Sleepwalking is classified as a parasomnia, an abnormal behavior during sleeping, that disrupts sleep. This abnormal behavior is very similar to any other actions that people do during the night, such as your body moving to get comfortable, snoring, pulling the covers, kicking, and twitching. Another one of the most common causes of sleepwalking is sleep deprivation. When a person is sleep deprived, they will go into a much deeper sleep, causing them to sleepwalk. They can also experience non-REM (rapid eye movement) early in the night which is the most common time for sleepwalkers (Lambert). Depression, a serious mental illness, is also found to be a cause of sleepwalking. A study found that people with depression are three and a half times more likely to sleepwalk than those without depression (Jaslow). Other disorders that have been associated with sleepwalking are obsessive-compulsive disorder and alcohol abuse. There are also medications that can generate this behavior. Antidepressants, SSRIs, have been found to be a cause of sleepwalking. Over-the-counter sleeping pills increase the likelihood of inducing sleepwalking more than prescription sleeping pills do.