So as far as I can tell the only good affect of marijuana is the release of dopamine. However dopamine is not meant to be absorbed in large quantities like weed does. Furthermore there are much healthier ways to release dopamine such as riding a bike or playing sports. Even reading a book releases dopamine. While we are at it here are some more affects I found in my research:
Feelings of panic, anxiety and fear (paranoia)
Hallucinations
Increased heart rate
Trouble concentrating
Decreased ability to perform tasks that require coordination
Decreased interest in completing tasks
source
So what is good about marijuana again?
id like to quote this post and give a shoutout to cannabis for saving me from many breakdowns and terrible heartache-nights
loving love it dude, if it wasnt for weed id be down to emotion killing medication