Understanding the connection between insomnia and depression¹

People battling with insomnia have difficulty falling or staying asleep or experience non-restorative sleep. 20 - 35 % of the general population report that they battle with insomnia symptoms. Researchers have shown that insomnia can negatively affect both your physical and mental health (e.g. increase your risk of depression and/or anxiety disorders).¹

Depression is a common mental health condition that ranges from a few depressive symptoms to major depression.¹

Symptoms of depression include²:

• Persistent sad, low, or irritable mood
• Feelings of hopelessness, worthlessness, or guilt
• Loss of interest or pleasure in activities
• Decreased energy and extreme tiredness (fatigue)
• Difficulty concentrating
• Low appetite or overeating
• Thoughts of death or suicide
• Insomnia, waking up too early, or oversleeping

Depression and sleep issues (e.g. insomnia) have a reciprocal relationship. This means that having depression makes a person more likely to experience sleep problems and that poor sleep can lead to the development of depression.²

Over the course of the night, your total sleep is made up of 4 – 6 sleep cycles. Each sleep cycle consists of 4 stages: one for rapid eye movement (REM) sleep and three that form part of non-rapid eye movement (NREM) sleep.⁶

The breakdown of a person’s sleep into various cycles and stages is referred to as sleep architecture.⁶

Deep sleep (stage 3) is critical to restorative sleep. It allows for growth and for your body to recover from the day.⁶

During REM sleep, your brain activity ramps up, close to levels seen when you are awake. This can cause you to experience vivid dreams. REM sleep is also essential for maintaining cognitive functions (e.g. memory, learning and creativity) and for the reprocessing and consolidation of emotional experiences in the limbic system of your brain.^5,6

Arousal (becoming more alert to an extent during a sleep cycle) occurs due to changes in your brain wave activity. It does not necessarily mean that you wake up, but could just mean a shift out of deep sleep to lighter sleep, from which it is easier to be woken up from. Frequent arousals can however lead to unstable or fragmented (repeated interruptions) sleep architecture.^5,7

Excessive arousal and repeated interruptions (fragmentation) to REM sleep, which occurs in both insomnia and depression, can negatively affect how your brain regulates your emotions (reducing its ability to eliminate negative emotions).⁵

If you’re battling with sleep problems like insomnia, and troubled feelings or low mood, speak to your doctor about the treatment options that are available to you. Research has shown that treating insomnia may lessen depression severity, hasten recovery and lower relapse rates^.2,4

Disclaimer
In preparing this article, every effort has been made to provide an objective overview. The content contained in this article contains medical or health sciences information as per cited articles for public information. The content of this article has been initiated and is brought to you by Sanofi South Africa.