New evidence supports use of A-TAC to guide early assessment for children in mental health services
A new study highlights A-TAC as an effective guide for early assessment in child mental health services
In recent years, Sweden — like many countries — has seen a surge in referrals to Child and Adolescent Mental Health Services (CAMHS). Many children are being sent for specialist assessment, even though not all require such in-depth evaluation. Reliable screening tools can help direct children to the right level of care more efficiently, freeing up resources for those who need specialised support.
A major Swedish study has confirmed that a widely used comprehensive assessment tool containing 96 questions— the Autism-Tics, ADHD, and other Comorbidities Inventory (A-TAC) — is an effective way to screen children for a range of major neurodevelopmental conditions such as autism and ADHD. The A-TAC is a telephone interview developed by Christopher Gillberg and his group at Gothenburg University for use in the CATSS (Child and Adolescent Twin Study in Sweden). It can be used by non-child-psychiatrists.
The research, published in BMC Psychiatry by the University of Gothenburg and other Swedish institutions, tested how well the A-TAC could identify children with clinical diagnoses when compared to full psychiatric evaluations.
What the study did
The researchers drew participants from the Child and Adolescent Twin Study in Sweden (CATSS) — a long-term project that follows thousands of twins nationwide. For this study, the team focused on 263 children aged 9–10, including both children who had screened positive for potential neurodevelopmental issues and small number of children who had screened negative.
Each child underwent a thorough clinical evaluation by trained psychologists and psychiatrists — including structured interviews, standardised questionnaires, and intelligence testing. Importantly, these clinicians did not know the children’s A-TAC scores beforehand.
The team then compared the A-TAC screening results with the official clinical diagnoses to measure how accurately the tool could detect different disorders.
Key findings
The A-TAC proved to be a reliable screening tool for most neurodevelopmental conditions, such as autism spectrum disorder (ASD), ADHD, and tic disorders. Its accuracy (measured by “area under the curve,” or AUC) ranged from 0.81 to 0.96 for most diagnoses — considered “good” to “excellent” in psychometric terms.
However, the tool was less reliable for detecting developmental coordination disorder (DCD), a motor skills condition that often receives less public and clinical attention.
Importantly, the study found that over 40% of children diagnosed with one neurodevelopmental condition also met criteria for at least one other. For example, children with ADHD often also had symptoms of anxiety, tics, or autism traits. This reinforces the idea that clinicians should take a broad, comprehensive view when assessing children, rather than focusing on a single issue.
What the results mean
The findings suggest that the A-TAC is an effective way to distinguish between children who likely need specialist evaluation and those who do not. Still, the authors caution that the tool cannot replace a full clinical assessment.
“A-TAC can help identify neurodevelopmental problems in both clinical and population-based settings,” said Professor and psychologist Sebastian Lundström, Gillberg Neuropsychiatry Centre. “But it should never be used to decide whether an individual should have access to specialist care.”
The researchers also noted that while ADHD and autism were relatively well detected, motor coordination difficulties (DCD) were often overlooked. They suggest that parents and professionals may confuse clumsiness with inattention or simply lack awareness of DCD as a diagnosis.
Limitations and future directions
Not every invited family took part, and the study mostly included children from Sweden’s most populated regions, meaning results may not fully represent rural areas. Some conditions, such as eating disorders and intellectual disability, were too rare in this age group for firm conclusions.
The team hopes future research will explore how A-TAC results relate to children’s later outcomes — such as education, mental health, and social functioning — as they grow older.
Takeaway message
This study supports the A-TAC as a useful, research-backed screening tool that can help identify children who may benefit from further assessment for conditions like ADHD and autism.
At the same time, the findings highlight the complex overlap among developmental and mental health conditions — and the importance of comprehensive, individualised evaluations for children showing early signs of difficulty.
Article: Halldner, L., Eberhard, S., Lichtenstein, P. et al. Thorough clinical child psychiatric diagnostic evaluation and validation of the Autism- Tics, ADHD and other comorbidities inventory (A-TAC) in a population-based sample of 9-year-olds. BMC Psychiatry 25, 918 (2025). https://doi.org/10.1186/s12888-025-07475-y
Text written by Anna Spyrou, Communications Officer
