Dimensional thinking in psychiatry in the era of the Research Domain Criteria (RDoC)

Abstract

The biological mechanisms underlying psychiatric diagnoses are not well defined. Clinical diagnosis based on categorical systems exhibit high levels of heterogeneity and co-morbidity. The Research Domain Criteria (RDoC) attempts to reconceptualize psychiatric disorders into transdiagnostic functional dimensional constructs based on neurobiological measures and observable behaviour. By understanding the underlying neurobiology and pathophysiology of the relevant processes, the RDoC aims to advance biomarker development for disease prediction and treatment response. This important evolving dimensional framework must also consider environmental factors. Emerging evidence suggests that gut microbes (microbiome) play a physiological role in brain diseases by modulating neuroimmune, neuroendocrine and neural signalling pathways between the gut and the brain. The integration of the gut microbiome signature as an additional dimensional component of the RDoC may enhance precision psychiatry.

A Systematic Review of Imaging Studies in the Combined and Inattentive Subtypes of Attention Deficit Hyperactivity Disorder

“…Therefore, a brain network-based approach not only can help to advance the neurobiological ADHD framework but could also be useful to further evolve dimensional constructs of ADHD neurobiology. The RDoC framework, which incorporates a dimensional analysis approach, could provide an alternative diagnostic construct based on neurobiological measures and observable behavior to address the primary symptoms that are defined by DSM diagnostic categories (Kelly et al, 2017 ). However, the DSM categorical diagnostic approach currently remains the benchmark for diagnosis in clinical settings, and as such, studies examining the neurobiological features of DSM-based ADHD subtypes offer an opportunity to inform improved clinical approaches.…”

Level of Insight in Patients With Obsessive–Compulsive Disorder: An Exploratory Comparative Study Between Patients With “Good Insight” and “Poor Insight”

“…When they connect with limbic circuits, for instance, they add emotional aspects (rewards) to information and decision making and provide the most diverse forms of behavior (75). The neurobiological dimensional approach recently proposed by the National Institute of Mental Health (76, 77) named Research Domain Criteria () describes that the default mode network, which basically involves brain structures such as medial anterior prefrontal, posterior cingulate cortex, and angular gyrus, is hyperactive in patients with OCD (78, 79). This circuit, in healthy people, becomes more active at rest or when people are asked to reflect on their own thoughts.…”

Cross Talk: The Microbiota and Neurodevelopmental Disorders

“…Furthermore, whether different human donor symptom profiles can be transferred via FMT may further disentangle the contribution of the gut microbiota to the pathophysiology of aspects of psychosis, by attempting to transfer sub-categories of psychotic subjects, including medication free subjects, with different constructs such as negative valance, positive valence, cognitive, social processing and arousal/regulatory systems. While it must be acknowledged that significant neuroscientific advances have frequently been lost in translation and not had appreciable benefits for psychiatric patients as yet, an evolving dimensional framework, consolidating multiple disciplines, and encompassing the gut microbiota as an additional environmental construct linked to other constructs, offers potential to identify sub-groups of patients that may be more likely to respond to a microbiome-based therapeutic approach at specific neurodevelopmental time points (Kelly, 2016 ; Severance et al, 2016c ; Kelly et al, 2017b ).…”