Building Community-Academic Partnerships for the Evidence-Based Treatment of Hoarding Disorder
Phase: NA
Conditions: Hoarding Disorder, Hoarding, Clutter
Sponsor: Stanford University

Date: November 11, 2025 
Study Title:  Enhancing Treatment of Hoarding Disorder With Personalized In-Home Sorting and 
Decluttering Practice 
NCT02843308 
Scientific background: 
 
Hoarding disorder (HD) is characterized by persistent difficulties parting with possessions, 
associated distress, and clutter that compromises the intended use of living spaces (American 
Psychiatric Association, 2022). HD is common, with an estimated overall pooled prevalence 
of 2.5% of the general population (Postlethwaite et al., 2019). HD causes significant impacts on 
social, occupational, and other important areas of functioning and health risks include falls and 
other injuries due to clutter (American Psychiatric Association, 2022). In severe cases, home 
fires and pest infestation extend health and safety risks to neighbors (Frost et al., 2000). HD is 
associated with significantly lower quality of life, social isolation, and high rate of co-occurring 
mental disorders (Frost et al., 2011a; Ong et al., 2015; Saxena et al., 2011; Tolin et al., 2019). 
Cognitive behavioral therapy (CBT) for hoarding symptoms has shown promise when delivered 
by a trained therapist in either individual or group settings (Tolin et al., 2015); however, cost 
and access to a therapist may be barriers for some (Thompson et al., 2017). One alternative is 
the Buried in Treasures [BIT] Workshop, an evidence-based, highly structured, short-term, 
skills-based group using CBT principles but led by peers (Frost et al., 2012a) or non-professional 
facilitators (Frost et al., 2011a). To date, studies have shown BIT can significantly reduce 
hoarding symptoms when compared to a waitlist control (Frost et al., 2012a) and is as effective 
as psychologist-led group CBT (Mathews et al., 2016). Despite these promising results, many 
continue to have impairing symptoms after treatment and high levels of clutter, regardless of 
modality or type of facilitator (Moulding et al., 2017; Tolin et al., 2015) and under-utilize HD 
treatments and services (Frost et al., 2012b). Approaches that enhance the clinical effects of 
these interventions are needed. Based on two studies—one reporting that personalized care 
and accountability made treatments more acceptable to individuals with hoarding disorder 
(Rodriguez et al., 2016) and another reporting that greater number of home sessions were 
associated with better clinical outcomes (Tolin et al., 2015)—we tested the feasibility and 
effectiveness of adding personalized, in-home uncluttering sessions to the final weeks 
of BIT with up to 20 hours of supervised in-home uncluttering practices in a small (N = 5) pilot 
study of BIT+ (Linkovski et al., 2018). Reductions in hoarding symptoms, clutter, and 
impairment of daily activities were observed. Treatment response rate was comparable to rates 
in other BIT studies, with continued improvement in clutter level after in-home uncluttering 
sessions (Linkovski et al., 2018). Although the pilot study of BIT+ was promising, it had 
limitations including the small sample size and open-label design. To build upon 
this small pilot, we tested BIT+ in a larger sample using a randomized waitlist-controlled trial 
design and hypothesized that individuals randomized to BIT+ would have more significant and 
more substantial benefits on hoarding symptoms than patients randomized to an 18-week 
long waitlist. After the waitlist, participants were offered BIT+, and the BIT+ completer sample 
was pooled to allow us sufficient sample size to estimate clinical benefits.  

 
Objectives: 
To test BIT+ in a larger sample using a randomized waitlist-controlled trial design; we 
hypothesize that individuals randomized to BIT+ will have more significant and more substantial 
benefits on hoarding symptoms than patients randomized to an 18-week long waitlist. 
 
Design:  
This randomized waitlist-controlled trial with 1:1 (BIT+ intervention; waitlist control) allocation was 
conducted at an academic outpatient research setting. Potential participants were recruited via study 
advertisements posted online and in the local community, radio ads, and by referrals from mental 
health professionals and local hoarding task forces between October 2016 and June 2019. The study 
protocol was approved by the Stanford Institutional Review Board (IRB), and participants provided 
written informed consent. The trial was prospectively registered; clinicaltrials.gov identifier: 
NCT02843308. Participants were randomized by group, employing random permuted blocks within a 1:1 
allocation ratio between intervention and waitlist control groups. The group therapy facilitators could 
not be blinded to allocation for practical reasons; the independent evaluators who assessed home 
clutter levels were blinded to allocation. Although several trial designs (with an active comparator) were 
considered, limited resources prohibited these options. A waitlist-controlled trial design was selected 
given treatment could be delivered to all participants, while controlling for passage of time and allowing 
comparison to a prior study of BIT that also employed a waitlist control condition (Frost et al., 2012a). 
Methods: 
a) Inclusion and Exclusion Criteria 
Eligible adults (ages 18–70) had a primary diagnosis of HD according to DSM-5 criteria (American 
Psychiatric Association, 2013) as assessed via structured clinical interview (SCID) (First et al., 2015), with 
clinically significant hoarding disorder (Saving Inventory-Revised [SI-R] ≥ 41) (Frost et al., 2012b), clutter 
that impaired living spaces (Clutter Image Rating [CIR] ≥ 4) (Frost et al., 2008), no or stable psychotropic 
medication use (defined as medication doses unchanged for >4 weeks prior to assessment or > 8 weeks 
if fluoxetine). Potential participants were excluded if they lived greater than 30 miles from Stanford 
University (because the study necessitated home visits), had OCD as a primary diagnosis, a current or 
history of psychotic disorder or bipolar disorder, a current eating disorder, a current moderate or 
lifetime severe substance use disorder or were severely depressed (Hamilton Depression Rating Scale 
>30) (Hamilton, 1960), at risk of suicide (Columbia-Suicide Severity Rating Scale ≥4) (Posner et al., 2011) 
or any other medical or neuropsychiatric condition increased risk of participation or would prevent 
completion of study procedures. Additionally, we excluded participants who were unwilling to have 
unclutter volunteers enter their home, were unable to follow study procedures, had clutter levels with 
the potential for objects falling from overhead (CIR >8; approximately above shoulder height or higher), 
had evidence of animal hoarding or pest infestation, or were at high risk of eviction due to legal 
proceedings that necessitated a higher level of care. Individuals who had started working with a 
professional organizer or cognitive behavior therapist for HD within 8 weeks of enrollment were also 
excluded. 
b) Procedures 

Participants made 20 study-related visits to the study site: a baseline visit at the study start, 18 weekly 
visits for the BIT+ intervention, and a close-out visit at the study’s completion. The BIT+ intervention 
consisted of 16 weekly group BIT workshop and 20 h of in-home uncluttering sessions over 18 weeks. 
The study procedures were identical to the pilot study (Linkovski et al., 2018), with two exceptions 
based on participant feedback and expert input from LS, RF, and CIR: a) rather than including a one-
week break during Week 9 and a two-week break during Weeks 16–17, we continued weekly meeting 
uninterrupted to improve consistency; b) instead of concentrating the uncluttering at the end of the 
study with four weeks of twice weekly uncluttering, we slowly titrated up the duration and intensity 
over the last eight weeks to build up uncluttering stamina. The BIT workshop sessions are 2 hours long 
and structured based on the book, Buried in Treasures: Help for Compulsive Acquiring, Saving and 
Hoarding (Tolin et al., 2014) and the BIT facilitator’s guide (Shuer and Frost, 2016). Each session was led 
by two trained, non-professional group facilitators and include HD-specific psycho-education, identifying 
acquisition triggers, tolerating urges to acquire, and developing skills for parting with possessions, 
following the methods of Frost et al. (2012a). For the uncluttering sessions, pairs of trained non-
professional uncluttering volunteers made weekly home visits to each participant’s residence for 10 
visits of 2 hours each (20 hours of in-home uncluttering sessions over 18 weeks). The content of the 
sessions closely modeled content that participants learned during the BIT workshop and included the 
structured exercises detailed in the Buried in Treasures workbook (Tolin et al., 2014) and the BIT 
facilitator’s guide (Shuer and Frost, 2016). As described previously (Linkovski et al., 2018), each session 
included a check-in, facilitated uncluttering time, and a closing in which participants shared their 
reflections and their objectives for the coming week. 
Statistical Plan (including considerations for analysis): 
Baseline variables will be assessed using descriptive statistics for the BIT+ and watilist groups using 
means and standard deviations for the continuous, and frequencies and percentages for categorical 
variables.  
We will employ standard linear mixed effects modeling (e.g., Bryk and Raudenbush, 2002; Singer and 
Willett, 2003) to estimate and compare the change from the pre-to post-treatment assessment during 
the first segment of our study in line with the intention to treat principle. The use of mixed effects 
modeling was chosen because this approach is better at handling missing data and yields improved 
power compared to linear regression. Specifically, we used a random intercept model assuming linear 
change. We will use maximum likelihood estimation with robust standard errors implemented in Mplus 
Version 8.4 (Muth´en & Muth´en, 1998–2017). Data points that are missing due to subject attrition will 
be handled assuming that data are missing at random (MAR; Little and Rubin, 2019) conditional on 
observed information. In our mixed effects analyses, the change (slope) in the outcome will be modeled 
as the key dependent variable predicted by the treatment assignment status. In particular, the change in 
SI-R total from baseline to end of treatment will be assessed. Specifically, will report the number of 
participants who met and exceeded the response criteria of the SI-R total (SI-R reduction ≥14 points). 
In all analyses, we will use the nominal significance level (α = 0.05). We will not adjust the significance 
level for multiple testing given that we had one clear primary endpoint. We will analyze several 
secondary outcomes including subscales of SI-R. We applied the same analytical strategy to analyze the 
data from the second segment of our study, where the individuals assigned to the waitlist condition 

receives BIT+. Additionally, we will compare the first and second segments in terms of the estimated 
changes under BIT+ treatment.