BETWEEN DSM AND RDoC: THE SYNAPSES TO SYSTEMS PARADIGM
Psychiatry is a dynamic and rapidly evolving medical speciality. It is now at a transition point in its history. The limitations of the DSM and ICD systems have become apparent while at the same time the promise of the neuroscience paradigm has not yet been realised.
The introduction of DSM III in 1980 has had a profound impact on the practice of psychiatry. DSM III was an improvement from earlier classifications which consisted of imprecise narrative descriptions mixed in with psychoanalytic concepts.
DSM III was atheoretical adopting a phenomenological Kraepelinian approach based on observable surface features. However an objective-descriptive system has intrinsic limitations. Without an explication of the underlying pathophysiology it lacks explanatory power and construct validity. A criterion based system leads to overlap of syndromes and a lack of sharp boundaries between diagnostic entities. This leads to the artificial over diagnosis of “ comorbidities which are identified in 35 to 45% of patients. A model which generates such a high rate of false comorbidity creates difficulty both for research and for clinical practice.
Also the reliance on symptoms and signs, has resulted in a narrowing of clinical focus and an overemphasis on psychopharmacology. The interpersonal and sociocultural frameworks became downgraded.
The high rates of comorbidity and the heterogeneity within diagnostics undermine validity and have made research difficult. Consequently over the past seven years the National Institute of Mental Health has developed the Research Domain Criteria Project. RDoC is based on dimensions of observable behavior linked to neurocircuits.
The purpose of RDoC is to build from the ground up based upon research in molecular biology, genomics, brain imaging and neurobiology. NIMH has identified key domains related to fear, approach, motivation, reward, cognitive systems, social processes (including attachment separation and social dominance) arousal and regulatory systems. The fundamental premise of this approach is that psychiatric disorders are disorders of neurocircuits. This is a long-term open-ended project that by its very nature does not propose a unifying heuristic conceptual model.
There are five Domains in the RDoC matrix:
Negative Valence Systems. Positive Valence Systems. Cognitive Systems.
Systems for Social Processes. Arousal and Regulatory Systems.
RDoC is actually not a classification system but rather an process of research that could lead to a new classification and understanding of psychiatric disorders. RDoC does not have any a priori criteria for defining disorders.
RDoC then is not a system ready for clinical application. It also does not contain any linkages to the broader determinants of health, dimensions of social and environmental factors, that impact on the development of psychiatric disorders.
SYNAPSES to SYSTEMS
In response to the conceptual limitations of DSM and RDoC the psychiatry residency program at McMaster University has introduced a framework known as Synapses to Systems. This consists of a multi-dimensional conceptual model that has application to training and clinical practice.
The Synapses to Systems paradigm identifies four levels of discourse: Synapses, Self, Systems, and Society.
These domains are used to understand psychiatric disorders and to guide therapeutic approaches.
Relationship of Synapses to Systems and RDoC
SYNAPSES to SYSTEMS
Genomics Molecular Psych.
Negative & Positive Valence systems
Affiliation & Attachment
Perception & Under-
standing of Self &others
Systems for Social
SYSTEMS AND SOCIETY
Determinants of Health,
Global Mental Health
Families, and Social Systems
Systems for Social
No domains for broader social factors
The Synapses to Systems approach is a bridge linking the categorical DSM and dimensional RDoC frameworks. It is designed to conceptualize psychiatric disorders, therapeutic strategies and recovery that better equips trainees and practitioners for the future practice of Psychiatry.