Chapter 1: Issues in Diagnosis: Conceptual Issues and Controversies

1. Chapter 1: Issues in Diagnosis: Conceptual Issues and Controversies Scott O. Lilienfeld Sarah Francis Smith Ashley L. Watts

2. General Terminological Issues • Classification Versus Diagnosis • Classification: Overarching taxonomy • Diagnosis: Act of placing an individual into a category within a taxonomy • Signs Versus Symptoms • Signs: Observable indicators (e.g., crying) • Symptoms: Subjective indicators (e.g., feelings of guilt in depressed patient) • Syndrome Versus Disorder Versus Disease • Syndrome: Constellations of signs and symptoms that co-occur across individuals • Disorder:Syndromes that cannot be readily explained by other conditions • Disease: Disorders in which pathology and etiology are reasonably well understood

3. Functions of Psychiatric Diagnosis • Diagnosis as communication • Distills information in a shorthand form that aids in other professionals’ understanding of a case • Establishing linkages to other diagnoses • Locates a patient’s problems within the context of more and less related diagnostic categories • Provision of surplus information • Generates predictions about case trajectory, response to treatment, family history, laboratory researchand so on.

4. Misconceptions Regarding Psychiatric Diagnosis • Mental illness is a myth • Mental illness as “acute problems in living” (Szasz, 1960) • Mental disorders cannot be clearly recognized by corresponding lesions in the anatomical structure of the body • Rebuttal: Many medical disorders cannot be traced to lesions and many lesions do not give rise to medical disorders

5. Misconceptions Regarding Psychiatric Diagnosis • 2. Psychiatric diagnosis is merely pigeonholing • Diagnosing people with mental disorders deprives them of uniqueness. • Rebuttal: Diagnosis merely indicates one way in which people are alike.

6. Misconceptions Regarding Psychiatric Diagnosis • 3.Psychiatric diagnoses are unreliable • Rebuttal: There are many kinds of reliability, which are frequently discrepant with each other • Evaluation of reliability hinges on the conceptualization of a disorder (e.g., high test-retest reliability may be expected for chronic disorders) • Interrater reliability for most psychiatric diagnoses is as high as that of other major medical disorders (Lobbestael, Leurgans, & Arntz, 2011; Matarazzzo, 1983)

7. Misconceptions Regarding Psychiatric Diagnosis • 4. Psychiatric diagnoses are invalid • Simply descriptive labels for behavior we do not like • Rebuttal: Many psychiatric diagnoses provide surplus information (e.g., schizophrenia)

8. Misconceptions Regarding Psychiatric Diagnosis • 5. Psychiatric diagnoses stigmatize people, and • often result in self-fulfilling prophecies • Lead to the interpretation of ambiguous behaviors as consistent with the psychiatric diagnosis (e.g., Rosenhan, 1973) • Rebuttal: Incorrect diagnoses may lead to stigma, but correct diagnoses may actually lead to reduced stigma by providing an explanation for otherwise unexplainable behavior (Ruscio, 2004)

9. What Is Mental Disorder? • Statistical Model • Disorder = Statistical Rarity • No guidelines for cutoff between abnormality and normality • Assumes all common conditions are normal (Wakefield, 1992) • Subjective Distress Model • Core feature of mental disorders is psychological pain • In some ego-syntonic conditions, individuals do not see their behavior as problematic (e.g., narcissistic personality disorder). • Biological Model • Disorder defined in terms of biological (or evolutionary) disadvantage to an individual (e.g., increased risk for suicide in depressed patients) (Joiner, 2006). • Some behaviors incur such disadvantage but are not disorders (e.g., military combat). Some disorders do not incur long-term decrease in evolutionary fitness but are disorders (e.g., phobias)

10. What Is Mental Disorder? • Need for Treatment • Disorder is any condition characterized by a need for medical intervention by a health professional (Kraupl Taylor, 1971) • Some conditions require medical intervention but are not disorders (e.g., pregnancy) • Harmful Dysfunction • Disorders are socially devalued (harmful) breakdowns of evolutionarily selected systems (Wakefield, 1992) • Many medical conditions are adaptive defenses (e.g., vomiting in the flu); many psychological conditions are adaptive reactions to threat • Roschian Analysis • Concept of mental disorder is inherently fuzzy • Mental disorders lack defining features and boundaries • Controversies over concept of mental disorder are inevitable and unresolvable

11. Psychiatric Classification From DSM-I to the Present • DSM-I and DSM-II • DSM-I (APA, 1952): First clear attempt at describing major psychiatric diagnoses in one manual • DSM-II (APA, 1968): Similar in scope to DSM-I; greater detail concerning signs and symptoms of disorders • Major criticisms: • Low interrater reliability for many disorders • Influenced heavily by psychoanalytic concepts of disorders • Neglected consideration of contextual factors (e.g., co-occurring medical disorders)

12. Psychiatric Classification From DSM-I to the Present • DSM-III (APA, 1980)and Beyond • Dramatic increase in coverage of disorders and detailed guidelines for making diagnoses • Standardized Diagnostic Criteria • Signs and symptoms of each disorder explicitly delineated • Algorithms and Decision Rules for Diagnoses • Highly structured guidelines for number of symptoms and combinations of symptoms that must be met for a diagnosis • Hierarchical Exclusions Rules • Rules to prevent diagnoses from being made if other diagnoses better account for the clinical picture

13. Psychiatric Classification From DSM-I to the Present • DSM-III (APA, 1980)and Beyond • Multiaxial Approach • Evaluations along series of axes (e.g., Axis I – Major mental disorders, Axis II – Personality disorders) • Forced a holistic approach to diagnoses • Dropped in DSM-5 • Theoretical Agnosticism • Agnostic with respect to etiology of disorders • Permits use of the manual by practitioners of many different theoretical backgrounds

14. Psychiatric Classification From DSM-I to the Present • DSM-III-R and DSM-IV • Retained major features/innovations of DSM-III • Gradual move to a polythetic approach to diagnosis • Led to increased heterogeneity of diagnoses • Relaxation of many hierarchical exclusion rules (Pincus, Tew, & First, 2004) • DSM-IV added appendix for culture-bound syndromes (e.g., koro)

15. Psychiatric Classification From DSM-I to the Present • DSM-5 • Published May 2013 (APA, 2013) • Retained most of major categories of DSM-IV • Dropped multiaxial system • Attempted to decrease proliferation of new diagnoses by necessitating rigorous validity data for new diagnoses • Criticized for lowering diagnostic threshold for several diagnostic categories (Batstra & Frances, 2012) • Criticized for inadequate field trials focusing on clinical feasibility rather than validity of new diagnostic categories (Frances & Widiger, 2012)

16. Criticisms of Current Classification System • Comorbidity • High levels of co-occurrence and covariation among many diagnostic categories • One disorder may lead to others; two disorders may mutually influence each other or be different expressions of the same underlying liability • May result from overlapping diagnostic criteria or clinical selection bias (du Fort, Newman, & Bland, 1993) • Especially problematic for personality disorders (Widiger & Rogers, 1989) • Often underestimated in clinical practice • May be attaching multiple labels to different manifestations of the same condition

17. Criticisms of Current Classification System • Medicalization of Normality • 1. Increased number of diagnoses in DSMs 2. Lowered threshold for diagnoses in DSM-V (e.g., age of onset in ADHD) • May reflect splitting of broad diagnoses into narrower subtypes (Wakefield, 2001) rather than increased coverage • DSM-V also practiced lumping of narrower diagnostic categories into broader ones (e.g., autism spectrum disorder) • Neglect of the Attenuation Paradox (Loevinger, 1957) • Efforts to achieve high reliability (especially internal consistency) may decrease validity of psychiatric diagnoses • Occurs when a narrow pool of items is used to describe a broad, multifaceted construct

18. Criticisms of Current Classification System • Unsupported Retention of a Categorical Model • DSM is exclusively categorical at measurement level- individuals either meet a diagnostic criteria for a disorder or not • Growing evidence that many DSM diagnoses are underpinned by dimensions rather than taxa (Kendell & Jablensky, 2003) • Measuring most disorders dimensionally almost always results in higher correlations with external validating variables (Craighead, Sheets, Craighead, & Madsen, 2011)

19. The DSM : Quo Vadis? • Dimensional Approach • Growing evidence for dimensionality of many psychiatric conditions • Many suggest using sets of dimensions from personality science to aid in psychiatric diagnosis (Krueger et al., 2011; Widiger & Clark, 2000) • Five-Factor Model (FFM; Goldberg, 1993) • Disagreement about nature and number of personality dimensions to be used • Distinction between basic tendencies and characteristic adaptations is often neglected (Harkness & Lilienfeld, 1997) • Personality dimensions may not be sufficient by themselves to capture full variance in psychopathology

20. The DSM : Quo Vadis? • Endophenotypic Markers  • Accumulating research on biochemistry, brain imaging, performance on laboratory tasks and psychopathology • Widespread assumption that endophenotypic markers are more closely related to etiology than exophenotypic markers (Kihlstrom, 2002) • No endophenotypic markers of psychiatric diagnoses to date come close to serving as inclusion criteria for respective disorders • May better serve as exclusion criteria • Research Domain Criteria (RDoC): Proposed alternative to DSM; goal is to identify psychobiological systems that underlie psychopathology (Morris & Cuthbert, 2012) and markers of those systems