A single dose of an experimental psychedelic nasal spray eased depression in adults who had not been helped by other treatments, Medscape and Ynet report. The trial of 193 people was published on October 26 in the medical journal JAMA.

The spray, called BPL-003, contains a lab-made form of mebufotenin, also known as 5-MeO-DMT, Medscape reports. The drug is found in some plants and in the venom of the Colorado River toad. Its effects are short and often fade within an hour. Most patients were ready to go home within two hours, though the rules made them stay at least four, the outlets report.

Patients got a dose of 8 or 12 milligrams, or a tiny dose of 0.3 milligrams that served as the comparison. All of them had support from a therapist before, during and after the dose. Symptoms got better as early as the next day, and the gap with the comparison group lasted through eight weeks, Ynet reports.

After about four weeks, roughly a third of patients on the real doses saw their symptoms drop by at least half, compared with 12% in the comparison group, the outlets report. Most side effects were mild, such as headache and nausea. One patient had two severe panic attacks.

The gains were modest. In an editorial in the journal, Dr. Chittaranjan Andrade wrote that "the average patient became only about 30% better," Medscape reports. The study was paid for by Beckley Psytech, now part of Eli Lilly, Medscape says. Company staff helped design and run the trial, Ynet reports. The 8-milligram dose was picked for larger trials.

What we know: One dose helped many patients for at least eight weeks in a trial paid for by the drug's maker.
What we don't: Whether the benefit lasts longer, and how the spray compares with other fast-acting treatments such as ketamine.