Narcolepsy is a long-term neurological disorder that involves a decreased ability to regulate sleep–wake cycles. Symptoms often include periods of excessive daytime sleepiness and brief involuntary sleep episodes. About 70% of those affected also experience episodes of sudden loss of muscle strength, known as cataplexy. Narcolepsy paired with cataplexy is evidenced to be an autoimmune disorder. These experiences of cataplexy can be brought on by strong emotions. Less commonly, there may be vivid hallucinations or an inability to move (sleep paralysis) while falling asleep or waking up. People with narcolepsy tend to sleep about the same number of hours per day as people without, but the quality of sleep tends to be lessened.Narcolepsy is a clinical syndrome of hypothalamic disorder, however, the exact cause of narcolepsy is unknown, with potentially several causes. In up to 10% of cases, there is a family history of the disorder. Often, those affected have low levels of the neuropeptide orexin, which may be due to an autoimmune disorder triggered in genetically susceptible individuals by infection with H1N1 influenza. In rare cases, narcolepsy can be caused by traumatic brain injury, tumors, or other diseases affecting the parts of the brain that regulate wakefulness or REM sleep. Diagnosis is typically based on the symptoms and sleep studies, after ruling out other potential causes. Excessive daytime sleepiness can also be caused by other sleep disorders such as sleep apnea, major depressive disorder, anemia, heart failure, drinking alcohol and not getting enough sleep.
Dissociative disorders (DD) are conditions that involve disruptions or breakdowns of memory, awareness, identity, or perception. People with dissociative disorders use dissociation as a defense mechanism, pathologically and involuntarily. The individual experiences these dissociations to protect themselves. Some dissociative disorders are triggered by psychological trauma, but depersonalization-derealization disorder may be preceded only by stress, psychoactive substances, or no identifiable trigger at all.The dissociative disorders listed in the American Psychiatric Associations DSM-5 are as follows:
Dissociative identity disorder (formerly multiple personality disorder): the alternation of two or more distinct personality states with impaired recall among personality states. In extreme cases, the host personality is unaware of the other, alternating personalities; however, the alternate personalities can be aware of all the existing personalities. Dissociative amnesia (formerly psychogenic amnesia): the temporary loss of recall memory, specifically episodic memory, due to a traumatic or stressful event. It is considered the most common dissociative disorder amongst those documented. This disorder can occur abruptly or gradually and may last minutes to years depending on the severity of the trauma and the patient. Dissociative fugue was previously a separate category but is now treated as a specifier for dissociative amnesia. Depersonalization-derealization disorder: periods of detachment from self or surrounding which may be experienced as "unreal" (lacking in control of or "outside" self) while retaining awareness that this is only a feeling and not a reality. The old category of dissociative disorder not otherwise specified is now split into two: other specified dissociative disorder, and unspecified dissociative disorder.