Chapter 4 Classification and Diagnosis

•Helps to more clearly define problems

•Provides basis for communication

•Necessary for research and advancing scientific understandings

•First step to deciding on treatment

Classification

DSM classification

•Diagnostic and Statistical Manual (DSM) of the American Psychiatric Association

•First DSM published in 1952

•DSM-III (1980) introduced multi-axial classifications

•DSM-IV (1994) Dr. Allen Frances chaired the working group task force

•DSM-5 (2013) introduces changes including elimination of multi-axial system

DSM-5 Development

Goals for DSM-5:

•Address gaps in diagnoses

•Update criteria based on new research knowledge

•Reduce the number of Not Otherwise Specified (NOS) classifications because too generic

•Add dimensions to categorical system

•Streamline and simplify diagnoses

Overview of DSM-5 changes

1. New disorders (e.g., binge eating disorder)

2. New criteria for some existing disorders

3. Combining some disorders into a single bigger category

4. New conceptualizations for current disorders (e.g., OCD is no longer considered an anxiety disorder)

5. New names for some existing disorders

6. New dimensional ratings within some disorders

7. Suicidal risk now highlighted

8. Reorganization of age-related considerations

DSM-5 Controversies

1.Autism Spectrum Disorder – eliminates previous Asperger’s syndrome diagnosis

2.Disruptive Mood Dysregulation Disorder is criticized as “temper tantrum disorder”

3.Bereavement can no longer exclude Major Depression – may over-diagnose normal grieving

4.Personality disorders still classified as categories not dimensions

5.Some disorders being considered were omitted (non-suicidal self-injury)

DSM-5 Controversies (cont.)

•Dr. Allen Frances argues:

• that DSM-5 changes will lead to dramatic increase in number of people diagnosed with disorders termed diagnostic inflation

• that the pharmaceutical industry will benefit most by developing new drugs for new disorders and new people qualifying for reimbursement since they are now diagnosed

• for a return to a more cautious approach to diagnostic classification

Key Concepts in Classification

•Epidemiology – study of frequency of disorders in populations

•Prevalence – proportion of people who have a diagnosis at any given time

•Lifetime prevalence – proportion who have ever had a diagnosis in their lifetime

•When prevalence rates rise dramatically, there is concern that ‘normal’ individuals are being incorrectly diagnosed

Key concepts in classification (cont.)

•Comorbidity

• defined as the co-occurrence of different disorders

• considered a major issue because it makes treatment planning more difficult

•when there is high co-morbidity it raises concerns that the disorder is not distinct

Overview of DSM-5 Diagnostic Categories

•Neurodevelopmental Disorders• ADHD• Intellectual Disability• Autism Spectrum Disorders• Communication Disorders

•Neurocognitive Disorders•Substance-Related and Addictive

Disorders• Substance-related disorder• Gambling disorder

•Schizophrenia Spectrum and Other Psychotic Disorders

•Depressive Disorders• Major depressive disorder• Mania • Bipolar disorder • Premenstrual dysphoric disorder

•Anxiety Disorders• Specific Phobia • Panic disorder• Generalized

anxiety disorder• Separation

anxiety disorder

•Obsessive Compulsive and Related Disorders• Obsessive-

compulsive disorder

• Body dysmorphic disorder

• Trichotillomania• Hoarding Disorder

Overview of DSM-5 Diagnostic Categories (cont.)

•Somatic Symptom and Related Disorders• Somatic symptom

disorder • Conversion disorder • Illness Anxiety Disorder

•Dissociative Disorders• Dissociative amnesia • Dissociative identity

disorder • Depersonalization/

derealization disorder

•Sexual Dysfunctions•Paraphilic Disorders •Sleep-Wake Disorders

• Insomnia and Dyssomnia• Parasomnias

•Feeding and Eating Disorders• Anorexia nervosa• Bulimia nervosa• Binge eating disorder

•Trauma and Trauma related Disorders• PTSD• Acute stress disorder• Adjustment disorders

•Disruptive, Impulse-Control and Conduct Disorders• Intermittent explosive

disorder• Kleptomania• Pyromania• Oppositional Defiant

Disorder• Conduct Disorder

Overview of DSM-5 Diagnostic Categories (cont.)

•Personality Disorders• Schizoid personality disorder• Narcissistic personality disorder • Anti-social personality disorder, etc.

•Personality Disorders were previously categorized on Axis II (DSM-IV-TR)

Criticisms of Classification

• General Criticisms• Loss of information about

person• Stigmatizing

• Specific Criticisms• Discrete Entity vs. Continuum• Dimensional Classification vs.

Categorical Classification

• DSM represents a categorical classification• Yes–No approach to

classification• Continuity between normal

and abnormal behaviour not taken into consideration

Advantages of categorical versus dimensional classification

Categorical

• if need to know if person either has does not have disorder

• if need to know whether to start or not start certain treatment

Dimensional

•most helpful when the disorder has levels (from mild to severe)

• tends to have less comorbidity since measures are on a continuum, not all or none

Reliability

•Reliability is the cornerstone of any diagnostic system

•Measures consistency• Inter-rater reliability

Components of reliability

•Sensitivity•Extent to which there is agreement that the

diagnosis is detected as being present

•Specificity•Extent to which there is agreement that the

diagnosis is absent

•Kappa•Statistic used to measure extent of agreement

over and above chance levels

Improvements in Reliability

•Early editions of the DSM (prior to DSM-III) • were unreliable • many diagnostic

disagreements• Information

provided to make diagnoses depended on what an individual clinician might choose to ask about

•Newer editions of DSM • more extensive

descriptions• more precise

diagnostic criteria• increased use of

standardized diagnostic interviews has improved reliability by providing same detailed information

Validity

•Construct validity is most important for diagnosis• How well does the diagnosis relate to other aspects

of the disorder?

Culture and Diagnosis•Early editions of DSM were criticized for

lack of consideration of culture and ethnicity

•DSM-IV-TR introduced culture-bound syndromes:• amok – dissociative episode involving a

period of brooding followed by violent outburst

•DSM-5 elaborated four specific themes to be considered in making cultural formulation:• Cultural identity• Cultural consideration of distress• Cultural features of vulnerability and

resilience• Cultural features of the relationship between

clinician and patient

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