If you've been diagnosed with depression, you may be having trouble getting to sleep or staying asleep. There's a reason for that. There is a definite link between lack of sleep and depression. In fact, one of the common signs of depression is insomnia or an inability to fall and stay asleep. If considering a survey, more than 40 million Americans suffer from chronic, long-term sleep disorders, and an additional 20 million report sleeping problems occasionally, according to the National Institutes of Health. Sleep patterns, including insomnia, are affected by any number of physical, mental, emotional, and even social issues. When it comes to the link between insomnia and mental health, the relationship may best be described as bidirectional, meaning one can worsen the other and vice versa.