It is well established that cultural factors greatly influence mental health as well as the effectiveness of psychosocial treatments. However, all clients might not readily discuss cultural experiences in therapy, a process recently termed cultural concealment. Drinane et al. (2018) introduced the concept of cultural concealment and found a significant within-therapist and between-therapist effects of clients’ cultural concealment and their perceived improvement in therapy. Despite an extensive literature on multicultural group work and recent developments in assessing cultural processes within therapy groups, there is a paucity of research examining the process of cultural concealment in therapy groups. Informed by social norm theory and the multicultural group literature, this study examined within-group and between-group effects of clients’ cultural concealment and their perceptions of improvement, group cohesion, and a global therapeutic factor. Data consisted of 341 clients across 81 interpersonal process therapy groups. Results indicated significant within-group cultural concealment effects for clients’ perceptions of improvement, group cohesion, and a global therapeutic factor. In contrast, between-group cultural concealment effects were only found for clients’ perceptions of a global therapeutic factor. These findings suggest that group members’ own cultural concealment is negatively associated with their perceptions of improvement, group cohesion, and a global therapeutic factor, whereas the group-as-a-whole’s cultural concealment is negatively associated with members’ perceptions of a global therapeutic factor. Group therapists should be cognizant of the consequential effect of cultural concealment at the member and group level to enhance the effectiveness of group treatments for all clients.

This study suggests that clients who experience group therapy as an unsafe space to share parts of their cultural identities experience group therapy as less effective. This indicates that interventions in group therapy designed to help clients bring their true selves into the therapy room can...