Presentation on theme: "Classification of mental disorders.. Classification of mental Disorders. All systems of mental disorders and diagnosis stem from the work of Kraepelin."— Presentation transcript:
Classification of mental Disorders. All systems of mental disorders and diagnosis stem from the work of Kraepelin. He claimed certain groups of symptoms occur together often, 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).
Classification cont.. 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 The International classification Of Diseases (ICD). Published by the World Health Organisation (WHO) His 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) DSM IV (1994): Ø Effort to develop a consistent worldwide system of classification that would be compatible with the ICD- 10. Ø Huge 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 Ø Previous mental illness Medical history Ø Childhood history Ø Occupational functioning Educational history Ø Marital and relationship history Ø Family history Ø Religion Ø Psychosexual history Ø Current living situation
Assessment Procedures Mental Status Examination · Projective tests e.g. Rorschach, TAT. · 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 retardation. (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 disorder. 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 and 2005 Darwin Awards) 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 disorder. 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, also the interpretation of the said information is 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 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? If the professionals are trained to use the same standardised interview schedules E.g. Present State Examination (PSE) Wing et al (1974).
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. NB: Research methods trade off between reliability and validity when using either lab or field experiments.
Being sane in an insane place!!! 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 schiz/Manic d- press 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.
But 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. 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 form Rosenhans study? Are there features of the study that would make generalisations difficult?