Age-dependent and -independent changes in attention-deficit/hyperactivity disorder (ADHD) during spatial working memory performance

Abstract

Objectives: Attention-deficit/hyperactivity disorder (ADHD) has been associated with spatial working memory as well as frontostriatal core deficits. However, it is still unclear how the link between these frontostriatal deficits and working memory function in ADHD differs in children and adults. This study examined spatial working memory in adults and children with ADHD, focussing on identifying regions demonstrating age-invariant or age-dependent abnormalities. Methods: We used functional magnetic resonance imaging to examine a group of 26 children and 35 adults to study load manipulated spatial working memory in patients and controls. Results: In comparison to healthy controls, patients demonstrated reduced positive parietal and frontostriatal load effects, i.e., less increase in brain activity from low to high load, despite similar task performance. In addition, younger patients showed negative load effects, i.e., a decrease in brain activity from low to high load, in medial prefrontal regions. Load effect differences between ADHD and controls that differed between age groups were found predominantly in prefrontal regions. Age-invariant load effect differences occurred predominantly in frontostriatal regions. Conclusions: The age-dependent deviations support the role of prefrontal maturation and compensation in ADHD, while the age-invariant alterations observed in frontostriatal regions provide further evidence that these regions reflect a core pathophysiology in ADHD.

Keywords:

• ADHD
• functional magnetic resonance imaging
• spatial working memory
• prefrontal cortex
• basal ganglia

Acknowledgements

We thank our participants and their parents for the participation in our study. We also thank Dr Hanna Christiansen for providing the unpublished CAARS questionnaires and normative data, and Hana Burianova for her suggestions on improving the manuscript. This cooperative project was funded by the University Research Priority Programme “Integrative Human Physiology” and supported by the Swiss National Foundation Sinergia Grant CRSII3_136249.

Steffen Bollmann reports no financial relationships with commercial interests.

Carmen Ghisleni reports no financial relationships with commercial interests.

Simon-Shlomo Poil reports no financial relationships with commercial interests.

Ernst Martin reports no financial relationships with commercial interests.

Juliane Ball reports no financial relationships with commercial interests.

Dominique Eich-Höchli reports no financial relationships with commercial interests.

Peter Klaver reports no financial relationships with commercial interests.

Ruth O'Gorman reports no financial relationships with commercial interests.

Lars Michels reports no financial relationships with commercial interests.

Daniel Brandeis reports no financial relationships with commercial interests.

Steffen Bollmann had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Statement of interest

None to declare.