One of the biggest dangers for people who have prolonged sleep disruption is the risk of developing depression or substance abuse. The conditions often go hand in hand, and doctors aren't always sure which came first.
More about sleep and depression
Dealing with depression often involves its own treatment regimen, in addition to anything you may be undergoing for your sleep problems. That's why it's important, if you or a loved one begins experiencing signs of depression, to alert your doctor immediately.