Transcript Classification of Mental Disorders. Classification of Mental Disorders . • All systems of mental disorders and diagnosis stem from the work of Kraepelin.  He.

Classification of Mental
Disorders.
Classification of Mental Disorders
.
• All systems of mental disorders and diagnosis stem
from the work of Kraepelin.
 He claimed certain groups of symptoms often occur
together, thus allowing us to call them diseases or
syndromes.
 He regarded each mental illness as distinct from all
others with its own origins, symptoms, course, and
outcomes.
Classification cont…
• He originally classified two major groups:
 Dementia praecox (Schizophrenia)
 Manic-depressive psychosis (faulty metabolism).
• This helped to establish the organic nature of mental
disorders and formed the basis of the Diagnostic
Statistical Manual of Mental Disorders (DSM).
•
The APA’s official classification system
Classification cont..
• The International Classification Of Diseases (ICD) published by the World Health Organisation (WHO)
• This classification is also embodied in the Mental
health Act (1983). The act contains three major
categories of mental disturbances:
• Mental illness, Personality disorder, and Mental
impairment.
DSM-IV-TR & ICD-10.
• DSM-IV-TR
• Larger no. of discrete
categories.
• Uses a multi-axial
system.
• Uses term psychotic.
• ICD-10
• More general
categories.
• Generally single axis.
(But uses broad aetiology).
• Uses term neurotic.
DSM-IV-TR
The inclusion of the axes reflect the assumption that
most disorders are caused by the interaction of:
• Biological
• Sociological
• Psychological factors.
 The patient is assessed more broadly giving a more
global in-depth picture.
DSM-IV-TR (1994)
Ø Effort to develop a consistent worldwide system of
classification that would be compatible with the ICD10.
Ø Extensive review of all research on psychopathology
to update the classification system.
Ø Distinction between organically based disorders and
psychologically based disorders was eliminated.
Ø Increased considerations of cultural factors.
Diagnostic Assessment: Clinical History
 Onset, duration and
severity of current
symptoms
 Previous mental illness
 Medical history
 Childhood history
 Occupational
functioning
 Educational history
 Marital and
relationship history
 Family history
 Religion
 Psychosexual history
 Current living
situation
Assessment Procedures
 Mental Status Examination
 Projective tests e.g. Rorschach
 Objective tests e.g. MMPI
 Organic tests e.g. Blood tests, CAT scan
 Collateral information
DSM-IV Classification.
1. Disorders usually first diagnosed in infancy,
childhood or adolescence
2. Delirium, dementia & amnestic, & other cognitive
disorders
3. Mental disorders due to a general medical condition
4. Substance related disorders
5. Schizophrenia & other psychotic disorders
6. Mood disorders
7. Anxiety disorders
DSM-IV Classification.
9. Somatoform disorders
10. Factitious disorders
11. Dissociative disorders
12. Sexual & Gender identity disorders
13. Eating disorders
14. Sleep disorders
15. Impulse control disorders (not elsewhere classified)
16. Adjustment disorders
17. Personality disorders
18. Other conditions that may be a focus of clinical
attention
DSM-IV-TR
The five axes of the DSM-IV-TR
.
• Axis I Clinical syndromes. (All mental disorders & criteria for
rating them except personality disorders/mental retardation,
also abuse/neglect)
• Axis II Personality disorders, Mental handicaps. (Life long
deeply ingrained, inflexible & maladaptive)
• Axis III General medical condition. (Any medical condition that
could effect the patients mental state.)
• Axis IV Psychosocial & environmental problems. (Stressful
events that have occurred within the previous year)
• Axis V Global assessment functioning. (How well the patient
performed during the previous year)
ICD-10
• It was agreed whilst being constructed that because of the
incomplete and often controversial state of knowledge about the
aetiology of most psychiatric disorders, the classification would
be worked out on a descriptive basis.
• Implying that disorders should be grouped according to
similarities and differences of symptoms and signs so that a
particular disorder should occur in only one place.
• However it soon became clear this would not appeal to clinicians
(they like to make aetiology very important!!) This therefore
makes the ICD-10 impure from a taxonomic point of view, but
still more likely to be used by clinicians than the DSM-IV-TR.
The Use of Diagnostic Criteria
• Both systems have introduced explicit operational
criteria for diagnosis. That is:
• For each disorder there is a specified list of
symptoms, all of which must be present, for a
specified period of time, in relation to age and
gender, stipulation as to what other diagnoses
mustn’t be present, and the personal and social
consequences of the disorder.
• The aim is to make diagnosis more reliable and valid
by laying down rules for the inclusion or exclusion of
cases.
Problems with the
Classification of Mental Disorders.
• Diagnosis is the process of identifying a disease and
allocating it to a category on the basis of symptoms
and signs.
• Therefore any system that psychiatrists cannot
agree upon has little value (inter-rater /inter- judge
reliability) and represents a fundamental requirement
of any classification system.
• What are your thoughts?
Example of Diagnosis:
• Patient: Johnnie Walker
– Axis I: Major depressive Disorder
– Axis II: Narcissistic Personality Disorder - some
features only
– Axis III: Poor liver functioning,
frequent migraines.
– Axis IV: Recently retrenched
– Axis V: 65
Problems with DSM Classification.
• Labeling:
Ø Tends to be reductionistic.
Ø May lead to stigmatisation, or person
taking on the sick role and identifying
with the label.
Ø Labels are “sticky” (Rosenhan study).
Ø Instrument of social control: gives mental
health professionals control over
people’s lives.
Alternate Approaches:
Dimensional System
• More holistic: considers a person's functioning on a
number of different dimensions, which would reflect
their strengths and weaknesses.
• Rating on a continuum scale may be able to reflect
the graduations between normality and abnormality.
• Database of profiles may be used to construct a new
classification system.
Problems with the
Classification of Mental Disorders.
• Early studies have shown time after time poor
diagnostic reliability. WHY?
• One reason may lie in the fact that information elicited
in interviews vary widely; the interpretation of the said
information is also largely subjective.
• Secondly, trained psychiatrist from different countries
showed great variation in their interpretations.
• E.g. UK-US Diagnostic Project showed American &
British psychiatrists the same videotaped clinical
interviews and asked them to make a diagnosis. New
York psychiatrists diagnosed schizophrenia twice as
often, while the London psychiatrists diagnosed
mania and depression twice as often.(Cooper et al
1972)
The International Pilot Study
of Schizophrenia (WHO,1973)
• Compared psychiatrists in nine countries
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Columbia
Czechoslovakia
Denmark
England
India
Nigeria
Taiwan
USA
USSR
• There was substantial agreement between 7 of the 9. The
exceptions were USA & USSR which both seemed to have
unusually broad concepts of schizophrenia (thus confirming
Coopers results!)
So… How do we improve reliability?
What if professionals are trained to use the same
standardised interview schedules?
The Function of Classification
• Inform effective treatment selection
• Administrative functions e.g. Medical aids, legal
system.
• Provides vocabulary for professionals to communicate.
Clinical shorthand.
• Provides information on prognosis.
Problems with the
Classification System.
• Co-morbidity: e.g. depression and anxiety, psychotic
disorders and mood disorders. Questionable validity?
• Reification: an alcoholic vs. a person with an alcohol abuse
disorder.
• Discounts graduations between normality and abnormality.
Tends to focus on pathology.
• Descriptive nature of system may hamper theoretical
development and research on etiology.
• Focus on reliability to the detriment of validity
Validity of Diagnostic System
Validity: the degree to which the category reflects the
disorder it seeks to describe.
Construct validity: whether the symptoms chosen as
criteria for a disorder are consistently associated with
the disorder.
Descriptive validity: The extent to which the diagnostic
classification provides significant information about the
individuals placed in the category. Frequent criticism.
Predictive validity: extent to which a diagnosis is able to
predict the course of the disorder and the efficacy of
different types of treatment
Reliability of
Diagnostic Systems:
• Reliability: The extent to which different clinicians
agree in identifying a disorder.
• Validity and reliability are often at odds with each
other. DSM-IV accused of sacrificing validity for
increased reliability.
• Research methods trade off between reliability and
validity when using either lab or field experiments.
Being Sane:
Really, I Am! Or Am I?…
• Rosenhan (1973)
• 8 ‘normal’ people presented themselves at the
admissions office of 12 different psychiatric
hospitals in the USA.
• Hearing voices, etc… all 8 admitted with
schizophrenia/manic depression.
• Eventually discharged with diagnosis of
schizophrenia/manic depression in remission.
• The only people suspicious of them were the patients.
It took between 7 and 52 days for them to convince
staff they were well enough to be discharged.
And there’s more!
• In a second study members of a teaching hospital
were advised about the results of the original study
and warned they would receive pseudo patients trying
to gain entry. Each member of staff were asked to
rate who was genuine and who was the fake.
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193 patients were admitted
41 were confidentially alleged to be impostors
23 were suspected by one psychiatrist
19 were suspected by another psychiatrist and
another member of staff.
And the prize goes to...?
 All were genuine patients!
 What conclusion can be drawn about psychiatric
diagnosis from Rosenhans study?
 Are there features of the study that would make
generalisations difficult?