In the months leading up to Perry's death, Mark Chavez said in a plea deal he conspired to distribute liquid ketamine and ketamine lozenges to Perry through transactions with another doctor.

Ketamine, approved as an anesthetic in 1970, is emerging as a major alternative mental health treatment. But more than 500 clinics have popped up with little regulation, and treatment varies widely.

The Georgia EMDR Network has 150 certified specialists, but its community coordinator Angie Heath estimates hundreds of therapists throughout the state are using EMDR — eye movement desensitization and reprocessing — techniques for people with post-traumatic stress disorder.

An obscure bit of brain tissue appears critical to both out-of-body experiences and our sense of being anchored to a physical self.

In a recent small study, the antidepressant effects of ketamine lasted longer when an intravenous dose was followed with computer games featuring smiling faces or words aimed at boosting self-esteem.

Ketamine, a Schedule III non-narcotic substance, has been available to licensed prescribers since the 1970s. Since then, multiple studies have shown ketamine helps some depression patients who feel as though they’ve tried everything else. 

Researchers were able to mimic the mind-altering effects of the drug ketamine by inducing a particular rhythm in one area of the brain.

Doctors have a new option for suicidal patients. It's a fast-acting nasal spray containing a version of the anesthetic ketamine.