A diagnosis is an identification of a condition or disease state
This is a medical notion that may or may not apply to psychological problems
Need a diagnostic system-- a collection of rules for guiding us in our determination of a diagnosis
What does it mean to "diagnose"?
A "cold" is different from pneumonia in that…
Depression is different from anxiety
[In psychiatry, a diagnosis is solely descriptive]
Need descriptors that allow different clinicians to recognize the same disorder (reliability)
Need descriptors such that if present, they indicate the presence of a disorder, and if absent, the disorder is absent (validity)
What do we want in a diagnostic system?
Is it enough for someone to say "I am depressed?"
Does the person have to cry a lot or talk of suicide?
[Not all depressed people present with the same symptoms, there isn't one symptom that is necessary or sufficient]
Is loss of appetite a symptom, or poor sleep?
How do you know if someone is depressed?
To answer such questions, someone must first define what depression is
Hippocrates: beginnings of a diagnostic system
First comprehensive diagnostic system based on which characteristics occur together
Extended "International List of the Causes of Death" to include psychological abnormalities
The list was renamed the International Statistical Classification of Diseases, Injuries, and Causes of Death (ICD)
1948: World Health Organization
Heavily psychoanalytic-- manuals focused on unobservable internal states
Not based in empirical research
Did not involve objective criteria
Diagnostic categories were:
Consequently, it was not very useful, and different clinicians would come up with different diagnoses for the same person
1952-- American Psychiatric Association published its own diagnostic system, the Diagnostic and Statistical Manual of Mental Disorders (DSM)
Suffered from many of the same problems as the original DSM
Multi-axial classification-- rather than using a single label, client described in terms of a number of clinically important factors, or axes
Focus on descriptive features that allow identification of the problem rather than interpretation based on unvalidated theories
Provided detailed criterion sets for each disorder, to allow various clinicians to diagnose in a similar way
Attempted to be atheoretical; eliminated theory-laden terms such as "neurosis" (psychoanalytic)
Radically different from DSM-II
1987: DSM-III-R-- a minor revision
Evaluated more than 6000 subjects, using hundreds of clinicians, looking at reliability and validity
Development team searched for an empirical basis for each disorder, and carried out extensive field trials using the classification system
Developers took more international approach; Cooperated with the developers of ICD-10 which is widely used around the world outside of North America
1994: DSM-IV-- major revision, still using the multiaxial approach
Translated into French as well
2000: DSM-IV-TR-- relatively minor changes to text
Quite different from diagnosis in physical medicine
In physical medicine, data not available from the patient is gathered by tests-- blood tests, x-rays, etc.
Medical diagnoses adds new information about the disorder-- causation, course, treatment, etc.
[Psychological tests are descriptive and do not add new information, this is a huge misconception in psychology]
For both the DSM and ICD (which will be discussed later), diagnoses are defined purely in terms of symptoms
Yet, DSM provides some consistency so that when terms such as depression or anxiety are used, people are describing more or less the same problems
Excluding simple deviance from societal norms
Excluding expected or culturally sanctioned responses-- as to the death of a loved one
"A clinically significant behavioral or psychological syndrome or pattern that occurs in an individual and that is associated with present distress (e.g., a painful symptom) or
disability (e.g., impairment in one or more important areas of functioning) or with a significantly increased risk of suffering death, pain, disability or an important loss of
freedom." (DSM-IV p. xxi)
In DSM-IV, each mental disorder is conceptualized as:
Because of the continuum between normal and abnormal functioning, often only need to fill a subset of conditions to warrant the diagnosis
Aim is to describe accurately the various disorders rather than interpret them
In DSM-IV, NOT assumed that all categories are mutually exclusive, that there is no overlap
Disorders usually first diagnoses in infancy, childhood, and adolescence
Delirium, dementia, amnesic, and other cognitive disorders
Axis I-- Clinical Syndromes
3. Diagnosis & Classification