Impact of Sleep on Mental Health: The Dark and Bright Sides

Many people know how sleep loss slows physical reflexes and impacts cognitive abilities. Recall how after a sleepless night, you may take longer to put on the brakes at a spotlight or understand your coworker's speech. But did you know that sleep deprivation ruins your mood and affects your mental health more than your motor and cognitive skills? Just like mental health issues make it challenging to have a good night's sleep, poor sleep can also worsen your mental well-being. But there is always a light at the end of the tunnel; thus, better sleep can improve your mental health and keep psychological issues at bay.

The Impact of Sleep on Mental Health: The Dark Side

When you look at signs of mental health disorders, sleep problems almost always form part of the diagnosis. It could be something as mild as a lack of sleep to as chronic as a sleep disorder. Many people think mental health issues primarily cause impaired sleep patterns. While that narrative isn't false, it doesn't fully represent the sleep impacts on mental health. In the past, healthcare providers and researchers considered that sleep troubles were just a hallmark and consequence of psychiatric disorders. They have evidence that sleep deprivation is the culprit, with circadian misalignment as the accomplice. But what exactly includes sleep deprivation? It can be categorized into two phases.

Acute Sleep Debt

This refers to the amount of missed sleep in the last 14 days relative to your sleep need, which is genetically determined per your body's need.

Chronic Sleep Deprivation

Chronic sleep deprivation is when you experience high sleep debt over many months or years. Did you know our sleep need is as genetically unique as our height and eye color? Instead of the generalized recommendation of 8 hours of sleep, it's more likely your sleep need should be between 7 to 9 hours. Whereas some even need more than that to function at their best. Lack of sleep extends beyond the grouchiness and negativity you feel while waking up. In the below image, we show how sleep deprivation impacts one’s psychological health on the hormonal, physiological, and biochemical levels.

The Prefrontal Cortex and the Amygdala

The PFC (prefrontal cortex) is a part of the brain found in the cerebrum that regulates cognitive functions. It's like creating an Excel spreadsheet to track sales records or thinking of how to explain complicated algebra equations to a student. Meanwhile, the amygdala controls your emotions and memories and triggers your fight-or-flight response when you feel a threat. So what's the connection between the PFC and the amygdala relative to sleep? You can understand it assuming PFC is the "parent" and the amygdala is the "child" needing supervision. When you adequately sleep, the PFC has no difficulty reining in the amygdala to deter it from going out of control emotionally. But when you're sleep-deprived, the PFC removes its inhibitory control over the amygdala.

Biochemical Alterations

Sleep deprivation disrupts the standardized balance of brain chemicals and hormones. According to research, sleep deprivation raises the level of serotonin 2A receptors in just 6-8, which are associated with cognitive impairment, hallucinations, and schizophrenia. Furthermore, sleep deprivation also affects oxytocin, also known as the love hormone. Oxytocin helps regulate anxiety by reducing cortisol production and suppressing the brain's response to negative stimuli. It also increases your ability to recognize emotions. However, there's a dark side to oxytocin. Scientists say that while oxytocin decreases stress levels and increases good vibes, it can elevate fear and anxiety. Adults with autism,  bipolar disorder, schizophrenia, and generalized social anxiety have higher oxytocin levels than usual. An oxytocin surge also links with signs of depression in children with obsessive-compulsive disorder (OCD) and comorbid anxiety disorder.

It’s a Downward Spiral

Sleep deprivation continuously downgrades your mental health, from everyday stress to suicidal thoughts.


Because sleep exerts an inhibitory effect on cortisol production, lack of sleep means the stress hormone runs rampant in the human body. The regular influx of cortisol in your system disturbs your mental wellness and activates stress symptoms.


Sleep and anxiety are linked with each other. For some, sleep disruption is a common sign of anxiety disorders. However, at the same time, sleep deprivation can trigger anxiety. Furthermore, a single night of poor sleep increases daytime anxiety levels with clinically diagnosed anxiety disorders in some individuals.


Different studies reveal that depression and sleep difficulties often go hand in hand. For beginners, chronic insomnia increases the risk of depression in affected people. Sleep-related breathing disorders, i.e., obstructive sleep apnea, are also associated with depression. Moreover, long-term sleep deprivation and a disrupted circadian rhythm also trigger daytime sleepiness and mood disorders.

Anger Issues

Some people become grumpier after a disturbing night of sleep, making us less adept at managing minor stressors in routine. A study published in the journal Emotion emulates this in a significant way. During low-stress events, people with sleep deprivation showed more stress, anxiety, and anger than their well-rested counterparts. The study stated that "sleep deprivation reduces the psychological threshold for the perception of stress from cognitive needs." This negatively impacts your interpersonal relationships and, by extension, your quality of life. Numerous studies have shown that lack of sleep contributes to romantic strife and makes it more difficult for partners to resolve disagreements peacefully.

Suicidal Thoughts

Suicidal thoughts are a serious and concerning issue that can arise due to poor mental health. Unfortunately, the impact of sleep on mental health can contribute to the development of suicidal thoughts. Chronic sleep deprivation can lead to increased anxiety, depression, and irritability, making it challenging to manage daily stressors. Sleep disturbances are also common symptoms of mental health disorders, such as bipolar disorder and post-traumatic stress disorder (PTSD). Studies have shown that individuals with poor sleep quality are more likely to experience suicidal thoughts and behaviors. It increases impulsivity, reduces emotional regulation, and impairs decision-making abilities, all of which can contribute to suicidal behavior.

It's Not All About Your Mental Health on the Line

Remember that poor mental health is contagious. Your bad mood can impact your friends, family, and coworkers; this phenomenon is known as emotional contagion. What's the reason behind it? In any social interaction, we copy others' facial expressions, tone of voice, and actions, whether intentionally or not. Perhaps you may think that emotional contagion is only catching in person. But, interacting on social platforms, i.e., Facebook and Instagram, can also cause emotional contagion. Sleep is crucial to human physiology and behavior and significantly impacts mental health. While sleep deprivation is associated with negative mental health outcomes, there is also evidence to suggest that getting enough sleep can have a positive impact on mental health. One way in which sleep can positively impact mental health is by improving cognitive function. The brain consolidates memories, processes information while sleeping, and improves cognitive performance.

Sleep Improves Your Mental Health

Research suggests that improving your sleep is more beneficial for psychological health than the other way around. The benefits of better sleep can be felt after just two recovery nights. You don’t need to use sleep medications to improve your sleep. Sleep supplements and aids are not recommended for promoting naturalistic, healthy sleep, which is crucial for optimal mental health. Instead, many sleep experts recommend cognitive behavioral therapy for insomnia (CBT-I) for those with difficulty falling asleep. CBT-I combines psychological and behavioral interventions to provide a two-pronged approach to mental health and sleep issues. In addition to therapeutic interventions like CBT-I, maintaining good sleep hygiene is essential. Sleep hygiene refers to behaviors that affect your sleep; many sleep practices occur during the day. Despite this, they are still considered part of sleep hygiene due to their impact on sleep.

Some key examples include:

A consistent sleep routine: Establishing a consistent sleep schedule is crucial to maintaining a steady internal clock and meeting your sleep needs. It's essential to wake up and go to bed around the same time every day.

Avoidance of inappropriate stimulants: Nicotine, caffeine, and alcohol are notorious for their stimulating effects that can disrupt your sleep. To avoid this, you must reduce the time consuming these substances based on your unique chronobiology.

Take afternoon naps: Napping during the afternoon dip can effectively repay your sleep debt without disturbing your circadian rhythm. However, it is crucial to do it correctly.

Create a conducive sleep environment: The best sleep environment is calm, dark, and quiet, which helps you fall asleep effortlessly and remain relaxed until morning.

Follow a wind-down routine: You can disengage from the day's stress, worry, and anxiety by deliberately relaxing your mind and body. Get enough sleep by meeting your target bedtime by prioritizing your evening wind-down.
Final Words In conclusion, the relationship between sleep and mental health is complex and multifaceted. While poor sleep can negatively impact mental health, a healthy sleep routine can positively affect mood, cognitive function, and overall well-being. By understanding the importance of sleep and prioritizing good sleep hygiene, we can take control of our mental health and enjoy the bright side of a good night's sleep. Remember, minor changes to your sleep habits can significantly affect your mental and emotional wellness.