The Link Between Insomnia and Mental Illness

Insomnia rates have continued to rise throughout the pandemic, contributing to increasing rates of depression and anxiety, as well as worsening symptoms of other severe mental illnesses. Defined as chronic sleep onset and/or sleep continuity problems associated with impaired daytime functioning, insomnia has a bidirectional relationship with mental health issues. 

Mental Illness and Insomnia: How Do They Interact?

The incidence of psychiatric illness in patients with insomnia is estimated to be near 50 percent. The highest comorbidity rates have been noted in mood disorders, including depression and bipolar disorder, as well as anxiety disorders. In patients with diagnosed major depressive disorder, as many as 90 percent struggle with insomnia. 

Insomnia has also been identified as a risk factor for the development of a mental illness. In a meta-analysis of patients with insomnia published in 2011, the authors concluded that persistent insomnia can more than double the risk of major depression. 

Another 2019 meta-analysis of more than 130,000 participants assessed the effects of baseline insomnia on the development of a psychiatric illness over a five-year period. Individuals with insomnia demonstrated a significantly higher risk of alcohol abuse and psychosis. Additionally, insomnia tripled the likelihood of being diagnosed with a depressive or anxiety disorder.

Sleep disturbances can also worsen symptoms of diagnosed mental illness, including substance abuse, mood, and psychotic disorders. Laskemoen and colleagues found that a startling 74 percent of participants with diagnoses of schizophrenia or bipolar spectrum had at least one type of sleep disturbance (insomnia, hypersomnia, or delayed sleep phase)—nearly twice the rates in healthy controls. Importantly, compared to those with mental illness not suffering from sleep disturbances, sleep-disordered participants had more severe negative and depressive symptoms on the positive and negative syndrome scale (PANSS), as well as significantly lower function as measured by global assessment of functioning (GAF).

How Can Insomnia Be Treated?

Although insomnia symptoms can resolve after relief from a particular life stressor, as many as 50 percent of patients with more severe symptoms will have a chronic course. Many of the sedative-hypnotics are designed for short-term use, though are frequently continued beyond the recommended time frame. In a survey reviewing the national use of prescription drugs for insomnia, as many as 20 percent of individuals use a medication to target insomnia in a given month. 

The benefits of cognitive-behavioral therapy for insomnia (CBT-I) have been demonstrated repeatedly, and it is recommended as the first-line treatment for insomnia by the Clinical Guidelines of the American Academy of Sleep Medicine, Center for Disease Control , and the National Institute of Health . Studies suggest benefits persist long-term, even after completing the therapy sessions have ended.