Group members can learn from each other:
"Peer pressure", or power from peers, can be very effective in terms of doing homework, being honest, taking medications.
Effective re: time and energy
Closed groups have people enter together and go through sessions together.
Open groups see people joining as they determine, sort of a drop-in.
It will be important to have some information here.
It can be very nice to not always be alone 1:1 with the doctor, and to learn about common experiences of others.
"Therapeutic community"