Non-Immersive Virtual Environments for the Treatment of Hoarding Disorder

Researchers will compare the effects of VRe to Imagination exposure (Ie) to determine which method is more effective in reducing discarding-related difficulties. The trial is specifically designed for individuals from the general population who do not meet the criteria for hoarding disorder but experience significant emotional discomfort when trying to part with certain belongings. This subclinical presentation of hoarding-like behavior is common and often unaddressed despite its impact on well-being and living space management.

Participants completed online assessments and screening procedures to determine eligibility. They then participated in a one-time, in-lab exposure session using VRe or Ie techniques. Based on a standardized rating scale, each participant brought a personal object they had previously identified as difficult to discard but not overly emotionally charged. During the session, they engaged in either an immersive visualization of discarding the item (Ie) or a guided interaction with a virtual simulation of discarding the item (VRe). Participants were evaluated on psychological (e.g., state anxiety, positive and negative affect) and behavioral outcomes (e.g., actual discarding behavior) before and after the exposure. At the end of the session, participants reported whether they intended to discard the physical object in real life.

This study follows a single-session randomized controlled trial (RCT) design with partial blinding of outcome assessors. While participants were aware of the intervention type they received due to the nature of the exposure task, the researchers responsible for scoring and analyzing outcome data were blinded to group allocation to minimize bias and expectancy effects. This design enhances the rigor and objectivity of outcome comparisons between groups.

This preliminary RCT adopts an exploratory approach due to the limited empirical research on using non-immersive VR for discarding behaviors, particularly in non-clinical populations. Prior findings suggest that VR-based interventions can simulate real-world behavior and reduce emotional reactivity in anxiety-related contexts. However, existing studies have primarily focused on immersive VR applications and clinical populations, such as individuals with specific phobias or PTSD. The current study aims to fill this gap by assessing the potential of non-immersive, more accessible VR platforms in promoting behavioral change related to possession management.

The specific objectives of the study are:

To investigate whether exposure to a non-immersive VR environment can help individuals discard personally relevant objects more effectively than imagination-based exposure; To assess within- and between-group differences in emotional and behavioral responses-specifically state anxiety, positive and negative affect, and discarding behavior-before and after the intervention.

Given the preliminary nature of this research, the following two hypotheses guide the investigation:

Hypothesis 1: Participants in the VR exposure condition will be more likely to discard their object during or after the session than participants in the imagination-based exposure group. This hypothesis is grounded in preliminary evidence suggesting that non-immersive VR can support emotional regulation and task engagement by providing a structured yet low-pressure simulation of real-world scenarios.

Hypothesis 2: Both groups will show a reduction in state anxiety and negative affect, along with a potential increase in positive affect, from pre- to post-exposure. However, participants in the VR condition may exhibit greater improvements due to the virtual environment's interactive and visually grounded features, which may facilitate emotional processing and cognitive restructuring.

Inclusion criteria

Adults individuals from general population.

Exclusion criteria

• A score of 4 or higher on the self-report item of the Hoarding Rating Scale Self-Report, which assesses difficulty in discarding possessions;
• No evident signs of suicidal ideation, based on the scores of the Beck Depression Inventory-II, nor indications of alcohol or substance abuse, psychotic spectrum disorders, depressive disorders, organic mental disorders, or conditions associated with cognitive impairment;
• Participants must report difficulty in discarding certain objects. Moreover, individuals have to complete online monitoring questionnaires via PC or smartphone.
• Participants had to fill out a custom questionnaire evaluating each object based on two parameters: importance and difficulty in discarding.