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.
DSM
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.
RDoC
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
DOMAINS
|
RDoC
|
RDoC
DOMAINS
|
|
SYNAPSES
Neurosciences,
Neurocircuitry,
Neuroimaging
Genomics Molecular
Psych.
|
Genes
Molecules
Cells
Neurocircuits
|
Negative
& Positive Valence systems
Arousal
&
Regulatory
systems
|
|
SELF
Child
Development,
Attachment,
Psychodynamics
|
Affiliation
& Attachment
Perception
& Under-
standing
of Self &others
|
Systems
for Social
Processes
|
|
SYSTEMS
AND SOCIETY
Populations,
Culture
Determinants
of Health,
Global
Mental Health
Families,
and Social Systems
|
Social
Communication
|
Systems
for Social
Processes
Cognitive
Systems
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.
