Depression is a complex mood disorder that presents a unique and profound pain that can be difficult for individuals to articulate or even understand fully. Those who have not suffered from severe depression may find it hard to grasp its intensity, often mistaking lighter feelings of sadness or "the blues" as a true reflection of depression. The experience of this illness can feel so far removed from everyday emotional struggles that it seems almost beyond description.

Many people struggle with temporary feelings of sadness related to daily life, which can offer a glimpse into the more severe forms of depression. However, these fleeting emotions do not capture the devastating nature of the disorder when it reaches its extreme. In "Darkness Visible," Styron highlights the challenges in expressing and comprehending the depths of despair that accompany severe depression, illustrating the stark divide between casual feelings of melancholy and profound emotional suffering.