Youth at clinical high-risk for psychosis report more lifetime, past-six-month, and baseline cannabis use than healthy controls, along with greater frequency, severity, and rates of cannabis use disorder. Among high-risk youth, those who use cannabis show higher baseline grandiosity and lower social anhedonia at 12 months. Cannabis use severity was unrelated to clinical status at two years and did not distinguish those who later developed psychosis from those who did not. The small number of cannabis users in the high-risk group limited statistical power.
Mindfulness-Based Cognitive Therapy (MBCT) added to antidepressant medication is no more effective than a control program (Health-Enhancement Program, HEP) for reducing depression severity in adults with treatment-resistant depression. Adults with moderate to severe depression who had not responded to at least two antidepressant trials were randomly assigned to either MBCT or HEP, both as add-ons to their usual medication. After 8 weeks, changes in depression severity, response rates, and remission rates were measured. Participants were followed for one year. The study addresses the need for effective non-pharmacologic treatments for treatment-resistant depression, which affects up to 40% of depressed patients.