Trans-diagnostic neuroscience of child and adolescent mental disorders: Differentiating decision-making in attention-deficit/hyperactivity disorder, conduct disorder, depression and anxiety.

Ineffective decision-making is a major source of everyday functional impairment and reduced quality of life for young people with mental disorders. However, very little is known about what distinguishes decision-making by individuals with different disorders or the neuropsychological processes or brain systems underlying these. This is the focus of the current review. We first propose a neuro-economic model of the decision-making process with separate stages for: the pre-choice evaluation of expected utility of future options, choice execution and post-choice management, the appraisal of outcome against expectation and the updating of value estimates to guide future decisions. According to the proposed model, decision-making is mediated by neuropsychological processes operating within three domains: (i) self-referential processes involved in autobiographical reflection on past, and prospection about future, experiences; (ii) executive functions, such as working memory, inhibition and planning that regulate the implementation of decisions; and (iii) processes involved in value estimation and outcome appraisal and learning. These processes are underpinned by the interplay of multiple brain networks, especially medial and lateralised cortical components of the default mode network, dorsal cortico-striatal circuits controlling higher-order cognitive and behavioural control, and ventral fronto-striatal circuits, connecting to brain regions implicated in emotion processing, that control valuation and learning processes. Based on clinical insights and considering each of the decision- making stages in turn, we outline disorder-specific hypotheses about impaired decision-making in four childhood disorders: attention-deficit/hyperactivity disorder (ADHD), conduct disorder (CD), depression, and anxiety. We hypothesize that decision-making in ADHD is deficient (i.e., inefficient, insufficiently reflective, and inconsistent) and impulsive (biased towards immediate over delayed alternatives). In CD, it is reckless and insensitive to negative consequences. In depression, it is disengaged, perseverative and pessimistic, while in anxiety it is hesitant, risk-averse and self-deprecating. A survey of current empirical indications related to these disorder-specific hypotheses highlights the limited and fragmentary nature of the evidence base and illustrates the need for a major research initiative in decision-making in childhood disorders. The final section highlights a number of important additional general themes that need to be considered in future research