: an arrangement into groups according to some systematic division
diagnosis
: to determine the cause and nature of a pathological condition; to recognize a disease
boils down to medical classification
why classify?
communication: so physicians can talk about patients
comprehension: info = power; if we can classify something, we feel that we understand it better
control
: helps to predict prognosis and enables us to tell the patient what to expect (most important)
validity
: extent to which a diagnostic category fits or describes the actual disease (accuracy of diagnosis)
reliability
: reproducibility (precision of diagnosis)
Hierarchy of medical conditions
symptoms/signs
: most basic; describe perceptible changes in the body or its functions
syndrome
: a ‘running together of symptoms and signs; what causes a syndrome Þ we don’t know (see disease)
disorder
: clinically significant syndrome or pattern that occurs in a person and results in distress or dysfunction/disability
disease
: requires two of these three: (1) etiology; (2) pathology; (3) course
illness
: the psychological and social experience of having a disease
Example
: hemoptysis, weight loss, and coughing are symptoms and signs
when taken together, they make up the syndrome of consumption
when the etiology and pathophysiology are known, it can be called the disease TB
the experiences of a person with TB (feeling shitty, lost work, etc) is called the illness
since we don’t know the etiology or path of psychiatric conditions, they are classed as disorders, rather than diseases
furthermore, classification is clinical, no pathological confirmation currently exists for psychiatric disorders
DSM IV
- Diagnostic and Statistical Manual of Mental Disorders, Version IV
History
: DSM I was developed in 1954 and has had minor revisions since; DSM IV was issued in 1994
Concepts
mental disorder
: ‘behavioral or psychological syndrome or pattern in an individual resulting in distress or dysfunction
group phenomena (i.e. family issues) are excluded
patient may not be in distress and still be dysfunctional (i.e. they deny their condition)
mental disorders are not necessarily discontinuous; many people have anxiety to a variable degree, but when you pass a certain point on the continuum, it becomes an anxiety disorder
DSM IV is descriptive and atheoretical - it can describe a syndrome, but has no basis in etiology, path, etc.
reliability is high, validity is probably moderate, but is unknown because there is no gold standard to measure against
Major Characteristics
inclusion and exclusion criteria are presented for each disorder
diagnosis is multiaxial
Axis I: Clinical Syndromes - more episodic, can come and go (but not necessarily)
Axis II: Developmental Disorders and Personality Disorders - considered a more permanent part of the patient
i.e. mental retardation
Axis III: Physical Disorders and Condition - lists general medical conditions
Axis IV: Severity of Psychological Stressors - notes other problems which may affect the disorder
i.e. work problems, poverty, etc
Axis V: Global Assessment of Functioning - notes how well the patient has done over time
multiple diagnoses for a single individual are possible
Criticisms of the DSM IV
parochial, reductionistic, confuses state and trait; adynamic; sacrifices validity for reliability; cross-sectional rather than longitudinal