Neural Mechanisms of CBT Response in Hoarding Disorder

The long-term goal of the proposed research is to improve clinical outcomes for Hoarding
Disorder (HD), a common and potentially debilitating condition that poses a severe public
health burden. The PI has developed and tested a cognitive-behavioral therapy (CBT) that
appears moderately effective, although there is clear room for improvement. In the present
study, the investigators propose to merge this line of research with the PI's recent
NIH-supported neuroimaging research that points to specific functional abnormalities in
regions of interest (ROIs) related to cognitive and affective decisionmaking processes.
Patients with HD n = 80) will be randomized to CBT or wait list (WL). At pre-treatment,
mid-treatment, and post-treatment, patients will undergo functional magnetic resonance
imaging (fMRI) during an acquiring and discarding decision-making task that has been used
successfully in the investigators' previous work. In addition, patients will complete a
number of laboratory tasks designed to assess decision-making capacity and impairment. A
group of healthy control (HC) participants (n = 40) will also complete these measures as a
normative control group. The primary aim of the proposed study is to determine the extent to
which the observed patterns of neural activity in HD change following CBT. Under this aim,
the investigators predict that HD patients (vs.HCs) will show greater hemodynamic activity in
ROIs associated with cognitive and affective aspects of decision-making. The investigators
further predict that HD patients receiving CBT (vs. WL) will show decreased activity in those
ROIs, and will no longer differ from HCs following CBT. A secondary aim of the proposed study
is to determine the relationship between change in activity in brain regions of interest and
hoarding-related symptoms and impairments. The investigators expect, that hemodynamic
activity in the target ROIs will correlate with symptoms of HD and with performance on
decision-making tasks; and that change in brain activity will correspond to both symptom and
mechanism changes over the course of treatment. Finally, an exploratory aim is to explore,
using both data-driven and model-constrained approaches, patterns of pre-treatment neural
activity that predict response to CBT. The investigators predict that among treated HD
patients, pre-treatment activity in the target ROIs will correlate significantly with HD
symptom change from pre- to posttreatment. Results of the proposed study are expected to
elucidate the neural mechanisms of successful response to CBT treatment for hoarding
patients, and to set the stage for further treatment development and possible improvements in
outcome for this disorder.

Inclusion Criteria:

- Aged 20-65

- Hoarding Disorder primary condition

- Score at least 4 on the CGI

- Free from all psychotropic medications for at least 4 weeks(5 weeks for fluoxetine)

- Participant is fluent in English

- Control over current living environment (i.e. not living in a nursing home or with
relatives)

- Physically able to complete therapy assignments (i.e able to discard etc)

- Able to complete study measures

- If female: Using an approved method of contraception

Exclusion Criteria:

- More than 10 sessions of CBT for HD

- Actively suicidality, previous suicide attempt, current use of self harming behaviors
or is at risk for harming others

- Current or past diagnosis of serious psychological disorder (psychotic disorder,
bipolar disorder, substance use disorder or uncontrolled anorexia)

- Psychiatric hospitalization within the past 12 months

- History of anoxic or traumatic brain injury

- Evidence of cognitive dysfunction that would interfere in the ability to provide
informed consent or engage in CBT

- Claustrophobia

- Pacemaker, aneurysm clip, or other metal in the body that would pose a risk during
fMRI?

- If female: Pregnant or lactating