The therapeutic efficacy has been impressive, as reflected in a drop in average scores on the Hospital Anxiety and Depression Scale from about 20 to 5.
"Interestingly, several patients had diagnosable severe anxiety disorders that went away completely. We’re finding that anxiety may be even more affected by ketamine than depression," Dr. Irwin said.
The high burden of somatic symptoms present in these patients also lightened significantly, with scores on the Adverse Symptom Checklist falling from about 28 to 5. This doesn’t appear to be a result of the drug’s analgesic effect, because some patients didn’t have significant pain, while in others the somatic symptoms improved while pain scores remained unchanged.
Another 30 or so San Diego Hospice patients have received oral ketamine outside of the pilot study, with similar benefits.
"We’ve gone to nightly dosing. And if you see a decrement in benefit, bump up the dose by 20%," Dr. Irwin advised in response to audience questions.
He called depression near the end of life a major yet widely underappreciated public health problem. The consequences of untreated depression in these patients include longer inpatient hospital stays, worsening medical illness, greater difficulty in treating pain and nausea, and interference with making preparations for death. Untreated depression also impedes interactions with caregivers and, most importantly, with loved ones.
Dr. Irwin recalled one of the first hospice patients for whom he prescribed methylphenidate. After 24 hours on treatment, the man no longer met criteria for major depressive disorder. He lived for another week with newly restored enjoyment of nature and his family. Dr. Irwin learned of his death when he ran into the patient’s daughter in the parking lot.
"She said, ‘I want to thank you for giving me my father back. I will now remember him as the great man he always was, and not the miserable man that he’d become for the last 6 months,’ "
Dr. Irwin said. "So we changed her life for decades.
"If anyone asks you, ‘Why bother treating depression in hospice when you’re only changing the last few days?’ tell them it’s a family experience. It’s not just about the patient."
He reported having no financial conflicts.