But how much of that is down to how freely available booze and cigarettes are, and how much are they socially acceptable?
Modern cannabis has been shown to be 3-4x stronger than from 1995. Earlier samples were measured in a different way which altered the structure of THC and therefore it's measurement.
Having worked in psychiatry, I did find there were increased rates of admission for paranoid schizophrenia whenever there was a new shipment (police reports). These were always men in their 20s to early 30s. The admissions were associated with violent episodes stemming from the paranoia.
