Insomnia has long been recognized as a symptom of depression and anxiety disorders, but we’re learning that the relationship is a lot more complex. While negative thoughts, stress, worry, or irrational fears can keep you up at night and make it hard to fall asleep, good sleep is also essential for your mental health. This means that it isn’t a one-way street and insomnia or poor quality sleep can also contribute to or exacerbate anxiety and depressive disorders. In many ways the link between insomnia, anxiety, and depression is like the classic case of the ‘chicken or the egg’, where it’s hard to really pinpoint either as being the primary cause or the outcome. Understanding their relationship, however, can help in the development of effective prevention and treatment strategies.
How Insomnia Increases the Risk of Anxiety & Depression
Just one night of poor sleep can take a toll on your mood, leaving you feeling fatigued and down the following day. The effects are even worse when you don’t get adequate sleep on a regular basis, so it should come as no surprise that insomnia significantly increases the risk of depression. Studies suggest that individuals who suffer from insomnia may be up to ten times more likely to eventually suffer from depression, as compared to people who sleep well. Even in cases where insomnia doesn’t itself give rise to anxiety or depressive disorders, it can have a cascading effect, delaying recovery from mental illness. For example, research shows that patients are less responsive to treatments for anxiety and depression when they continue to suffer from insomnia.
Although we don’t fully understand how insomnia makes us more vulnerable to depression, we’re gaining new insights from research. It appears that insomnia and sleep deprivation can adversely affect our ability to process and deal with negative emotions. A study that appeared in the journal Biological Psychology shows that individuals suffering from sleep deprivation have a stronger emotional response to negative images, as opposed to those with positive or neutral emotional content. In those with healthy sleep patterns, no such difference in response was observed. Other research also supports these findings, with brain scans revealing higher activity in emotion processing areas of the brain with negative stimuli. What this means is that when you are sleep deprived, you will find it harder to control your emotions, especially when dealing with unpleasant tasks and situations.
Poor quality sleep also has an impact on mood and energy levels, making it hard to stay motivated, focused, and to perform at optimal levels during the day. This reduction in quality of life can make you feel even worse about yourself, increasing the risk of depression and anxiety or worsening the conditions if they are already present.
How Anxiety & Depression Increase the Risk of Insomnia
Insomnia is regarded as one of the key problems that can develop as a result of mental illness, affecting up to 80% of people with depression and around 70% of those with generalized anxiety disorder. While this doesn’t necessarily mean that all cases of prevalence indicate insomnia to be an outcome, patients who suffer from anxiety disorders and depression commonly report difficulty falling and staying asleep. Patients typically suffer from higher than normal levels of psychological distress, making it harder to relax and this reduces one’s ability to fall asleep. It is not uncommon for anxiety to give rise to insomnia, as anxiety disorders involve a heightened state of arousal. Depression on the other hand may not always cause insomnia, but even if an individual gets enough sleep, this is often of a poor quality.
Studies have found that individuals suffering from generalized anxiety disorders tend to have increased sleep latency, which refers to the time it takes for one to fall into the state of sleep. They also have more wakefulness after the onset of sleep, with the combined effect of a reduction in the total amount of sleep time. Early morning awakenings are also a lot more common and may be observed as a symptom in individuals who suffer from either anxiety or depressive disorders.
When it comes to the link between insomnia and anxiety or depression, the relationship is best described as bidirectional, as it’s usually hard to establish which problem appeared first. What’s clear is that having one problem can worsen or trigger the onset of the other and vice versa, making it important to address both problems simultaneously.