired and fatigued, those who experience sleep disturbances can be irritable and have difficulty concentrating. When one has more severe cases of insomnia, one also faces a higher risk of developing heart disease, chronic pain, hypertension, and respiratory disorders. It can even cause some to gain weight. 


Sleep disruptions can also have a major impact on one’s emotional well-being. A growing body of research has found that sleep disturbances and depression have an extremely high rate of concurrence, and many researchers are convinced that the two are biconditional—meaning that one can give rise to the other, and vice-versa. In fact, a paper that was published in Dialogues in Clinical Neuroscience concluded, “The link between the two is so fundamental that some researchers have suggested that a diagnosis of depression in the absence of sleep complaints should be made with caution.” The paper’s lead author, David Nutt—the Edmond J Safra chair in Neuropsychopharmacology at Imperial College London—found that 83% of depressed patients experienced some form of insomnia, which was more than double the amount (36%) of those without depression. 


Bei Bei, Dpsych, PhD, from the Monash School of Psychological Sciences in Clayton, Australia, said the inverse was true, as well: “If a person does not currently have depression but goes through extended periods of time with sleep disturbances or insomnia, the sleep disturbances can potentially contribute to a mood disturbance or to even more severe depression.”   


The Mechanisms Behind the Two Diseases 

The sleep-wake cycle is regulated by what is known as the circadian process. When working properly, the circadian process operates in rhythm with the typical cycle of a day. One gets tired as the light of the day fades and the body prepares for sleep, and one begins to awaken as it becomes light again. The internal mechanisms behind the circadian cycle involve a complex orchestration of the neurochemical and the nuerophysiological presided over by the hypothalamus. 


Depression, meanwhile, is a medical condition and a mood disorder. While there are several possible antecedents to depression, as genetic and environmental factors can lead to a depressive episode, the neurophysiological causes of depression pertain to a deficiency of chemicals in the brain that regulate mood: serotonin, dopamine, and norepinephrine.  


However, these neurotransmitters do far more than just regulate mood. They have also been found to be integral to sleep efficiency. Deficiencies in these brain chemicals can lead to disturbances in sleep, particularly REM sleep, and can also lead to more restlessness during typical times when one should be in bed. This can create a vicious cycle wherein the more severe one’s depression becomes, the more severe one’s insomnia becomes. The inverse can also true: The more severe one’s insomnia becomes, the more severe one’s depression becomes. 



Because these concurrent afflictions reinforce one another, medical professionals need to address both of them simultaneously for optimal treatment. In some cases, cognitive behavioral therapy for insomnia (CBT-I), which involves numerous non-drug techniques to induce sleep, can be utilized before resorting to the use of drugs with surprisingly good results. Several studies have shown CBT-I to be far more effective in treating insomnia or depression than antidepressants alone.  


Yet another promising, non-pharmacological treatment for insomnia uses a combination of light treatment and melatonin, a hormone that helps regulate the circadian process. Studies have routinely found that the usage of light therapy, in conjunction with antidepressant therapy, is superior to the usage of antidepressants alone when treating depression and insomnia. 


These studies demonstrate that it is important for medical professionals to take a more holistic approach when determining the proper course of treatment, and that the most effective treatment plans are tailored to both the individual patient and the patient’s concurrent illnesses. This holistic approach has been the guiding philosophy for the Integrative Center for Wellness since its inception.