Explain why distinguishing a depressive illness from demoralization matters clinically, given that both involve persistent low mood.

Although both presentations involve persistent low mood, they point toward different underlying processes and different management approaches: demoralization is fundamentally a response to an ongoing, specific struggle, and tends to improve once that struggle resolves or the person's sense of agency in relation to it is restored, whereas a depressive illness is a more pervasive, sustained disturbance affecting mood and a wide cluster of associated features across the whole of a person's life, often requiring more specific treatment regardless of whether the precipitating circumstances change. Treating a depressive illness as though it were simply demoralization risks under-treating a serious, potentially severe condition, while treating straightforward demoralization as a depressive illness risks over-medicalising an understandable, situationally-tied response, making the distinction genuinely consequential for how a patient is best helped.