As explained by Ben Johnson, PhD, and the American Psychological Association, "Joining a group of strangers may sound intimidating at first, but group therapy provides benefits that individual therapy may not. Psychologists say, in fact, that group members are almost always surprised by how rewarding the group experience can be.
Groups can act as a support network and a sounding board. Other members of the group often help you come up with specific ideas for improving a difficult situation or life challenge, and hold you accountable along the way.
Regularly talking and listening to others also helps you put your own problems in perspective. Many people experience mental health difficulties, but few speak openly about them to people they don't know well. Oftentimes, you may feel like you are the only one struggling — but you're not. It can be a relief to hear others discuss what they're going through, and realize you're not alone.
Diversity is another important benefit of group therapy. People have different personalities and backgrounds, and they look at situations in different ways. By seeing how other people tackle problems and make positive changes, you can discover a whole range of strategies for facing your own concerns.
While group members are a valuable source of support, formal group therapy sessions offer benefits beyond informal self-help and support groups. Group therapy sessions are led by one or more psychologists with specialized training, who teach group members proven strategies for managing specific problems." (http://www.apa.org/helpcenter/group-therapy.aspx; Retrieved September 2017)