Table 2. Characteristics of the interventions of included studies.

Study author & year	Art therapy characteristics	Treatment duration, frequency, type (group or individual)	Co-interventions	Control group characteristics
Henderson et al. (2007)	Mandala creation (represent feelings or emotions related to personal trauma within the contour of a circle).	3 sessions; 20 minutes per session; 3 consecutive days (1 week); group therapy.	None	Active control: Three specific drawing assignments (not trauma related) of 20 minutes each.
Sandmire et al. (2012)	One choice out of five art- making activities: mandala design, free painting, collage making, free clay work and still life drawing; social interaction was allowed, no use of electronic devices.	1 session; 30 minutes; group therapy.	None	Inactive control: Sitting in comfortable chairs, social interaction was allowed, no use of electronic devices
Yu et al. (2016)	Drawing of at least a house, a tree and a person, followed by a group interview.	10 sessions; no set time for drawing; twice a week (5 weeks); group therapy; followed by group interview.	Group interview 40–60 min, 10 sessions, twice a week for 5 weeks.	Active control: Only group interview (40–60 min) twice a week over a period of 5 weeks