OBJECTIVE: ADHD and Hyperkinetic Disorder (HKD) have the same 18 symptoms, covering inattention (IA), hyperactivity (HYP), and impulsivity (IMP). This study was aimed at providing descriptive scores for the different symptom groups in these disorders and how these scores varied by age and gender, the percentages of individuals meeting the symptom thresholds for the different ADHD types and HKD, the factor structure, and gender invariance of these symptoms in adults. METHOD: To accomplish this, 852 adults provided self-ratings for a scale comprising the 18 ADHD/HKD symptoms. RESULTS: The findings showed that age and gender had minimal effects on the ADHD symptoms. Also, in terms of symptom counts, 2% had HKD and 6.3% had ADHD (inattentive = 1.6%, hyperactive-impulsive = 2.7%, and combined type = 2.0%). Confirmatory factor analysis (CFA) provided most support for the three-factor HKD model, involving separate factors for the IA, HYP, and IMP symptoms. This model showed full measurement invariance across gender. CONCLUSION: The theoretical and clinical implications of the findings are discussed.
To date, at least 12 different models have been suggested for the Strengths and Difficulties Questionnaire (SDQ). The current study used confirmatory factor analysis to examine the relative support for these models. In all, 1,407 Malaysian parents completed SDQ ratings of their children (age range = 5-13 years). Although the findings showed some degree of support for all 12 models, there was most support for an oblique six-factor model that included the five SDQ domains (emotional problems, conduct problems, hyperactivity, peer problems, and low prosocial behavior) and a positive construal factor comprising all the 10 SDQ positive worded items. The original proposed five-factor oblique model also showed good fit. The implications of the findings for understanding the results of past studies of the structural models of the parent version of the SDQ, and for clinical and research practice involving the SDQ are discussed.