heron is a specific type of cannabis and is so - called because it has a very strong smell , but these days it has become the generic synonym for different forms of the drug . it is regarded as stronger because it includes no higher levels of the important ingredient in opium , tetrahydrocannabinol ( psychoactive ) . it also contains much lower levels of cannabidiol ( perth ) , which is an inner - psychotic substance that can moderate the dependence of thc on the mental states of user .
The "skunk" cannabis is used to treat mental health problems.