Melatonin And Depression: How A Lack Of Sleep Can Cause Depressive Symptoms

Those who have experienced a sleepless night or other sleep related issues may be able to affirm the uncomfortable side effects of sleep deprivation, including irritation, fatigue, stress, and an inability to concentrate. While one night of sleeplessness may produce short-term effects that are resolved after your sleep cycle and circadian rhythm are returned to the norm, continued instances of sleep trouble may lead to more severe issues. 

The inability to fall or stay asleep is known as insomnia. Those who struggle with chronic, long-term insomnia may be at risk of developing other mental health challenges like anxiety, stress, short-term depression, or depressive disorders. These mood conditions can also give rise to sleep disorders, which can make the link between melatonin and depression challenging to discern.

Are there links between depression and melatonin? 

The effect of melatonin deficiency, which may lead to insomnia, can also cause symptoms of depression, such as low moods, anxiety, unstable emotions, and difficulty with academic or professional performance. Many individuals with depression also experience insomnia. These symptoms can make depression worse or cause a relapse. 

Much of an individual's sleep cycle is managed by the hormone melatonin, found in the brain's pineal gland. During waking hours, melatonin levels are low. However, as it becomes time to enter the sleep phase, optic nerves in the eyes send information to the pineal gland to begin producing melatonin, the increased melatonin promotes sleepiness. Those who do not produce sufficient melatonin struggle to sleep at night, and some may develop insomnia. For these individuals finding ways to create more melatonin may be helpful in returning to a more normal sleep cycle. 

In the brain, a group of cells called the suprachiasmatic nucleus controls the sleep-woke cycle and functions as the pacemaker for sleep. Within the sleep-wake cycle, or circadian rhythms, sleep should occupy about a third of the day, or about seven hours per night, according to the Centers for Disease Control. Sleeping less than seven hours continually may lead to mental and physical health complications, including depression, anxiety, and physical health challenges. 

According to the Sleep Foundation, those who experience insomnia are ten times as likely to have clinical depression and 17 times more likely to have clinical anxiety. As episodes of insomnia increase in quantity and severity, the chances increase. Those with acute and chronic insomnia are much more likely to develop depressive symptoms than those who do not experience sleep deprivation.

Acute vs. chronic insomnia

Acute insomnia is defined as short-term insomnia. It may be brought about by stressful situations at work or school, family influences, or traumatic events in an individual's life. Acute insomnia only lasts for a couple of days or weeks. If acute insomnia extends beyond a month, it is labeled as chronic insomnia.

A multitude of events can cause chronic insomnia. Long-term stressful situations such as a traumatic experience, difficult home life, or a stressful work environment may cause chronic insomnia. Researchers cannot predict if or when an individual develops chronic insomnia, which is often more challenging to resolve than acute insomnia. However, both types can cause mental health complications that can further irritate and exacerbate insomnia, creating a cycle that can be difficult to break.

Acute insomnia and depression

One cause of acute insomnia may be a stressful work environment. Those struggling with long working hours, like medical residents (as studied in one research group), may experience acute insomnia. In one study, medical residents were asked whether they were experiencing any insomnia symptoms. 85.9% of residents affirmed that they were experiencing acute insomnia caused by long working hours and stressful job situations. 

Many of those who were experiencing acute insomnia were also experiencing mild or moderate depressive symptoms. In addition, 67% of those who slept less than six hours the previous night were experiencing depressive symptoms. Of those experiencing depressive symptoms, 45% labeled their symptoms "mild," and 21% labeled them "moderate to severe."

In contrast, 60% of residents who slept over six hours the previous night reported no depressive symptoms. The study was explicitly geared towards studying acute insomnia, so every intern had only dealt with sleep deprivation for one month or less. Specifically, many of these interns had varying work schedules, so an individual may have been able to sleep over six hours one night and under six hours another night. Since those who were sleep-deprived (had slept less than six hours the previous night) had not been deprived of sleep for an extended period, this study concluded that short-term experiences with sleep deprivation could have lasting consequences.

There are melatonin treatments that may help with symptoms of acute insomnia. Specifically, over-the-counter melatonin supplements are often readily available. Before considering, starting, changing, or stopping any medical treatment, supplement, or medication, speak to a doctor. 

Chronic sleep deprivation or insomnia, as it is experienced over a more extended period, was also found to impact an individual's experience with depression or depressive symptoms. In a systematic review conducted on another group of medical residents, researchers looked at chronic sleep deprivation to determine the link between long-term sleep deprivation and depressive symptoms. At the beginning of the study, only 9% of interns reported chronic insomnia. In the end, 43% of interns reported chronic insomnia after one year of internship. Likewise, the number of interns reporting depressive symptoms grew from 4.3% to 29.8%. This facts suggests that over half of interns that experienced new chronic insomnia also experienced new depressive symptoms. 

This study suggests that chronic insomnia and sleep deprivation also lead to depressive symptoms that are mild or moderate. The studies on insomnia in medical students also showed a higher burnout rate when participants experienced chronic sleep deprivation, which suggests that those who experienced insufficient sleep were more likely to experience stress, anxiety, and a lack of interest in their work. These are also symptoms of depression that can negatively affect an individual's mental state.

Further links between melatonin and depression 

The symptoms of low serum melatonin, a circadian rhythm marker, and depression often go hand in hand. Symptoms of low melatonin levels mirror many symptoms of depression, including the mood changes associated with both. A sleepless night produces mood shifts that can become difficult to remedy if insomnia lasts beyond a few days. The mood changes caused by different types of insomnia may help explain why individuals experiencing sleep disorders could also develop depressive symptoms like anxiety, frustration, hopelessness, exhaustion, and issues with concentration.

These mood changes could lead to a lower quality of life for an individual and can cause decreased school or work performance, an increased risk of self-harm, and in severe cases, suicidal ideation. Physical effects appear from chronic or acute insomnia, such as inflammation, gastrointestinal problems, and other chronic conditions. These physical problems can add to an individual's poor mental state and increase their risk for many mental health conditions. 

If you are experiencing suicidal thoughts or urges, call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255) or text 988 to talk to someone over SMS. They are available 24/7 to offer support. 

Low melatonin levels and sleep disorders have also been proven to lead to relapses in depressive episodes. Those who have had a depressive disorder may be impacted by the mood changes that come with insomnia and slip back into a depressive episode. Studies have found that those who have experienced depression in the past and develop insomnia are two to four times more likely to experience another depressive episode in the future.

Psychologists agree that monitoring an individual's sleep can help predict future depressive episodes, as experiencing insomnia for more than two weeks could indicate a future major depressive episode. Researchers have found that some individuals with chronic or acute insomnia can develop new major depressive disorder (MDD), formerly exogenous or endogenous depression, or another depressive disorder that they have not experienced in the past.

In one study, 16% of individuals who labeled themselves as depressed had experienced sleep disorders or insomnia at least two weeks or more before their depressive episode began. This research confirms what other literature has suggested: that those with insomnia may have an increased risk of developing depression and anxiety. 68% of those interviewed reported that they had developed insomnia symptoms at the onset of or immediately after they developed depression. 

Melatonin and depression

While experts have not determined whether low melatonin is the leading cause of depression, many studies suggest an overlap. Insomnia may lead to many of the same symptoms that those with depression experience, like anxiety, moodiness, increased stress, lower quality of life, or difficulty with performance. In turn, depression can exacerbate sleep deprivation and increase the factors that lead to an individual's insomnia in the first place. Although the impact of melatonin on depressive symptoms is unclear, doctors, scientists, and psychiatrists may recommend lifestyle changes, therapy, or medication to break this cycle.

The is also a link between melatonin production and seasonal weather changes in some people. With individuals receiving less sunlight in the winter months, this has an impact on melatonin production, which could increase depression symptoms. This seasonal depression is called seasonal affective disorder (SAD) and is a mild form of depression. 

Another sleep disorder that may have negative effects on an individual’s energy levels is called delayed sleep phase syndrome (DSPS). DSPS is a sleep disorder in which individuals have trouble falling asleep for at least two hours beyond what is considered acceptable by society, however, once they fall asleep, they are able to stay asleep. This is different from insomnia where a person may struggle to sleep throughout the night.

Counseling options 

For individuals experiencing insomnia, medication may be an option, in a randomized double-blind placebo-controlled trial, insomnia improved when treated with medication.  Fatigue is a prominent symptom of depression and insomnia, which could prevent some people from getting the help they seek. If you're too tired to get out of bed, it can be challenging to make it to a therapy appointment. Online counseling could provide a solution to this problem and help treat depression or other mental disorders. With this type of therapy, you can get support from a mental health professional from the comfort of your home or anywhere you have an internet connection. Online therapy can also be scheduled any time of day or night, which can be beneficial if your sleep schedule has been disrupted.

In addition, this type of therapy may improve depression symptoms or symptoms of other mood disorders as much as in-person therapy. A recent study cited the benefits of internet-based cognitive behavioral therapy for individuals experiencing depression. Online CBT was associated with positive outcomes for depression, anxiety, and chronic stress. 

If you are experiencing insomnia or depression, consider getting professional help. These are both issues that can significantly impact your quality of life.  A licensed counselor, such as one from a platform like BetterHelp, can help you develop an individualized treatment plan.