What triggered Dan's panic attack?

Dan Harris's panic attack was triggered by a combination of factors related to stress and drug use. After returning from covering combat zones, Dan experienced depression but was not self-aware enough to recognize it. To cope, he began using recreational drugs like cocaine and ecstasy, which provided temporary relief but exacerbated his mental health issues. This buildup of unchecked stress and drug influence culminated in a panic attack while he was live on television. He describes the experience of his lungs seizing up, his heart racing, and being unable to speak, which are typical symptoms of a panic attack 1.