Research and Practice Gaps in ADHD and Hoarding Disorder: Scoping Review Protocol

Hoarding disorder is a complex mental health condition that leads to excessive accumulation of possessions, difficulty discarding items, and significant impairment in daily functioning (American Psychiatric Association, 2022; Frost & Hartl, 1996). It is frequently underrecognized in clinical practice (Mataix‐Cols & Fernández de la Cruz, 2018). Research suggests that attention deficit hyperactivity disorder (ADHD) and hoarding disorder often co-occur (Grassi et al., 2023; Morein-Zamir et al., 2021). Adults with both ADHD and hoarding difficulties experience greater impairment than adults with ADHD alone (Grassi et al., 2024). Researchers in this area argue that routine assessment of hoarding disorder should occur among adults with ADHD (Grassi et al., 2024; Morein Zamir et al., 2021), however current practice guidelines for ADHD assessment may not refer specifically to hoarding difficulties, meaning that hoarding difficulties may be overlooked in clinical settings. The objective of this scoping review is to map the evidence regarding the co-occurrence of hoarding disorder and attention-deficit/hyperactivity disorder (ADHD) with a focus on clinical implications, including assessment, and intervention.