depends on the type of group. theres two different kinds of group therapy....

peer support - this is when its mostly folks who have the same problem or are on the same treatment program get together to talk like friends with others like their self. most times they are where you can do all kinds of discussions about your problems and the treatment program, most peer support groups I have found for anything end up mostly being a B....... and moan fest unless you have a leader of the group who will keep the complaining and downward negative talk spiral to a minimum.

Therapeutic peer or professional led groups have more structure, they have a definite topic each meeting, a definite facilitator who keeps the meeting on track and on topic of the meeting. prevents the downward spiral of the meeting being monopolized or negative downward spiral of being a B and Moan fest. actual practice work gets done where the facillitating person leads the group through a series of skills. they do that through the use of discussions, and actual therapeutic work of practicing the skills that are being taught either through individual therapy sessions or as a class.

in other words

peer support groups whether led by a treatment provider or someone in the group is like recess or coffee hour of people with the same problems or treatment program getting together to talk about their problems and the program.

therapeutic groups whether led by a treatment provider or someone in the group are like going to school and taking a class to study, its structured in a way that allows for learning the educational material and practicing the skills being taught.

there are groups that are a combination of both types of groups but it gets very complicated, and most sink within the first year or two, when trying to mix the flexibility of very little structure with a structured group style.

I have seen many support groups go under because they tried to add educational, and structure and I have seen therapeutic style groups go under with their efforts to add a flexible support structure to their groups.

my suggestion is talk with the group facilitator to get more information about the group, what they do and so on, then decide if thats what you want to do, make your decision after being fully informed about the group. talk with your therapist that is teaching you the DBT skills to be sure the group meets the same standards and such that she /he is teaching you. after you are fully informed on all angles you will be able to make the best decision for you.