if marijuana actually increases cortisol, it's certainly not going to act as a stress reliever or anti-anxiety agent.
you would think that any serious scientific argument for "marijuana as a medicine" would try to link marijuana use to decreased cortisol levels, rather than rely on subjective opinion surveys, which is what they seem to actually do.
the silence on the topic is telling.
https://www.sciencedirect.com/science/article/pii/S0306453017301130