Date of Award


Publication Type

Master Thesis

Degree Name





ADHD, assessment, clinical neuropsychology, scale development


Erdodi, Laszlo




Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition characterized by a pattern of attentional deficits, hyperactivity, and/or impulsivity that tends to persist into adulthood for a subset of the individuals affected. In an attempt to address the high base rate of feigned ADHD in university settings (estimates ranging from 25 to 50% of those assessed), the objective of the present study was to develop and validate the Hyperactivity/Inattention Trait Scale (HITS), specifically designed to differentiate between feigned and genuine adult ADHD. The HITS was administered online to a sample of undergraduate students, along with several performance validity tests, aimed at detecting non-credible performance. An exploratory factor analysis was conducted in order to examine the underlying structure of the HITS. A seven-factor structure was retained, containing the following factors: executive dysfunction, invalid responding, somatization, impulsivity, hyperactivity, thought disorder, and positive impression management. The HITS demonstrated good classification accuracy in the detection of executive dysfunction (.80 sensitivity, .80 specificity). Importantly, the HITS contains two subscales that approximate the “Larrabee limit” (.50 sensitivity at .90 specificity) in terms of identifying non-credible responding. The combination of the detection of executive dysfunction and non-credible performance allows for the distinction of genuine from feigned symptoms of ADHD in a single selfreport measure.