When an individual first seeks professional help to deal with an emotional or psychological issue, counseling sessions are usually one-on-one with a trained psychotherapist or psychologist. As these sessions progress and the client becomes more comfortable, however, some counselors may introduce the idea of group therapy. Group therapy often consists of a small group of clients, usually no more than 10 to 15 in number, who are selected specifically for their varied viewpoints and experiences. Therapists hope that the social interaction and dynamics of group therapy sessions will provide each individual client with much-needed perspective on his or own own circumstances.

One advantage of group therapy is the diversity of opinions. The relationship between an individual client and a therapist can become very insular. Thoughts expressed in these sessions are not often challenged by the therapist, only examined more closely. In a group therapy session, however, each participant is free to challenge or critique another participant's statements, within certain boundaries. An experienced addict in recovery, for instance, may recognize another addict's denial and persuade him or her to face reality. By encouraging diverse opinions, group therapy can effectively motivate each participant towards more honest interaction with others.

Another advantage of group therapy is the social interaction between different ages, cultures and sexes. Many group therapy leaders insist on a form of anonymity and discretion outside of sessions, so each participant is free to assign their own 'identifiers' to other participants. One may represent an oppressive parent, while another may be seen as a spouse. This diversity is helpful for those suffering from social anxiety disorders or self-esteem issues. For example, while in group therapy sessions, a young man suffering from social anxiety disorder may learn how he is perceived by an attractive female, an older parental figure and a male his own age. When participants start to reconcile their irrational beliefs with reality, true emotional healing can begin.

Some participants in group therapy sessions may feel an improved sense of purpose or structure. By attending regularly scheduled meetings, some who suffer from social disorders may feel a sense of belonging. A participant who felt especially needy or helpless one week could become a confident group leader the next week. Participants can use their own strengths to bolster each other during times of crisis. Many people in counseling for anger management or social maladjustment disorders often benefit from group therapy, because they can see others who are facing the same difficulties.

While group therapy may not be an ideal arrangement for all who seek personal counseling, these sessions have proven effective for most participants. Group therapy sessions generally last a few months to a few years, and participation is almost always voluntary. A number of recovery groups, such as Alcoholics Anonymous, use group therapy techniques to help addicts find strength in numbers and realize that they are not alone in the world.