Psychological and electrophysiological indices of inattention in hoarding.

Individuals with elevated hoarding symptoms report elevated symptoms of ADHD and these symptoms are related to impaired daily functioning. Neuropsychological studies have found specific deficits in attention, and a recent review of attentional data from numerous hoarding studies concluded that inattention likely represents an etiological factor in hoarding, rather than a comorbidity. Our study aimed to examine which symptoms of ADHD, inattention or hyperactivity, are related to hoarding symptom severity, and whether individuals with hoarding symptoms display a neurophysiological marker of poor attention (Theta/Beta Ratio; THBR) that might explain these associations. The THBR indexes theta power relative to beta power in the frontal cortex and is often atypical in individuals with ADHD. We hypothesised that individuals would report more severe problems with inattention and would exhibit an elevated theta/beta ratio relative to a healthy control group. We also predicted that any relationship between hoarding and inattention would be independent of anxiety and depression symptoms. 17 hoarding-symptomatic participants and 16 healthy control participants completed self-report measures relating to ADHD, hoarding and general psychopathology, and then underwent resting measures of electroencephalography (EEG). Individuals with hoarding symptoms reported greater difficulties with inattention and hyperactivity, however they did not exhibit an elevated theta/beta ratio. When taking into account recent anxiety and depression, only inattention predicted hoarding symptom severity. Further investigations may help clarify this association and help inform attention-based treatments for hoarding.