In "Darkness Visible: A Memoir of Madness," William Styron emphasizes that loss is a central theme in the experience of depression. He suggests that feelings of loss can be a critical factor in both the development and progression of depressive illness. This notion highlights how varied aspects of loss—whether personal, emotional, or existential—can deeply impact mental health.

Styron's exploration sheds light on the intricate relationship between loss and depression, suggesting that recognizing this connection might be crucial for understanding the disease. By considering loss as a potentially foundational aspect of depression, readers gain a deeper insight into the complex nature of mental struggles and the experiences of those who suffer from them.