University of Wollongong research has raised concerns about the consistency of ADHD diagnoses, with findings suggesting that many psychologists may not be fully adhering to established clinical guidelines.
The study found that while approximately 75 per cent of psychologists reported following diagnostic guidelines, while less than half (48.6 per cent) consistently applied all recommended assessment components in their practice.
This gap highlights a discrepancy between what clinicians believe they are doing and what is actually occurring during assessments.
Note: Reported vs actual adherence to ADHD diagnostic guidelines
Surveying 322 psychologists, the research also revealed inconsistencies in how ADHD is evaluated.
High reliance was placed on self-report measures, used by between 87 per cent and 97 per cent of respondents, while more objective tools, such as psychometric testing, were used less frequently, ranging from 46 per cent to 54 per cent.
The use of medical assessments varied widely, from zero to 68 per cent, indicating a lack of standardisation across the field.
Alarmingly, fewer than one-third of respondents were able to correctly identify all core ADHD diagnostic criteria, raising further concerns about diagnostic accuracy.
Only 31.6 per cent of clinicians demonstrated full understanding of the required criteria, suggesting potential gaps in professional knowledge and training
Note: Types of assessment tools used in ADHD evaluations
UOW lead researcher on the project, Clare O’Toole has warned that inconsistent practices could have serious consequences for patients.
“People may be misdiagnosed with ADHD, while others may miss diagnoses that would be appropriate,” she said.
“Delayed or misdiagnosis can impair social, physical, and mental health and prevent people from accessing helpful treatments.”
The findings have pointed to broader concerns about the reliability of ADHD assessments, particularly as diagnoses continue to rise globally.
University of Sydney epidemiologist Dr Luise Kazda said there was a lack of strong empirical evidence in ADHD diagnosis.
Dr Kazda told the Royal Australian College of General Practitioners that much of the discussion around ADHD is driven by opinion, rather than rigorous data.
Her research found “convincing evidence” that ADHD may be overdiagnosed, particularly in children with milder symptoms, and highlights that diagnosis rates and medication use have increased over time.
Dr Kazda has warned that lowering diagnostic thresholds can lead to more children being labelled with ADHD, even when symptoms fall on the borderline of normal behaviour.
“There’s a lot of opinion pieces, but very little evidence,” she said.
The UOW research also found that ADHD diagnoses have increased worldwide since the 1980s.
Variability in assessment methods may increase the risk of both overdiagnosis and underdiagnosis, affecting an individuals’ access to support, medication, and educational accommodations.
The study highlights what researchers describe as a “significant gap” between expected clinical standards and real-world practice.
This suggests a need for improved training, clearer guidelines, and more consistent use of evidence-based assessment tools.
