How Sleep Affects Mental Health
Poor sleep has increasingly been recognised as both a symptom and a contributor to mental health disorders. Chronic sleep deprivation and sleep disturbances are associated with higher risks of depression, anxiety, and cognitive impairments. This relationship is bidirectional—poor sleep can worsen mental health, while mental health disorders can disrupt sleep patterns.
*Research shows that inadequate sleep alters emotional regulation, heightens stress responses, and impairs memory consolidation, all of which can exacerbate mental health issues across all age groups and populations.
The Mental Health Impact of Poor Sleep
1. Increased Anxiety and Worry
Chronic sleep deprivation can increase levels of cortisol (the stress hormone) and make it harder to regulate feelings of fear or worry. People with insomnia are more likely to develop anxiety disorders over time.
2. Higher Risk of Depression
There is a strong two-way link between sleep and depression. Poor sleep can trigger or worsen depressive episodes, while depression can make falling or staying asleep more difficult. In fact, insomnia is one of the earliest warning signs of depression.
3. Mood Swings and Irritability
Lack of sleep can reduce activity in the brain’s prefrontal cortex (involved in decision-making and emotion regulation) and increase reactivity in the amygdala (associated with fear and anger). This imbalance can lead to more frequent mood swings, irritability, and poor impulse control.
4. Worsening of Existing Mental Health Conditions
People with mental health conditions like bipolar disorder, PTSD, or schizophrenia often experience sleep disruptions. Unfortunately, poor sleep can also worsen these conditions, making symptoms harder to manage.
How Much Sleep Do You Need?
- Adults: 7–9 hours per night
- Teenagers: 8–10 hours
- Children: 9–13 hours, depending on age
Consistency is key—regular bedtimes and wake times help stabilise your body’s internal clock, which benefits both sleep and mental health. *Research shows that shorter than recommended sleep durations, and sometimes longer than recommended sleep durations, exhibited a higher risk of mental disorders and reduced levels of subjective wellbeing.
Tips to Improve Sleep and Support Mental Health
- Keep a regular sleep schedule, even on weekends
- Limit caffeine and alcohol, especially in the few hours before bed
- Create a calming bedtime routine (e.g., reading, gentle stretching)
- Seek help for ongoing sleep problems such as insomnia or sleep apnoea
When to Seek Help
If you are consistently struggling to sleep and it’s affecting your mood, energy, or concentration, speak with your doctor, or if you believe you have symptoms of sleep apnoea you can call Home Sleep for a level 2 lab quality sleep study conducted in the privacy and comfort of your own home, anywhere in Australia.
Treating sleep issues early can be a powerful step toward improving your overall mental health.
References: (*)
Karine Alexandra Del Rio João, Saul Neves de Jesus, Cláudia Carmo & Patrícia Pinto (2018). The impact of sleep quality on the mental health of a non-clinical population. Sleep Medicine, 46, 69-73
Kahn, M., Sheppes, G. & Sadeh, A. (2013). Sleep and emotions: Bidirectional links and underlying mechanisms. International Journal of Psychophysiology, 89, 218-228
Konjarski, M. Murray, G., Vien Lee, V. & Jackson, M. (2018). Reciprocal relationships between daily sleep and mood: A systematic review of naturalistic prospective studies. Sleep Medicine Reviews, 42, 47-58
Vestergaard, C., Skogen, J., Hysing, M., Harvey, A., Vedaa, O. & Sivertsen, B. (2024). Sleep duration and mental health in young adults. Sleep Medicine, 115, 30-38