Narcolepsy is associated with which of the following?

Narcolepsy is primarily characterized by persistent sleepiness and sudden sleep attacks, which are often uncontrollable and can occur during wakeful periods. This condition is closely tied to a deficiency in hypocretin (also known as orexin), a neuropeptide that plays a critical role in regulating wakefulness and arousal. The lack of this neuropeptide contributes to the core symptoms of narcolepsy, such as excessive daytime sleepiness, sleep paralysis, and episodes of cataplexy, where sudden loss of muscle tone occurs, frequently triggered by strong emotions.

The other choices do not relate to the characteristics of narcolepsy:

Excessive food consumption followed by compensatory behaviors is specific to eating disorders, particularly bulimia nervosa. The inability to control bowel movements aligns with fecal incontinence, which is not a symptom of narcolepsy. Distress regarding gender incongruence pertains to gender dysphoria, a completely different psychological concept that focuses on the mismatch between an individual's experienced or expressed gender and the one assigned at birth.

Thus, the connection between narcolepsy and hypocretin deficiency is fundamental and aligns directly with the pathophysiology of the disorder, making it the correct answer in this context.