ADHD symptoms in neurometabolic diseases: Underlying mechanisms and clinical implications

•ADHD symptoms are common in many neurometabolic diseases (NMDs).•Many NMDs affect amino acid, neurotransmitter and energy homeostasis in the brain.•Mechanisms involved in NMD-related ADHD symptoms may be relevant to understand ADHD symptoms more generally.•The detection and treatment of ADHD symptoms in NMDs may be challenging and require particular attention.