Psychopathologie
Inhoudsopgave
,Week 1
Psychiatric diagnosis and treatment in the 21st century:
paradigm shifts versus incremental integration – Stein,
et al.
In the 20th century, psychiatry had shifted away from psychoanalysis and evidence-based
pharmacotherapies and psychotherapies in the treatment of mental disorders were
introduced. These, however, have also been criticised for their medical foundation.
In the 21st century, global mental health has become an influential perspective on mental
disorders and their treatment. Criticism of this perspective argues that Western
constructions are inappropriately exported to the global South.
Nosology The branch of medical science dealing with the classification of diseases.
Psychiatric nosology has been a particular focus of both advances in the field and critiques
from the field. This received its shape in the DSM and ICD.
Despite the growing body of nosological science established by the DSM-5 and ICD-11, many
have argued for new paradigms of classification and assessment.
This paper discusses proposed shifts to several novel perspectives that are argued to have a
significant impact on psychiatric practice and research in the future.
Current models and approaches in psychiatry
Current practice in psychiatry varies in different parts of the world, but there are some
important universalities. Generally, a general training in medicine and surgery is followed by
specialised training in psychiatry. In inpatient settings, psychiatrists are often leaders of a
multidisciplinary team.
A particularly important shift in the 20th century has been the process of
deinstitutionalisation, particularly in high-income countries. Patients moved from specialised
psychiatric hospitals to general medical hospitals, with variable strengthening of community
services.
The DSM system is more commonly used by researchers, while the ICD is a legally mandated
health data standard. The operational criteria and diagnostic guidelines have exerted
considerable influence on modern psychiatry:
- Reliability of diagnosis was increased
- Ability to conceptualise disorders
- Communicate about disorders
- A key role in research
There has also been considerable critique of the reliance of modern psychiatry on the DSM
and ICD.
,Many clinicians and researchers use a biopsychosocial model in thinking about etiology.
However, this approach received significant critique that it is overly broad and vague.
Even though psychiatrists are trained to provide both pharmacological and psychological
interventions, research shows there has been a growing emphasis on pharmacotherapy
interventions. There is considerable evidence of underdiagnosis and undertreatment of
mental health conditions in primary care settings.
Current data points to both a treatment gap and a research-practice gap in mental health.
Treatment gap Findings that, across the globe, many individuals with mental disorders do
not have access to mental health.
Research-practice gap Refers to differences between treatments delivered in standard
care and those supported by scientific evidence. Clinical practitioners have been criticised for
employing an eclectic approach to choosing interventions, for not sufficiently adhering to
evidence-based clinical guidelines, and for not employing measurement-based care.
Given the evidence of underdiagnosis and undertreatment, of misdiagnosis and
inappropriate treatment, and of inadequate quality of treatment, the treatment gap and
research-practice gap are of deep concern.
There are, however, some justifiable reasons for a gap between practice and research:
- The evidence base is relatively sparse for the management of treatment-refractory
and comorbid conditions.
- The relative lack of pragmatic “real-world” research trials in psychiatry.
Clinical neuroscience and personalised pharmacotherapy
A key shift in 20th century psychiatry was from psychoanalytic to biological psychiatry. This
had to do with the discovery of a range of psychiatric medications and advances in
molecular, genetic and neuroimaging methods.
The proposed paradigm of clinical neuroscience rests in part on a critique of current
standard approaches:
- It has been argued that the DSM and ICD constructs are not sufficiently based on
neuroscience.
- There is considerable overlap of genetic architecture across different DSM and ICD
mental disorders.
The proposed new paradigm
views psychiatry as a clinical
neuroscience, which should rest
on a firm foundation of
neurobiological knowledge. The
RDoC project has provided an
influential conceptual framework
for this proposed new paradigm.
, It emphasises domains of functioning that are underpinned by specific neurobiological
mechanisms.
From an RDoC perspective, many mental illnesses can be viewed as neurodevelopmental
disorders, with maturation of the nervous system interacting with a range of external
influences from the time of conception.
Important limitations of the RDoC approach:
- The RDoC seems less an entirely new paradigm than a re-articulation of existing ideas
in biological psychiatry.
- The neurobiology of any particular RDoC construct may be enormously complex, so
that alternative approaches to delineating the mechanisms involved in particular
mental disorders may provide greater traction.
- Methods used to measure domains in the RDoC framework may not be readily
available to clinicians.
The further one moves from academic centres to the practice of psychiatry in primary care
settings around the globe, the less relevant an RDoC framework may be to daily clinical
work.
From an RDoC perspective, particular domains of functioning involve specific neural circuits,
which are in turn modulated by a range of molecular pathways. One notable recent
development in these fields has been a focus on “big data”.
Clinical neuroscience provides an important conceptual framework that may generate some
useful clinical insights, and that may be particularly helpful in guiding clinical research. This
framework has contributed to the reconceptualization of a number of mental disorders and
has on occasion contributed to the introduction of new therapies.
Novel statistical approaches to psychiatric nosology, assessment and
research
Disease taxonomies are particularly complex and may not be able to follow historical models
of scientific taxonomies, which have defined all elements of a given set. Disease taxomonies
have sought to provide a shared, evidence-based, clinically meaningful, comprehensive
classification that is informed by etiology and therapeutics. The notion that underneath the
observable syndrome lies a causal entity, that we should investigate and treat, lies at the
heart of the practice of medicine.
Psychiatry has long faced the challenges of producing a causal nosology that is able to direct
treatment.
HiTOP is a novel paradigm that proposes a hierarchical framework that, based on the
observed covariation of dimensional traits, is able to identify latent super-spectra and
spectra, syndromes, and lower-level components. The key conceptual departure relies on
the premise that, since evidence points toward psychopathological dimensions existing on a
continuum, disorders should be similarly conceptualised, and nosology should move away
from a focus on categorical entities.
