JMIR Publications

ABSTRACT

Background:

Virtual humans (VHs) have shown increasing promises in the use of assessing, understanding and treating mental health difficulties in virtual reality (VR). However, their design and impact have rarely been the primary focus of mental health research.

Objective:

We provide a systematic review of the use of VHs in immersive VR in applications for mental health, focusing on their roles, interaction types, and the human characteristics being tested.

Methods:

We developed a taxonomy to categorize VHs and conducted a systematic review of 79 studies following PRISMA guidelines.

Results:

VHs were most frequently applied in studies on social anxiety (n = 18), eating disorders (n = 18), and psychosis (n = 15). They were primarily used as active social interaction partners (n = 40), virtual crowds (n = 16), and virtual bodies (n = 23). Explicit interactions dominated active partner studies, while implicit and passive/no interactions were prevalent in crowd and body studies. Over half of the studies (n = 44) manipulated VH characteristics, with body size and gender being the most common variables, and personality explored in fewer studies. Only a limited number of studies provided detailed descriptions of VH appearance and behaviour, with some including still images and videos.

Conclusions:

VHs are versatile and play an important role in mental health VR, but systematic examinations are needed to better understand how their design impacts the outcomes in mental health research. The research community would also benefit from standardized reporting frameworks for VH to enhance reproducibility in future research. Clinical Trial: PROSPERO CRD42021244748