Background: The assessment of emotional expression in patients with ADHD can differ between parent/caregiver and child. Therefore, a new patient-rated version of the Expression and Emotion Scale for Children (EESC) was created and psychometrically analysed.

Methods: This is a 6-month follow-up data analysis of a multicenter, prospective, 12-month observational study in children and adolescents with ADHD. Agreement between the two EESC versions (patient- and parent-rated), internal consistency, sensitivity for changes, floor and ceiling effects as well as test-retest variability were evaluated. The relationship between both EESC scores and the physician-rated ADHD-rating scale (ADHD-RS), Clinical Global Impression of Severity (CGI-S), and General Impression of Percieved Difficulties (GIPD) were also calculated.

Results: 504 patients (mean age 9.6 years) were included and treated with non-stimulant medication (n=252) or stimulant medication (n=247); 5 patients received both medications. The EESC scores decreased similarly for patients and parents and in parallel over time by about 15 points, with the patient EESC scores being always about 3-4 points less than the parent-rated score. Both satisfaction scores increased in parallel by 2-3 points. The agreement and the correlation between the two EESC versions were in a modest range of approximately 0.5 to 0.6 and stable over time. The item-total correlations and analysis of Cronbach's Alpha showed mostly good support of the different items for the total scores, except items 19 and 24 (r<0.1). Ceiling and floor effects and the amount of missing items were limited. Test-retest variability and sensitivity for changes was moderate to excellent (r>0.48). Correlations between the EESC score and other ADHD scales (ADHD-RS, CGI-S) were small to moderate for both ratings. The correlation between the GIPD and the EESC within raters was constant over time (r≈0.5).

Conclusion: This analysis showed that both EESC versions have sound psychometrical properties and can be used in routine settings.

Trial Registration Number: ClinicalTrials.gov Identifier: NCT00540826.