Depression presents differently between individuals. Many people describe persistent emptiness or numbness rather than sadness — an inability to feel engaged or interested in anything, even things that previously mattered. Others experience it as a pervasive heaviness, cognitive slowing, or an exhaustion that sleep does not resolve. Some experience primarily physical symptoms: unexplained pain, appetite changes, or disrupted sleep. What unifies these presentations is their persistence, their impact on daily functioning, and their resistance to ordinary efforts to improve mood.