From The PTSD Trap: Our Overdiagnosis of PTSD In Vets Is Enough to Make You Sick:
The most recent Diagnostic and Statistical Manual (DSM-IV) defines PTSD as the presence of three symptom clusters — reexperiencing via nightmares or flashbacks; numbing or withdrawal; and hyperarousal, evident in irritability, insomnia, aggression, or poor concentration — that arise in response to a life-threatening event.
Both halves of this definition are suspect. To start with, the link to a traumatic event, which makes PTSD almost unique among complex psychiatric diagnoses in being defined by an external cause, also makes it uniquely problematic, for the tie is really to the memory of an event. When PTSD was first added to the DSM-III in 1980, traumatic memories were considered reasonably faithful recordings of actual events. But as research since then has repeatedly shown, memory is spectacularly unreliable and extraordinarily malleable. We routinely add or subtract people, details, settings, and actions to our memories. We conflate, invent, and edit.
I am skeptical about the existence of the diagnosis as a disease entity, because it sounds like a normal, or at least unremarkable, reaction to me. Intense reactions to intense things in life is not pathological. It's how life shapes us, twists us, and eventually wears us down and ultimately kills us. Who said "Reality is for people who can't handle drugs"?
Show me one adult who does not harbor some deep pain which affects his life in mostly negative ways. I'd like to meet them. There's a CS Lewis quote which I cannot remember but which goes something like "Be kind, because everyone you meet is enduring some deep struggle and pain." It's not called "a vale of tears" for nothing. People - and kids - are commonly permanently wounded by divorce, for example. Some joy and delight in life too, thank God.
However, I do understand that nowadays people want their struggle called a disease so they can get insurance and/or disability checks.