Cobb Scott

There have been a couple of meta-analyses done in adult samples, but this is the first one to be done specifically in adolescent and young adult samples, we looked at everything from learning and memory to different aspects of executive functioning such as abstraction ability.

We looked at everything from learning and memory to different aspects of executive functioning such as abstraction ability, and we basically showed that the largest effects -- which was around a third of a standard deviation -- was in the learning of new information and some aspects of executive functioning, memory and speed of processing.

It surprised, I think, all of us doing this analysis that the effects were not bigger than we found, but I would say that the clinical significance of a quarter of a standard deviation is somewhat questionable.

The other thing that's important to highlight is that we're only looking at cognitive functioning. We're not looking at risks for other adverse outcomes with cannabis use, like risk for psychosis, risks for cannabis use problems or other medical issues like lung functioning outcomes.

As attitudes change about cannabis use and cannabis use becomes a little bit more accepted in terms of policy and government regulation and medical cannabis use increases, I think we need to have a real understanding of the potential risks and benefits of cannabis use.