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/derealizat ion 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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