Are all the 18 DSM-IV and DSM-5 criteria equally useful for diagnosing ADHD and predicting comorbid conduct problems?

Abstract

In view of ICD-11 revision, we evaluate whether the 18 DSM-IV diagnostic items retained by DSM-5 could be further improved (i) in predicting ADHD 'caseness' and 'impairment' and (ii) discriminating ADHD without CD (ADHD - CD) cases from ADHD with CD (ADHD + CD) cases. In a multi-centre study sample consisting of 1497 ADHD probands and 291 unaffected subjects, 18 diagnostic items were examined for redundancy; then each item was evaluated for association with caseness, impairment and CD status using Classical Test Theory, Item-Response Theory and logistic regression methods. First, all 18 DSM-IV items contributed significantly and independently to the clinical diagnosis of ADHD. Second, not all the DSM-IV items carried equal weighting. "Often loses things", "forgetfulness" and "difficulty sustaining attention" mark severity for Inattentiveness (IA) items and "often unduly noisy", "exhibits a persistent pattern of restlessness", "leaves seat in class" and "often blurts out answers" for Hyperactivity/Impulsivity (HI) items. "Easily distracted", "inattentive to careless mistakes", "often interrupts" and "often fidgets" are associated with milder presentations. In the IA domain, "distracted" yields most information in the low-severity range of the latent trait, "careless" in the mid-severity range and "loses" in the high-severity range. In the HI domains, "interrupts" yields most information in the low-severity range and "motor" in the high-severity range. Third, all 18 items predicted impairment. Fourth, specific ADHD items are associated with ADHD + CD status. The DSM-IV diagnostic items were valid and not redundant; however, some carried more weight than others. All items were associated with impairment.

Hierarchy and Psychometric Properties of ADHD Symptoms in Spanish Children: An Application of the Graded Response Model

“…Regarding the possible implications for the review of ADHD symptomology, the symptoms “Loses things necessary for task or activities” on the IA scale and “Talks excessively” and “Blurts out answers before questions have been completed” on the HI scale present relatively low discrimination values than the other symptoms as well as poor information and the lowest reliability values of all of the levels for the respective latent traits. These results partially replicate previous findings revealing relatively low discriminative values for the symptoms “loses things” [ 5 , 8 , 22 , 26 , 29 ], “talks excessively” [ 5 , 8 , 22 , 24 ] and “blurts answers” [ 8 , 24 , 29 ]. Nevertheless, relatively high levels were maintained.…”

“…These findings also support the appropriateness of reducing the list of symptoms to just include those with greater discriminatory capacity, thereby resulting in a more parsimonious diagnostic process. Additionally, based on recent evidence showing that some symptoms do have more predictive power on both diagnosis and impairment level [ 29 ], our results suggest that reducing the scale without losing relevant information would allow it usage as a screening tool. Interestingly, previous studies reveal that certain symptoms (e.g.…”

“…Despite the increasing usage of IRT for assessing non-cognitive symptoms [ 18 ], studies using this approach for analyzing ADHD are scant (e.g., [ 19 – 25 ]), as compared to the great amount of studies based on analytic approaches such as confirmatory factor analysis. Overall, IRT-based studies have been focused on the calibration of the scales based on 18 ADHD symptoms in general/community [ 5 , 22 – 24 , 26 – 28 ], and mixed clinical/general samples [ 8 , 29 ], and also on the assessment of differential functioning (DIF) of symptoms considering gender, the age of onset, and the informant (parents and teachers). The main findings of these studies are: (a) as a whole, the psychometric properties of the rating scales based on 18 DSM symptoms are adequate either in the case of parents or teachers; (b) the symptom’s capability to provide accurate information differs along the continuum; (c) the general reliability of the instrument is low for extreme values of the latent variable, and high approximately from the mean to two standard deviations; (d) the symptoms are not equivalent in terms of severity; and (e) certain symptoms seems to function differentially for both gender and age; however because these results vary across studies there is no robust evidence showing that none of them present systematic invariance difficulties.…”

Evaluating the Hierarchical Structure of ADHD Symptoms and Invariance Across Age and Gender

“…Despite substantial evidence supporting the use of the bifactor model for ADHD symptoms, existing studies that used IRT set forward either a single unidimensional model for all ADHD symptoms, or separate unidimensional models for inattention and hyperactivity/impulsivity (Garcia-Rosales et al, 2015; Gomez, 2008; Li, Reise, Chronis-Tuscano, Mikami, & Lee, 2015; Purpura, Wilson, & Lonigan, 2010). While assumptions of unidimensionality of ADHD symptoms may be appropriate for nonclinical samples (Arias et al, 2016), the multidimensionality that is observed in clinical samples and associated unmodeled residual dependence between items may result in biased parameter estimates (Chen & Thissen, 1997), and overestimation of IRT item information and test reliability (Sireci, Thissen, & Wainer, 1991).…”

A network analysis approach to ADHD symptoms: More than the sum of its parts

“…An alternative novel approach is to view ADHD as a network of interacting symptoms, providing detailed information on the complex relations between symptoms. While all 18 of the DSM symptoms contribute significantly and independently to the disorder [7], given the heterogeneity of the ADHD presentation, identifying symptoms that are central to the disorder have multiple implications including better understanding aetiological factors associated with the disorder, increasing accuracy in predicting outcomes and informing treatment approaches.…”