Treating mood disorders with psychoactive drugs

There is a need for new, effective treatments for mental illnesses like depression and anxiety. Researchers are expanding the field's therapeutic toolbox by investigating the antidepressant and anxiolytic properties of drugs such as psilocybin and cannabis. The findings were presented at Neuroscience 2022, the annual meeting of the Society for Neuroscience and the world's largest source of emerging news about brain science and health.

Mood disorders are among the most frequently diagnosed mental illnesses worldwide. Current drug treatments for these disorders, such as serotonin modulators and benzodiazepines, are slow to take effect, and when they do, they often bestow unwanted side effects. Additionally, many people with depression don't respond at all to these medications.

However, treatments derived from the psychedelic compound psilocybin and the psychoactive drug cannabis may be promising for a range of mental health disorders. Neuroscientists are probing how they work in the brain.

Today's new findings show that:

• The altered consciousness effects of psilocybin may not be necessary for it to produce anti-anxiety and anti-depressive effects in mice. (Katherine M. Nautiyal, Dartmouth College)
• In male rats, symptoms of depression and anxiety following chronic stress may be improved by drugging a protein in the brain's endocannabinoid system. (Steven R. Laviolette, University of Western Ontario)
• Chronic cannabis use is associated with improvement in some cognitive functions in people with bipolar disorder. (Alannah Miranda, University of California, San Diego)

"As a field, we are thinking about psilocybin and cannabis in new ways and not only evaluating them for their potential therapeutic benefit but probing how they exert their effects in the brain," says Lisa Monteggia, the Barlow Family Director of the Vanderbilt Brain Institute and professor pharmacology at Vanderbilt University, who studies mechanisms underlying antidepressant efficacy. "The research presented today is contributing to the growing evidence that these compounds may offer new avenues for symptom relief in many mental health conditions."