| Behavioral symptoms | Causes in depression | Causes in schizophrenia |
|---|---|---|
| Little or no interest in activities, staring into space for long periods of time | Lack of pleasure in activities (anhedonia), difficulty making decisions | Difficulty initiating behavior (avolition) |
| Short or “empty” replies to questions | Lack of energy | Difficulty organizing thoughts to speak |
| Social isolation | Lack of energy, anhedonia, feeling undeserving of companionship | Feeling overwhelmed by social situations, lack of social skills |