Classification & Diagnosis Flashcards
Current Classification Systems
- International Classification of Diseases and Health Related Problems (ICD) o World Health Organisation o Mental disorders first added in 1948 o Currently in its 10th edition - Diagnostic and Statistical Manual of Mental Disorders (DSM) o American Psychiatric Association o 1st Edition published in 1952 o Currently in its 5th edition (2013)
Both reflect medical model
The Medical Model
Classification and diagnosis of illnesses is based on illness is qualitatively different from health (different illnesses are clearly distinguishable from each other, occur independently from each other, have specific, identifiable causal agents, respond to specific treatment)
Aetiologically based diagnosis is the ultimate goal of medical (psychiatric) classification
o i.e., aim is to identify diagnostic categories (syndromes) that have their own specific causes, lead to specific treatments → A ‘syndrome’ is only a ‘disease’ once we know its cause (e.g. AIDS)
Early attempts attempts for aetiologically based classification
- Early attempts for aetiologically based classification of various types of ‘insanity’ were based on hypothesised causes and were often wrong o Hippocrates (c.460-377 BCE) → hysteria (‘hustera’ = uterus) o Paracelsus (16th Century) → Vesania, Lunacy, Insanity o Henry Maudsley (1867) → Masturbatory insanity
Emergence of Medical/Biological Model
- P. Broca (1824-1880), C. Wernicke (1848-1905)
o Identified associations between specific syndromes (expressive vs. receptive aphasia) and localised damage to the brain - Eventually, all mental illnesses will be identified and categorised according to their underlying biological causes which would lead to effective treatment or prevention
o Bacterial or viral infections
o Localised brain damage
o Toxins
o Heredity
Why did progress of Medical/Biological model slow down in 20th century?
• Infections: ‘local sepsis’ (Henry Cotton, 1907-1930)
• Hypothesis: Chronic infection releases toxins into the body, reaching the brain and causing insanity
• Treatment: remove infected organ(s)
• Teeth, tonsils, colons, testicles, ovaries, uterus
• Death rates of about 45% (mainly from post-surgery infections)
o Lobotomy
- The biological/medical model could not fulfil its early promise
Psychoanalytic Model
- Sigmund Freud (1856-1939)
- Very influential in psychiatry during 1940-70s
- Revolutionised the concept of mental illnesses
o No clear dividing line between normal and abnormal → ‘pathological’ is extreme manifestation of ‘normal’
o Include conditions other than psychotic states → ‘neuroses’: anxiety, depression, various phobias
o No clear dividing line between different categories of mental disorder (neuroses and psychoses) - Extended client base to those with milder conditions
- Proliferation of mental health professions
o Move from insane asylums to outpatient private practices
Development of DSM
- DSM-I (1952), DSM-II (1968)
o Strongly influenced by psychoanalytic theory - E.g. DSM-1 )1952) Depressive reaction:
o “the anxiety in this reaction is allayed, and hence partially relieved, by depression and self-deprecation. The reaction is precipitated by a current situation, frequently by some loss sustained by the patient, and is often associated with a feeling of guilt for past failures or deeds. The degree of the reaction in such cases is dependent upon the intensity of the patient’s ambivalent feeling toward his loss (love, possession) as well as upon the realistic circumstances of the loss” (DSM-I)
Problems with DSM I and II
- Problematic reliability
o Inter-rater reliability: Can we agree on the diagnosis?
• How much depression/ self-deprecation is needed? How often? What if guilt is not present? What qualifies as a ‘loss’? etc - Problematic validity
o Is this really what ‘depression’ is?
• Based on unproven theories about etiology: Depression as a defence from unacceptable unconscious ambivalent feelings - How to solve this problem?
o Emil Kraepelin (1856-1926) → the father of modern psychiatric classification
DSM-III (1980), DSM-III-R (1987), DSM-IV (1994), DSM-IV-TR (2000), DSM-5 (2013)
- Reflects the medical/biological model
- No theoretical assumptions about causation
- If causation is not known → description of symptoms
o Patient report, direct observation, measurement
o Clear, explicit criteria and decision rules
• Improved reliability
• Validity? - Improvement in reliability (we can all agree)
- Validity? (We can all be wrong)
o Aim: identify independent groups of symptoms (syndromes), each reflecting a specific cause
Problems with DSM-III (1980), DSM-III-R (1987), DSM-IV (1994), DSM-IV-TR (2000), DSM-5 (2013)
- Comorbidity is very common
- Diagnostic instability high
- Lack of treatment specificity
- No DSM mental disorder qualifies as a ‘disease’
Changing classification
- Changes in DSM:
o Hysteria → out
o Homosexuality → out
o Generalised Anxiety Disorder (GAD) → in
o Binge Eating Disorder (BED) → in
o Asperger’s Disorder → in, then out again
o Psychopathy → out, but sneaking back in - ICD and DSM are not the same:
o GAD, BED, Mixed Anxiety-Depression - What about anger?