Which of the following is a behavioral symptom of major depressive disorder?

Suicidal ideation is recognized as a significant behavioral symptom of major depressive disorder. This term refers to thoughts or considerations of ending one's life often stemming from severe feelings of hopelessness, helplessness, or worthlessness that are prevalent in individuals suffering from this condition.

Those experiencing major depressive disorder may find themselves overwhelmed by their symptoms, leading them to contemplate self-harm as a way to escape their emotional pain. This symptom is crucial to address both in diagnosis and treatment because it can indicate a heightened risk of suicide, requiring immediate intervention and support from mental health professionals.

The other options, such as increased sociability, persistent happiness, and enhanced concentration, contradict the typical behavioral patterns found in individuals with major depressive disorder. Instead, those with the disorder often experience social withdrawal, persistent feelings of sadness or emptiness, and difficulty concentrating or making decisions, rather than enhanced capabilities in these areas.