Chapter 3: Classification and Diagnosis Flashcards
Classification Validity
the extent to which the principles used in classifying an entity are effective in capturing the nature of the entity
Classification Ultility
the usefulness of a classification scheme
Categorical Approach to Classification
an entity is determined to be either a member of a category or not
Dimension Approach to Classification
classified entities differ in the extent to which they possess certain characteristics or properties
Diagnostic System
a classification based on rules used to organize and understand diseases and disorders
Diagnosis
the result of applying the decision-making rules of a diagnostic system to the symptoms of a specific individual
Prototype Model
members of a diagnostic category may differ in the degree to which they represent the concepts underlying the category
Developmental Psychopathology
a framework for understanding problem behavior in relation to the milestones that are specific to each stage of a person’s devlopment
Harmful Dysfunction
the behaviors associated with a mental disorder are dysfunctional, and the dysfunction causes harm to the individual or to those around them
Dyscontrol
the impairment resulting from a disorder must be involuntary or not readily controlled
Comorbidity
when a person receives diagnoses for two or more disorders at the same point in time
Why do we classify and diagnose?
concise description
common language used by trained professionals
may contain information about etiology, comorbidity, and prognosis
for searching for treatment
important for theoretical development
guides assessment practices
knowing something about a given clinical/patient type informs the psychologist about relevant areas of inquiry
guides treatment practices
sometimes required to establish funding/program eligibility
Is there a downside to classifying and diagnosis?
important individual differences may be obscured
knowledge base concerning group or type may be irrelevant to the patient in question
may preempt more meaningful diagnostic exploration
categorization (“labeling”) is often seen as pejorative; especially true in a psycholegal context
What is validity in a classification system?
how well a system reflects the true nature of people, disorders, or other things being classified
What is utility in a classification system?
how useful a classification system is in understanding those things, and in advancement of science
What kind of classification is prominent in psychology?
the roots of psychology are in the social sciences, testing, and measurement; this has led to preference for dimensional approaches to classification
based on the assumption that groups and individuals are separated as a matter of degree, or quantitatively, from one another (e.g., heigh, intellectual ability, years of experience, introversion vs. extroversion)
dimensions can be rearranged into categories by setting dividing points
What kind of classification is prominent in psychiatry?
psychiatry, with its roots in the biological sciences, has tended to adopt categorical approaches to classification
based on the view that categories are separated largely by qualitative differences (e.g., male versus female)
What is a prototype model to classification?
for some conditions, e.g. psychpathy, a prototype model has more recently been employed
in many respects a combination of categorical and dimensional approaches
defines a perfect member of a given population and classifies others according to their degree of correspondence to that individual
What are empirically-derived classification systems?
there are statistical procedures, primarily factor analysis and cluster analysis, which allow us to analyze data from groups of people that allow natural categories, groups, or factors to emerge
these may give important clues concerning underlying dimensions
How is diagnosis different from classification?
diagnosis is a special case of classification applied to disorders and those who exhibit them
a diagnostic system can be based either on a dimensional or categorical model
it is always a system of rules used to organize signs, symptoms, and disorders
What are signs?
indicators of illness observable by another individual, and often the person themself
What are symptoms?
indicators of illness observable only to the individual experiencing them
What are the ways of defining abnormality and mental illness?
departure from social norms
functional maladjustment
subjective distress
correspondence to an ideal/cultural hero
the presence of unusual signs/symptoms
the absence of requisite attributes or abilities
What are the three things should a definition of a mental disorder encompass?
that the signs/symptoms are unusual
that they are potentially harmful
that they are non-deliberate (dyscontrol)
Why do most individuals seek services of psychologists and diagnosis?
many individuals seek the services of psychologists with the express purpose of knowing whether they are “sick” or “crazy”
may be reasonable to offer an opinion as to whether certain thoughts, feelings, or behaviors fall within a “normal” range in a given context, but it’s not responsible to offer an opinion about one’s overall mental health in the absence of a proper assessment
one should also have an appreciation of the client’s motivation for asking that question
often simple reassurance and education is adequate
Why is developmental psychopathology important to diagnosis?
one of the key dimensions to be considered is life stage
for example, our behavioral expectations of an infant are markedly different than those of a toddler, adolescent, young adult, middle-aged adult, and senior
possible signs and symptoms of mental illness at one point could be perfectly normal at another
likewise, the supports, interventions, and general treatment of an individual are life stage dependent
vulnerabilities to environmental stressors such as abuse, that lack, and stress vary with developmental stage
What is diagnosis?
interestingly, diagnosis is not a protected (“dangerous”) activity under HPA; this may be because greater potential to do harm is thought to rest with intervention
the process of diagnosis must be scientifically-based; it should never rest on value judgements, the subjective experience of the psychologist, or idiosyncratic theories
in practice, patients, care givers, and third-party referral sources frequently offer their own opinions, even expressing indignation when they are not adopted by professionals
What is the prevalence of mental disorders?
Statistics Canada (2003): one out of every 10 Canadians (adolescent and older) report symptoms consistent with a disorder such as substance abuse, mood disturbance, or anxiety
What were the conclusions of the WHO (2004) data?
WHO (2004) data compared the prevalence of various mental disorders by country
there is significant variability within all classes of mental disorder from one country to another
anxiety and mood disorders appear to be the most prevalent in all areas
regrettably, major mental illness such as schizophrenia appears not to have been considered
mental disorders were viewed as being more disabling than physical disorders, including chronic pain, heart disease, cancer, and diabetes
What is the treatment of mental disorders compared to physical disorders?
mental disorders, low income: 8%
mental disorders, high income: 24%
physical disorders, low income: 53%
physical disorders, high income: 65%
What is etiology?
manifestation of mental disorders depends on the confluence of biological (often genetic), individual, and social factors
how these factors combine varies across disorders, individuals, circumstances, and time
What is resilience?
one’s ability to cope with adverse events
includes traits inherent to that individual, as well as the availability and tendency to make use of external supports including professional services
What is the stress-diathesis model?
the likelihood of developing a mental disorder is a product of vulnerability and adversity
numerous individuals who seek professional services for mood and anxiety issues report experiencing an abundance of traumatic events
conversely, the majority of victims of large-scale natural disasters will not be diagnosable as suffering from a mental disorder, even though they may experience significant grief
What is a longitudinal study?
follow cohorts of individuals over time
What are the prevalence rates of depression at different stages of life?
significant increase in symptoms between grades six and seven
fairly consistent before and after that interval
more pronounced for girls than boys
What are recovery rates?
Eaton et al. (2008) studied changes in depressive symptoms (n = 3500 US adults)
followed up 23 years
about 50% had further occurrences
15% had not had a single year of normal mood following first episode
What is the DSM?
originally published in 1952
strong psychodynamic influence
now up to DSM-V-TR, published 2022
became explicitly atheoretical with DSM-III (1980)
added multiaxial diagnosis
large scale field trials
What is a multiaxial diagnosis?
requires consideration of an individual’s psychological functioning in the context of their physical well-being, psychosocial stressors, and overall (global) level of functioning
oddly, this was removed in DSM-5
What are the complaints about the DSM-5?
lack of openness: confidentiality agreement with the researchers who developed it
over-representation of biological views
70% of task force members with links to pharmaceutical companies
poor reliability of diagnoses and concerns about validity
drew reactions from APA members
In what way is the DSM a categorical system?
dimensional constructs, such as intelligence, are divided into categories
categorical systems do not preclude the possibility of diagnostic overlap, nor membership in multiple groups
can contribute to diagnostic unreliability: discrepancy between UK and US with diagnosing schizophrenia
ca organize disorders according to symptom similarity
How does a diagnostic system interact with research?
a central advantage of any diagnostic system is the potential for facilitating research
grouping individuals on the basis of an agreed-upon system improves the comparability of research findings
fosters development of evidence-based practice
What is a monothetic diagnostic definition?
clinical presentation of a given disorder is highly homogenous, and individuals receiving that diagnosis meet the same criteria
everyone in the group looks the same
What is a polythetic diagnostic defintion?
there are multiple diagnostic criteria ascribing to a given disorder, and there are various constellations of those criteria that can qualify an individual for diagnosis within that category
have core features in common, but can look different
Why is culture relevant to the DSM?
cultural relevance must be carefully considered when making a diagnosis
DSM-IV was the first to provide good information to enhance this area
there are a number of “disorders” that are diagnosed in some cultures but relatively unheard of in others
cultural sensitivity is therefore not just a matter of political correctness
How do comorbid conditions impact diagnosis?
the prevalence of comorbid conditions must also be recognized in order to facilitate adequate planning for the management of more complex presentations
it is sometimes difficult to know whether comorbid symptoms truly represent the presence of a seperate disorder, or simply a subtype of the central disorder
eg., FASD, RAD, ADHD
exacerbated by the use of specifiers
In what way does the DSM not distinguish between normal and serious pathology?
e.g., are depressive symptoms normal reactions to an acute stressor, or do they herald the onset of a true mood disorder?
sometimes thus can only be answered with time; this criticism is not unique to mental disorders, nor the DSM
What are the disadvantages of the DSM?
doesn’t always adequately distinguish between normal reactions and more serious pathology
may be overly sensitive and insufficiently specific
diagnostic reliability is suboptimal
What is sensitivity in a diagnostic system?
reflects an instruments ability to avoid false negatives
usefulness and how good it is at picking up the disorder
What is specificity in a diagnostic system?
reflects that instrument’s ability to avoid false positives
picking up what you’re looking for and nothing else
In what ways is the diagnostic reliability of the DSM suboptimal?
significant gains over previous versions of DSM
can be formally evaluated by calculating interrater reliability
results tend to be best across broad categories, but lower with higher levels of specificity; indeed, these are often below acceptable levels
to the extent that categorical systems artificially dichotomize certain attributes, this was a predictable problem
exacerbated by polythetic diagnostic defintions
What is the ICD-11?
International Statistical Classification of Diseases and related Health Problems
published by WHO (2019)
covers all health conditions, including mental and behavioral disorders
42 languages (vs English only in DSM)
available free online (vs DSM: major revenue for APA)
diagnostic criteria only
used to assess prevalence
