Transcript Comorbidity, Prevalance and Trends General Definition of Comorbidity

Comorbidity,
Prevalance and
Trends
General Definition of
Comorbidity
 Historical Origins (Feinstein, 1970)
 General Definition: Two or more physical
illnesses, psychological conditions or a
mix of the two
 Rule rather than the exception
 Distinguish:
 Covariation
 Co-occurrence
Overview of the NCS,
NCS-R
 http://www.hcp.med.harvard.edu/ncs
 National Comorbidity Survey (1990-1992), First
nationally representative survey of mental
disorders using research diagnostic interviews
using DSM-III-R criteria
 National Comorbidity Survey-Replication
(2001-2003), N = 10,000, used DSM-IV criteria
 Follow up on disorders from the first NCS and
to explore particular questions in further depth
Rates of Comorbidity
 Nearly half of all people with a mental disorder
have two or more disorders
 More than half of people with a substance use
disorder and more than 75% of those within
treatment for substance abuse or dependence
als meet criteria for a mental disorder
 Individuals frequently meet criteria for three or
more disorders
 Disorders may have indirect or direct causes—
more on this later
Categorical Versus
Dimensional
 What do you gain with a categorical
system?
 What do you lose with a categorical
system?
 Are categories extreme ends of
continuua or do they represent
something qualitatively different?
 Medical model versus operationalism
Examples of Taxa
 Meehl http://www.tc.umn.edu/~pemeehl/
 asserts that the following disorders may
be true taxons
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Schizophrenia
Bipolar depression
Unipolar major depression
Antisocial personality
Modeling Comorbidity
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Bivariate Comorbidity
Multiformity Models
Causation Models
Independence Models
Spurious Associations
Hypothetical Multivariate Model
Dual Diagnosis: An
application of Comorbidity
 Berken’s Fallacy: Individuals with
multiple disorders are more likely to seek
treatment so that estimates of the
prevalence of comorbid disorders will be
higher in clinical samples
 Inpatient vs Outpatient status
 Chronicity of Illness
 Severity of Illness
Methodological issues
contd
 Definitional issues vary from problem use
of a substance to abuse or dependence
 Which substances are included in the
definition makes a difference
 Disconnected areas of study
Effect of Comorbidity
 Comorbidity affects a disorder’s course
probnosis, assessment, treatment and
outcome
 Dual diagnosis: When a person meets criteria
for one or more Axis I or Axis II mental
disorders and meet criteria for one or more
substance use disorders
 Individuals with a lifetime history of a mental
illness are 2.3 times more likely to have lifetime
alcohol use disorder and 4.5 times more likely
to have a substance use disorder
Disorders with Highest
Comorbidities
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ASP (84%)
Bipolar Disorder (61%)
Schizophrenia (47%)
Panic (36%)
OCD (33%)
MDD 927.2%)
Men and women with PTSD were 5 and 1.4 times more
likely to have a drug use disorder than those without
 Overall mental disorders yield at least double the risk
of a lifetime alcohol or drug use disorder
Overall Rates of
Multimorbidity
 It is not uncommon for patients to have 3
or more disorders: 14% of the NCS
sample had 3 or more diagnoses and
these respondents accounted for almost
90% of the severe 12 month disorders
and well over half of the lifetime and 12
month diagnoses in the sample.
Impact of Dual Diagnosis
 How are patients affected?
 Assessment issues
Underlying theories
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Common Factors
Secondary Substance Abuse
Secondary Psychiatric Disorder
Bidirectional Models
Prevalence and Treatment
of Disorders 1990-2003
 No notable change in the prevalence or
severity of mental disorder in the United States
between 1990-1992 or between 2001-2003
 Most treatment for disorders falls below the
minimal standards of quality
 Treatment typically brief (affects duration of
particular disorder more than prevalence of
mental disorder
 Most treatment delivered in the medical sector
for disorders below clinical threshold.