Lately, retired Army specialist Rob Gibson has only two hobbies: video games and researching his own brain. He can dominate a Counter-Strike map and he can explain the hormonal feedback loops of his neuroendocrine system, but that’s about it. He used to love nature — hiking, kayaking, and fishing — but no longer feels safe outdoors. He was a big reader but now struggles to get through even a few pages of his favorite book, Tom Clancy’s Rainbow Six. Two months ago he dropped out of Bellevue University in Nebraska, where he’d been studying cyber security. So now he sits, usually in the dark, alternating between video games and, as he puts it, “obsessively researching this shit.”

Five years have passed since Gibson, 27, completed his final tour in Iraq, where he was a cavalry scout focused on reconnaissance tasks. In the interval between then and this summer he’d been, for the most part, just fine. But while barbecuing with some friends on July 4, he suffered the first of a string of panic attacks that would send his life into a downward spiral. “All of a sudden I had this feeling like I'm not real and the world is not real,” he recalls. “Things just kind of went boom.”

Since then, he’s endured a constant churn of anxiety accompanied by frequent panic attacks, sensitivity to light, night terrors, and the occasional bout of depersonalization (this concept of "not feeling real"). The hardest part, he admits, was not knowing why this was happening.

One month ago, Gibson was diagnosed with post-traumatic stress disorder. To his surprise, the therapist pinpointed a minor car accident in June as the trigger. After the driver fled the scene, Gibson had instinctively entered Army mode, "securing his position" on the side of the road and phoning the cops for backup. It didn’t seem like a big deal at the time, but it was the closest thing to combat he’d experienced since coming back stateside in 2011.

“You never had trauma since then, so your brain just kind of connects the dots and puts you back into Iraq again,” Gibson says his therapist told him. “Your brain decided it's time to deal with this stuff you repressed for all these years.”

There is something about his therapist’s phrasing — the reference to the brain as independent from the self — that resonates with Gibson. While he tends to describe his symptoms in the abstract, he can articulate the architecture of his brain with a detached lucidity. He describes his overactive hypothalamic-pituitary-adrenal axis as if it were a noisy upstairs neighbor, his disrupted neurotransmitters like they’re overworked messengers in an otherwise functional chain of command.

But repairing that architecture is proving difficult. The depression meds make him more depressed; the anxiety pills leave him queasy. Weekly therapy, while helpful, just isn’t enough. At the urging of his Army buddies, he recently applied to some intensive treatment programs but hasn’t heard back from any yet. For now, Gibson has his own method of dulling the symptoms: video games.