Reaction time variability and attentional impairment in hoarding disorder

18/08/2026

AI Summary

Ex-Gaussian reaction time metrics (tau, sigma, mu) in HD matched those of anxiety and mood and healthy controls, not showing ADHD-like attentional lapses.
Hoarding disorder exhibited significantly greater within-group variance in reaction time metrics than other groups, indicating substantial heterogeneity.
Findings imply possible inattentive and non-inattentive HD subtypes and heterogeneous RT dynamics without generalised attentional slowing.

AI Summary

Attention appears to be impaired in hoarding disorder (HD), although it remains unclear whether this can be conceptualized as co-occurring ADHD or intrinsic to hoarding pathology.

A behavioral index of attentional impairment during decision making, ex-Gaussian modeling of reaction times, has been commonly used as an index of inattention in ADHD, with more skew (i.e., higher tau values) suggestive of attentional lapses.

We used a sample of 43 individuals with hoarding disorder who completed a decision task, comparing their ex-Gaussian reaction time curves, ex-Gaussian vectors, and similarities between them, to samples of individuals high in anxiety and depression ("anxiety and mood", n = 25) and nonclinical controls ("healthy control," HC, n = 39).

Basic summary

Behav Res Ther. 2026 Aug 7;205:105135. doi: 10.1016/j.brat.2026.105135. Online ahead of print.

ABSTRACT

Attention appears to be impaired in hoarding disorder (HD), although it remains unclear whether this can be conceptualized as co-occurring ADHD or intrinsic to hoarding pathology. Self-reported cognitive impairment tends to be inconsistent in HD, with individuals tending to overestimate cognitive impairment compared with performance on neuropsychological tests. A behavioral index of attentional impairment during decision making, ex-Gaussian modeling of reaction times, has been commonly used as an index of inattention in ADHD, with more skew (i.e., higher tau values) suggestive of attentional lapses. We used a sample of 43 individuals with hoarding disorder who completed a decision task, comparing their ex-Gaussian reaction time curves, ex-Gaussian vectors, and similarities between them, to samples of individuals high in anxiety and depression (“anxiety and mood”, n = 25) and nonclinical controls (“healthy control,” HC, n = 39). Results indicated that individuals with HD exhibited tau (and sigma and mu) profiles in their scalar and vectorial metrics that were like those of the AM and HC groups, suggesting a lack of ADHD-like attentional lapses. However, the HD group showed significantly greater within-group variance than the other two diagnostic groups, suggesting substantial within-HD heterogeneity, and possibly implying inattentive and non-inattentive subtypes of HD. Hence, HD shows heterogeneous RT dynamics without generalized attentional slowing.

PMID:42607400 | DOI:10.1016/j.brat.2026.105135

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