Elevated levels of hoarding in ADHD: A special link with inattention

An exploration of neural predictors of treatment compliance in cognitive-behavioral group therapy for hoarding disorder

A persistent and influential barrier to effective cognitive-behavioral therapy (CBT) for patients with hoarding disorder (HD) is treatment retention and compliance. Recent research has suggested that HD patients have abnormal brain activity identified by functional magnetic resonance (fMRI) in regions often engaged for executive functioning (e.g., right superior frontal gyrus, anterior insula, and anterior cingulate), which raises questions about whether these abnormalities could relate to patients' ability to attend, understand, and engage in HD treatment. We examined data from 74 HD-diagnosed adults who completed fMRI-measured brain activity during a discarding task designed to elicit symptom-related brain dysfunction, exploring which regions' activity might predict treatment compliance variables, including treatment engagement (within-session compliance), homework completion (between-session compliance), and treatment attendance. Brain activity that was significantly related to within- and between-session compliance was found largely in insula, parietal, and premotor areas. No brain regions were associated with treatment attendance. The results add to findings from prior research that have found prefrontal, cingulate, and insula activity abnormalities in HD by suggesting that some aspects of HD brain dysfunction might play a role in preventing the engagement needed for therapeutic benefit.

Who really hoards? Hoarding symptoms in adults with attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD) and healthy controls

Although hoarding disorder (HD) is included in the DSM-5 in the obsessive-compulsive and related disorders chapter, in the last few years, HD has been consistently associated with attention-deficit hyperactivity disorder (ADHD). Some studies on HD patients show higher comorbidity with ADHD than with OCD and some studies on ADHD patients found significant higher rates of HD symptoms compared to the general population. However, the aim of the present study was to be the first direct comparison of the prevalence of HD and HD symptoms across adults with a primary diagnosis of ADHD, OCD and a sample of matched healthy controls (HCs).

METHODS

57 adult patients with a primary diagnosis of ADHD and 50 adult patients with a primary diagnosis of OCD were enrolled and matched with 50 HCs. The presence of hoarding disorder and symptoms were assessed though the Saving Inventory Revised (SI-R).

RESULTS

ADHD patients showed significantly higher prevalence of HD comorbidity (32.1%) with respect to both OCD patients (8%) and HCs (4%). The prevalence of HD symptoms was also significantly higher in ADHD patients than in both OCD and HCs. Although OCD patients showed a higher prevalence of HD and HD symptoms with respect to HCs, these differences did not reach statistical significance.

CONCLUSION

HD is significantly more comorbid in ADHD patients than in OCD and HCs. A better understanding and definition of the boundaries between HD and the OCD and ADHD spectrum could lead to the development of a more precise treatment approach for hoarding disorder.

Identifying psychiatric and neurological comorbidities associated with hoarding disorder through network analysis

BACKGROUND

The relationships between hoarding disorder (HD) and other neurological and psychiatric disorders remain largely unknown. Although psychiatric burden in those with HD is high, less is known about neurological disorders. Furthermore, which disorders are primarily associated with HD vs which can be better explained via a relationship with another disorder has not been determined. To address these questions, we examined comorbidity patterns of psychiatric and neurological disorders in a large online registry of adults using network analyses.

METHODS

We first examined psychiatric comorbidity among 252 participants completing clinician administered psychiatric assessments. Using the Brain Health Registry (BHR) (N = 15,978), we next analyzed prevalence of self-reported neurological and psychiatric disorders among participants with no/minimal hoarding, subclinical hoarding, and clinically significant hoarding and used network analyses to identify direct and indirect relationships between HD and the assessed psychiatric and neurological disorders.

RESULTS

The most prevalent comorbidity in clinically assessed participants with HD was major depressive disorder (MDD, 62%), followed by generalized anxiety disorder (GAD, 32%). Network analyses in the BHR indicated that the strongest direct relationships with HD were attention-deficit hyperactivity disorder (ADHD), major depressive disorder (MDD), and obsessive-compulsive disorder (OCD). The relationships between HD and neurological disorders, including mild cognitive impairment, were weak or non-existent after controlling for other disorders.

CONCLUSIONS

ADHD, MDD, and OCD form a triad of psychiatric disorders directly associated with HD. Despite their high comorbidity rates, the associations among anxiety disorders and HD were weak or indirect.