The Annex: 11,868 families, two interviews each, and a diagnosis that came from only one side in 65% to 98% of cases

The Annex reads the method behind the headline. Today’s: researchers led from the University of California San Diego School of Medicine compared what young people and their caregivers say about the same child’s mental health, from age 9 to 17, across a broad range of psychiatric diagnoses¹. The paper was published on 11 November in JAMA Psychiatry¹.

The design. The data come from 11,868 young people and their caregivers in the Adolescent Brain Cognitive Development (ABCD) study, the largest long-term study of children’s brain and behavioural development in the United States¹. Youth and caregivers answered the same diagnostic questions in separate clinical interviews; the researchers derived a DSM-5 diagnosis from each report and tracked the overlap for each diagnosis at different ages¹. Earlier studies, the university says, mostly looked at a few disorders such as depression or anxiety at a single point in time¹. Same questions, two rooms, several years: that is the whole trick, and it is a good one.

The result. Disagreement was the norm. When a diagnosis was reported, it came from only one informant, not both, in about 65% to 98% of cases, depending on the diagnosis and the age¹. Young people were more likely to report major depressive disorder, sleep problems, substance use, suicidal thoughts and attempts, and non-suicidal self-injury; caregivers were more likely to report conduct disorders, eating disorders, and generalised and social anxiety¹. Agreement generally improved with age but stayed limited¹.

The footnote that matters. This study does not tell you who is right. A diagnosis reported by one side only is not automatically false; the point is that each informant sees a different part of the picture, and the authors argue both are needed¹. The university adds that the findings have implications for estimates of how common psychiatric disorders are in young people, and for screening practice¹. Corresponding author Laika Aguinaldo puts it plainly: “If you only ask one, you might miss the opportunity to identify a young person who needs help”¹.

For you. If you are a parent, the uncomfortable line is hers too: on suicidal thoughts, self-harm, substance use and sleep, “most parents don’t actually know”¹. That is not an accusation; it is what privacy at fifteen looks like. The practical lesson is procedural: when a teenager is assessed, it is normal, and useful, for the clinician to speak to them alone.