Evidence

Years ago another doctor in town and the local policeman were vehemently anti marijuana. The personal experience of a pot smoking son in his late teens developing schizophrenia fueled one of these gentleman. The other's reasons I never got to hear. Their convictions didn't fit with my experience. I was on the side of the hippies. When the drug squad assembled outside the police station in the early hours readying for a raid, I'd hear them and make a couple of calls.

Anyway I started collecting research papers. I filled the lower draw in my desk. I sorted the papers into for and against. The end result was about 50% for and 50% against. Seldom does a literature search generate certainty.

My opinion - the brain goes on developing into our mid or late 20s. The brain has a lot of fatty stuff in it. Marijuana is fat soluble and hangs around for weeks. No argument so far. It flattens motivation. No argument here either. It may interfere with brain development. Maybe maybe not! If you are below 25 minimal use is advised. It could ruin a potentially bright future in some susceptible young folk and no one knows for sure - so why risk it. Making it illegal and criminalising users achieves nothing of value for anyone except those selling it.

All can select from the evidence research to support their point of view.