Nervousness or anxiety, sleep difficulties (like insomnia), decreased appetite or weight loss, and depressed mood are symptoms of what condition?

The symptoms described—nervousness or anxiety, sleep difficulties such as insomnia, decreased appetite or weight loss, and depressed mood—are indicative of withdrawal symptoms that may occur when a person stops using certain substances. Cannabis withdrawal can lead to a range of psychological and physical symptoms, including those mentioned.

The understanding of withdrawal symptoms is key in substance use treatment, as they can significantly impact a person's emotional and physical wellbeing. Cannabis withdrawal may not be as severe as withdrawal from other substances, but it can still cause significant distress and impair functioning.

This is why the option detailing cannabis withdrawal is appropriate, given that it directly addresses the specific symptoms associated with the cessation of cannabis use.