Which of the following is a characteristic symptom of Major Depressive Disorder?

Loss of appetite is a characteristic symptom of Major Depressive Disorder (MDD). In individuals experiencing MDD, changes in appetite and weight are common, often manifesting as a significant decrease in appetite, leading to weight loss. This symptom is linked to the overarching feelings of sadness, hopelessness, and a general lack of interest in activities that were once enjoyable, including eating.

The other symptoms listed—euphoria, excessive energy, and paranoia—are not typical of Major Depressive Disorder. Euphoria and excessive energy are more associated with manic episodes found in Bipolar Disorder. Paranoia may occur in various mental health disorders but is not a defining characteristic of MDD. Understanding the core symptoms of MDD helps in identifying and providing support for those affected by this condition.