Depression can be treated clinically by visiting either a psychiatric or psychological department. The main clinical manifestation is a persistent low mood, characterized by an inability to feel joy, gloominess, and typically significant mood variations. Cognitive processes tend to slow down, resulting in sluggish thinking, slow reactions, reduced volitional activities, a passive and listless approach to life, and a lack of hope for the future. Additionally, cognitive impairments such as decreased attention, diminished abstract thinking, learning, and judgment abilities may occur. Some patients may also exhibit physical symptoms, including sleep disturbances, decreased appetite, weight loss, physical pain, and anxiety-related disorders.