Which of the following options is a possible symptom of major depression?

Persistent feelings of sadness are indeed a hallmark symptom of major depression. Individuals experiencing major depression often report feeling a deep sense of hopelessness or a pervasive low mood that lasts for most of the day, nearly every day. This symptom is crucial for diagnosis, as it indicates a significant emotional disturbance that can affect a person's daily functioning, relationships, and overall quality of life.

In contrast, while increased appetite can occur in some individuals with depression, it’s not a defining characteristic since some may experience a decrease in appetite instead. Eagerness for social events and enthusiasm for self-care are generally associated with positive emotional states and are not indicative of major depression. Thus, the persistent feelings of sadness are universally acknowledged as a core symptom of the condition.