super-potent cannabis

"The average psychotic cannabis user is more likely to use skunk.”

"One preliminary study compared cannabis users with just tetrahydrocannabinol [THC] in their hair samples - typical of skunk use - and those with both cannabidiol [CBD] and THC, which showed that they were smoking old-fashioned cannabis. Those with just THC were more likely to show psychotic symptoms. Another preliminary study showed that CBD seemed to have some effect when given as an antipsychotic, and could even block the effects of THC."
- Professor Robin Murray is a consultant psychiatrist at the Institute of Psychiatry and leading researcher into the effects of cannabis on mental health

“I would err on the side of caution. There is still not enough known about skunk but the evidence suggests that it can trigger psychotic symptoms in susceptible individuals."
- Dr Paul Broks, MSc, DPhil, CPsychol, Neuropsychologist

A look at skunk here and here.