For students with severe attention difficulties, changing school shifts is not the solution

Research involving more than 2,000 Brazilians reveals that while everyone’s performance is consistently lower in the morning, the afternoon shift only improves the performance of students with few or no symptoms of attention deficit hyperactivity disorder.

By Maria Fernanda Ziegler  |  Agência FAPESP – Several studies have shown that students who attend afternoon classes tend to perform better in school than those who attend morning classes. This is due to greater synchrony between class times and students’ biological clocks. However, a study of children and adolescents revealed that this does not apply to students with attention deficit hyperactivity disorder (ADHD) or symptoms of the condition. For this group, changing school shifts does not significantly improve academic performance.

The study involved 2,240 Brazilian students between the ages of six and 14. It evaluated data on reading and writing performance, negative school events (suspension, grade repetition, and dropping out), and ADHD symptoms. The study examined these factors in specific analyses and over a three-year period.

“The results indicate that changing shifts shouldn’t be considered an effective intervention for treating ADHD. For children with attention deficit disorder, studying in the morning or afternoon doesn’t significantly alter academic performance, as the difficulties remain the same,” says Maurício Scopel Hoffmann, head of the Department of Neuropsychiatry at the Federal University of Santa Maria and a researcher at the Institute of Developmental Psychiatry for Children and Adolescents.

A comparison of students with and without ADHD studying in both shifts revealed that afternoon studying improves performance only for students with few or no ADHD symptoms. The morning shift, on the other hand, results in lower performance for all students without exacerbating the situation for those with more significant attention difficulties.

The study was published in the journal European Child & Adolescent Psychiatry and is part of the Brazilian High Risk Cohort Study (BHRCS), an epidemiological study supported by FAPESP that has already evaluated over 2,500 students, aged six to 24, who are at risk of mental disorders in the cities of Porto Alegre and São Paulo.

How to overcome the difficulties

According to data from the Ministry of Health, it is estimated that 7.6% of Brazilian children have neurodevelopmental disorders. The main symptoms are inattention, hyperactivity, and impulsivity. Studies show that children with ADHD may learn more slowly, which can result in difficulty reading, writing, and doing math.

Hoffmann explains that certain non-pharmacological measures can help children and adolescents overcome their difficulties and perform better at school. “Untreated children with ADHD go on to accumulate problems throughout their lives. In addition to getting hurt more often, they tend not to learn at the expected rate, repeat grades, and break out of their social circle. Difficulties at school can have a snowball effect on these individuals, leading to bigger problems such as anxiety and depression in adulthood,” explains the researcher.

“Our initial hypothesis was that the school shift could change the relationship between ADHD and school performance. However, the results showed that there’s a ‘ceiling’ for students with ADHD, meaning that studying in the afternoon isn’t associated with the desired benefits. Students with the disorder had difficulties in the morning and afternoon. Unfortunately, changing the school shift shouldn’t be considered a non-pharmacological measure to overcome the effects of this condition,” he says.

The article “The interplay between ADHD and school shift on educational outcomes in children and adolescents: a cross-sectional and longitudinal analysis” can be read at link.springer.com/article/10.1007/s00787-025-02758-x.