On the validity of neurodevelopmental disorders

Author

Summary, in English

Abstract



Introduction: Validity is important at different levels in psychiatry. Valid structured instruments are important aids in screening and diagnostics, in both research and clinical practice. An aim of the diagnostic procedure is to yield valid diagnoses. Ultimately, the validity of structured instruments (non-empirical) and clinical diagnoses depends on the validity of the diagnostic classification system and its constructs.



Aims and methods: (1) To validate the Autism – Tics, ADHD, and other Comorbidities inventory (A-TAC), developed for screening in large-scale studies, against clinical diagnoses and an established screening instrument (Child Behavior Checklist [CBCL]). (2) To determine prevalence rates and distributions of neurodevelopmental problems (NDPs) and general psychiatric problems as well as patterns of co-occurrence in a general population sample according to the A-TAC. (3) To qualitatively explore patients’ own experiences of being diagnosed with ADHD as an adult in an attempt to validate the diagnosis from a patient perspective.



Results: The A-TAC showed excellent inter-rater reliability (ICC ≥0.97). ICCs for test-retest reliability were 0.77-0.97 for most modules. AUCs were around 0.90 for autism spectrum disorders (ASDs) and ADHD, and 0.71-0.84 for the other NDPs. Optimal cut-offs gave sensitivity around 0.90 and specificity around 0.75 for ASDs and ADHD. Cohen’s κ was > 0.60 for ASDs and ADHD. Sensitivity and Cohen’s κ were lower for the other NDPs. The A-TAC had moderate convergent validity with the CBCL on subscales that tended to target the same areas, but provided a more detailed and specific assessment of ASDs and related NDPs. Problems were continuously distributed and highly inter-correlated across types. There was a complex intra- and inter-individual variation of experiences of being diagnosed with ADHD, focused on diagnosis, identity, and life, but positive experiences were dominant. All but one interviewee expressed important positive consequences of being diagnosed. About half of them acknowledged negative aspects, but none regretted going through the neuropsychiatric evaluation.



Conclusions: The results support the reliability and validity of the A-TAC in identifying ASDs, ADHD, and common comorbid NDPs. From a patient perspective, an ADHD diagnosis brings major benefits compared to the undiagnosed situation. Knowledge of an individual’s experiences is important for professionals as they can affect well-being and interfere with different treatments. Negative experiences especially might need to be addressed in the treatment work. Using the patient’s perspective may help validate psychiatric diagnoses, and is consistent with the idea of incorporating consequences into the concept of validity.

Topic

  • Psychiatry

Keywords

  • Validity
  • screening
  • comorbidity
  • patient experience
  • neurodevelopmental disorders
  • autism
  • ADHD
  • A-TAC
  • reliability

Status

Published

ISBN/ISSN/Other

  • ISSN: 1652-8220
  • ISBN: 978-91-7619-226-9

Defence date

7 January 2016

Defence time

13:00

Defence place

CRC auditorium, ingång 72, Skånes universitetssjukhus i Malmö