Does marajuana really help a person who is Bipolar?

My concern is the way the boy acts and my niece doesn’t think anything about it. She has been told that she needs to see a Physciatrist to get on some kind of medicine to control her swings. She said she doesn’t like the it makes her feel and prefers the “natural medicine” of marajuana. while the boy is smelling this, could he be in withdrawals that might be one of the reasons for his actions/