Reinforcement-related cognitive processes, such as reward processing, inhibitory control and social-emotional regulation, are critical brain functions underlying externalising (e.g. ADHD, ODD and CD) and internalising (e.g. anxiety and depression) behaviours. Therefore, compared to the nowadays more common resting-state fMRI and structure MRI, task-based fMRI, joint with the corresponding neuropsychological models, could provide a multiple dimensional and precisive description of a given behaviour, hence facilitating the understanding of the neurobiological bases of its subtype stratification and comorbidity with other behaviours.