How Are Depression And Insomnia Related?

With over 300 million people worldwide estimated to live with depression, it has been labeled the leading cause of disability. This number may seem alarming when considering the symptoms accompanying depression, including difficulty caring for oneself and the possibility of suicidal thoughts. 

One common symptom of depressive disorders is insomnia, which can cause difficulty falling or staying asleep. Disturbed sleep can grow more distressing with time and significantly impact a person’s quality of life. In the United States, scientists estimate that 40% of Americans may live with insomnia at one point in their life. In contrast, an estimated 17.3 million US adults may experience the symptoms of depression at least once a year. 

Depression and insomnia are often considered interrelated disorders due to the high percentage of people who have insomnia and depressive episodes concurrently. To understand the interrelationship of insomnia and depressive disorders, learning to identify symptoms and find ways to receive professional support may be valuable. 

The cycle of insomnia and depression

Approximately 75% of individuals with depression experience sleep disturbances from insomnia, suggesting that the two conditions often appear in tandem. A further 40% of those with depression also have hypersomnia—a condition characterized by excess sleep. Various factors influence the relationship between the two but are commonly categorized into two groups: 

Some researchers theorize that the combination of the two creates a cycle of sleeping difficulties and depressive symptoms that may be difficult to break.

What is the cause of insomnia? 

Below are a few potential causes of insomnia and how they might be related to depressive disorders. 

As a symptom of depression 

According to Harvard Health, 69% of people with insomnia also struggle with depression following a disturbed sleep pattern cycle. In another study, 21% of individuals reported that they experienced a combination of hypersomnia and insomnia.

These two studies suggest that depressive episodes may cause insomnia or hypersomnia. Some individuals feel depressed at night, hindering them from experiencing healthy sleep. Insomnia due to depression may occur due to several connections with the condition, including but not limited to the following: 

• Side effects of medication for depression 
• A lack of motivation for sleep hygiene 
• Less exercise or movement during the day 
• Using the bed for non-sleep activities
• Poor eating 
• Missing work or school
• A lack of routine 

Experts in a UK study note that depressive disorders without insomnia or other sleep disorders are increasingly rare. For that reason, insomnia is often used as diagnostic criteria for depression and is listed as an official symptom in the DSM-5. 

Disturbances in sleep regulation

Over the past 35 years, research has determined the existence of two sleep regulation mechanisms, including the circadian and homeostatic (recovery) processes. The systems work together to maintain sleep consistency and the need for sleep after wakeful periods. 

The circadian process is the mechanism that drives individuals to sleep consistently. In individuals without sleep disorders, the circadian process begins around 11 pm and peaks at 4 am, fading around waking hours. The recovery process also drives sleep but directly depends on the time since an individual last slept. 

The difference is that the circadian process controls sleep at relatively set times each night. The recovery process may drive an individual to sleep inconsistently if they have spent too much time without sleep. This mechanism drives the body’s need for a midday nap after an individual stays awake for the entire night.

In individuals without insomnia, these two mechanisms may interact consistently for seven to eight hours each night, from around 11 pm to 6 am. The brain activity that controls these processes is called slow-wave activity and shows up most prevalently at the onset of sleep. In individuals who do not have sleep disorders, slow-wave brain activity helps them fall asleep quickly and easily. It also aids them in staying asleep for the entire night. 

Those with depression and sleep disorders often have disrupted circadian and homeostatic processes. In these individuals, slow-wave activity is much lower. Therefore, the drive to sleep may be reduced for individuals with depression and insomnia. This disruption in sleep processes is why insomnia is much more common than hypersomnia in individuals with depressive disorders. 

Effects of prescription medications

Some people with depression take antidepressant prescription medication to control their symptoms. While medication may be helpful to combat mood shifts, lethargy, and other symptoms of depression, it may also induce or worsen the symptoms of sleep disorders, especially insomnia. 

There are two primary types of medication geared towards those with depression: medication with “activating” properties and medication with “sedative” properties. Medication with activating effects often activates energy levels and raises the moods of those with depression. Sedative medications might control the moods of those with bipolar disorder and relieve anxiety. 

Activating medication can make an individual feel more alert and reduce the urge to sleep at consistent intervals. Sedative medication may have the opposite effects, causing an increased need to sleep. These medications may not wear off until later in the day, causing people to sleep late. 

Consult your medical provider before starting, changing, or stopping a medication. A provider can offer further guidance on how a medication may impact you and how to reverse these side effects if you have insomnia or hypersomnia as a result. 

Antecedent insomnia 

In the UK study above, while 68% of individuals with depression described their insomnia symptoms as appearing at or after their depressive disorder began, 16% reported that their sleep challenges began before they experienced changes or shifts in mood. 

While this is a minority category, some people with insomnia may develop depression as a result. Studies often describe situations in which people with insomnia will have an increased risk of developing symptoms of depressive disorders. Due to this research, depression could be categorized as a symptom of insomnia. For younger adults and middle-aged individuals with prior depressive episodes, insomnia provides a two to four-time increased risk of a relapsed depressive episode later in life.

In addition, researchers have posited that complaints of episodes of insomnia almost every night for two weeks or more could be a useful indicator to predict a major depressive episode for those who have a history of depressive disorders. Other studies show that 14% of individuals with insomnia develop a new case of major depressive disorder a year after onset. 

How is insomnia connected to mood changes? 

Besides disturbed sleep patterns, mood changes and lethargy can occur due to insomnia and depression. People with sleep disorders may experience more significant emotional dysregulation than those without, as sleep is essential for wellness and mental health. 

Insomnia is linked to a reduced quality of life, as it can enhance anxiety, frustration, hopelessness, exhaustion, and difficulty concentrating. Some studies have researched how different age groups are affected by insomnia and other sleep disorders, discovering that many symptoms of insomnia coincide with symptoms of depression. These findings suggest that those struggling with insomnia may experience similar symptoms to depression, even if they don’t have a depressive disorder.

In the same study, researchers found that adolescents with sleep disorders had an increased risk of decreased performance in school as well as an increased risk of self-harm and suicidal ideation. Insomnia has been shown to cause decreased quality of life, mortality, inflammation, and a greater risk for chronic diseases in adults. 

These impairments may significantly lower an individual’s ability to concentrate, be self-motivated, perform at work or school, initiate projects, or solve problems. The daytime impairments that individuals struggling with insomnia face may lead to low self-esteem and a decreased quality of life. These two factors could increase the chances of anxiety and depression. 

Professional support for insomnia and depression

While there is a studied link between depression and insomnia, it may be difficult to determine if sleep disorders present as a precursor to depression or are caused by depression. The two conditions often co-occur, and the focus on these conditions may be better aimed at treating both simultaneously than working to prevent one or the other. One way to treat these symptoms is therapy. 

At times, the stress of finding a therapist and traveling to appointments may keep some people from reaching out for help. In these cases, online therapy through a platform like BetterHelp may be beneficial. Online therapy allows clients to meet a provider from home and choose a time slot that fits their schedule, allowing individuals to work around sleep disturbances. In addition, clients can choose between phone, video, and live chat sessions with their therapists. 

Research has also shown that online therapy is a highly effective method for receiving mental healthcare compared to in-person therapy. For example, a study published in Sleep Medicine Clinics examined the efficacy of internet-based cognitive-behavioral therapy (iCBT) in treating insomnia. Researchers found that in tailoring CBT sessions specific for people with chronic insomnia, people had significant improvement in symptoms and a reduced need for pharmacological interventions.