Spontaneous theory of mind in adults with attention-deficit/hyperactivity disorder.

Spontaneous theory of mind (ToM) is an unconscious and automatic understanding of others' mental states. Recently, individuals with attention-deficit hyperactivity disorder (ADHD) have been shown to have social and communication difficulties, and ToM in ADHD has come under scrutiny. Although some studies have employed explicit ToM tasks to this end with contradictory results, none, to our knowledge, has investigated spontaneous ToM in individuals with ADHD. Therefore, we performed this study to examine implicit mentalizing in adults with ADHD using the anticipatory-looking paradigm designed by Senju et al. (2009) with a sample of 24 adults with ADHD and 18 neurotypical adults. The total fixation times to three areas of interest, i.e., the actor and the false-belief congruent and incongruent sides of the scene were measured. We found that neither group showed looking bias toward either the false-belief congruent or incongruent side. We interpret that this similar gaze pattern and the absence of looking bias to the false-belief incongruent side in both groups is indicative of intact implicit ToM in adults with ADHD. Adults with ADHD looked significantly less at the actor than did neurotypical individuals, possibly due to inattention and further experimental modifications should be considered.