The relationship between sleep and mood is a fraught one. We know that good sleep is associated with good emotions. Whether the inverse it true—poor sleep is associated with poor emotions—is harder to determine.
Insomnia is the “subjective experience of difficulty initiating sleep, maintaining sleep, and/or early morning awakening, occurring for at least three nights a week for a duration of at least three months. Further criteria is clinically significant distress or impairment in important areas (e.g., social, occupational, educational) of functioning,” says the criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
Considering that anywhere from 6 to 20.0 percent of the population experiences insomnia, understanding this relationship could help us tackle the issue of poor sleep and bad moods.
So, Norwegian researchers set out to investigate who suffers from insomnia as well as possible depression and possible anxiety occurring in people who experience insomnia.
Insomnia Risk Factors
What they reported in the Frontiers of Psychology is that your risk of experiencing insomnia is higher if:
You are a woman
You have a low education level
You are older (65 or older)
You are separated, divorced, or widowed
You consume alcohol or hypnotics
And while this study didn’t find that insomnia determined mood, according to lead research Ingrid Bjorøy. It did show that anxiety and depression could possibly happen when people experienced certain types of insomnia.
Types of Insomnia
The different subtypes of insomnia are:
Sleep-onset insomnia—when it takes more than 30 minutes to get to sleep
Sleep-maintenance insomnia—when you stay awake for more than 30 minutes after waking in the middle of the night before you fall back asleep
Early morning awakening—when you wake up more than 30 minutes earlier than you wish and are not able to fall back asleep
A combination of two of these
A combination of all three
The Link Between Insomnia And Mood
In fact, this study found that more than 60 percent of the 113,887 participants surveyed experienced either sleep-onset insomnia or a combination of all three. What’s more: possible anxiety, depression and hypnotic use was more prevalent when a combination of all three were experienced.
When it came to mood disorders, strong predictors for anxiety included sleep-onset insomnia combined with the other types of insomnia. As for depression, all subtypes except sleep-maintenance insomnia were positively associated with this mood.
These findings don’t necessarily mean that insomnia causes anxiety, depression and hypnotic use. In fact, all of these things could actually cause sleeplessness. “The relationship between anxiety, depression, and insomnia is bidirectional,” writes Bjorøy and her colleagues.
This research is one of many that adds to the question about which comes first, mood disorders or disordered sleep.
Other insomnia-and-mood research have found that dysfunctions in the sleep-wake cycle reinforce emotional disturbances. “Considering the interaction between sleep and emotional valence, poor sleep quality seems to correlate with high negative and low positive emotions, both in clinical and subclinical samples,” write German researchers in their 2010 scientific review on the subject published in Sleep Medicine Reviews.
Insomnia And Depression
More recently, research out of John Hopkins University Bloomberg School of Public Health suggests that insomnia may have a more predictive role when it comes to depression. Researchers analyzed data from nearly 600 primary care patients who were over the age 60 and experienced symptoms of depression. They found that those who experienced worsening insomnia symptoms over a year were almost 30 times more likely to be diagnosed with depression at the end of that year, compared to patients whose sleep had improved during that time. Additionally, they were more likely to report suicidal ideation at the end of the year. Those with persistent insomnia symptoms experienced persistent depression—it didn’t get better nor did it worsen.
Ultimately, more research needs to be done to figure out the relationship between sleep quality and mood. It seems that with each new study, we learn a bit more. Clearly, getting a good night’s rest is one of the best things we can do to improve our mood. Read more about how a good night’s sleep can improve your mental health.