Toward a transdiagnostic model of common and unique processes leading to the major disorders of childhood: The REAL model of attention, responsiveness and learning.

There is a growing recognition of the importance of identifying both trans-diagnostic risk factors across the major disorders that onset early in childhood, as well as precise vulnerabilities that differentiate among specific disorders. In this paper, we propose a model to explain individual differences in the development of the major forms of mental health problems that can be identified early in life through excesses and deficits in emotional attention, responsiveness and learning (i.e., the REAL model). The model leads to a number of specific hypotheses relating to trans-diagnostic (common to all disorders) and specific risk to the major mental disorders of childhood. Like earlier models of temperament, the REAL constructs are defined in terms of how the child responds to environmental conditions. Our proposal is that the development of psychopathology is in part based on how adverse environmental conditions trigger, inhibit, and interact with these specific biological vulnerabilities at sensitive periods in the developing human. To illustrate this interplay of biology and experience, we summarize key findings from the growing field of epigenetics and child mental health, arguing that epigenetic processes might mediate the relationship between environmental adversity and the major neurodevelopmental systems of REAL. Finally, we argued that the REAL model highlights important avenues for early intervention based on common and unique factors across childhood disorders.