Chapter 7 (Lecture) Flashcards
what is nosology?
The study of how medicine classifies illnesses
Nosology classification methods
- one method of classification is by cause - often used for physical/medical illnesses, but difficult to use in mental health (due to lack of biomarkers)
- DSM concentrates on symptoms and clusters of symptoms (rather atypical in medicine)
- mental disorders are classified according to symptoms (the patterns of thoughts, moods, and behaviours) that people exhibit
- this is a descriptive or symptom-based approach: key assumption is that symptom typical of a particular disorder stem from the same underlying condition (or disorder) - this has been the approach since the DSM-III (1980)
Symptom-based classification
two key issues that represent a challenge to this approach to classification include:
1. symptom overlap
2. heterogeneity
What is Symptom Overlap?
some symptoms (like anhedonia) are common to many mental illness (like schizophrenia, MDD) - some are especially common (anxiety/tension)
What is heterogeneity?
Individuals with the same diagnosis may display very different symptoms and present differently (wide variety of symptoms for each disorder)
- DSM criteria usually require only some of the noted criteria (MDD diagnosis based on 5/9 potential markers)
Implications of symptom-based classification
- symptom overlap - poses a challenge in discerning the dividing lines between different mental disorders (are the distinctions accurate or meaningful?)
- may cause us to question definitions and distinctions between disorders - heterogeneity - diversity of presentations/behaviours/symptoms makes it difficult to explain behaviours and determine the best treatments
- Diagnoses are short-hand (like a label) and sometimes approximate: given range of symptoms and variation, are these two cases or individuals experiencing the same disorder?
OCD and PTSD are both similar and different
- distinct disorders, separate chapters in the DSM-5, different core symptoms that differ meaningfully
- some underlying similarities (anxiety, worry, fear)
- described by same DSM-5 committee, which also was responsible for anxiety
What is OCD?
OCD can be described as a manifestation of anxiety revolving around obsessive and intrusive thoughts
- widely misunderstood, partially due to media depictions
Two primary components:
1. Obsessions: disruptive, anxiety producing thoughts and/or mental images - uncontrollable thoughts - common themes related to contamination, sex, religion, precision violence, harm
2. Compulsions: repetitive actions or thoughts which are performed in order to help relieve anxieties stemming from obsessions - these could be repetitive cleaning, counting, checking on things
- when severe, can prevent individuals from completing normal routines, and can result in serious impairment
OCD prevalence and tendencies
- estimated to affect 1-3% of US population
- OCD often thought as chronic (or persistent) - lasting throughout a person’s lifetime, rather than being episodic
- people with OCD may avoid people, places, things that trigger obsessive thoughts (avoidance is part of the disorder, similar to anxiety)
What is PTSD?
Similar to OCD due to the intense sensations of anxiety and tension (but not the same at all)
- typically arises following a single traumatic event or repeated trauma over a period of weeks, months, or years (diverse route to emergence)
- these events involve experiencing or witnessing severe harm, injury, danger, or death
- symptoms brought on by trauma, including second-hand experience of trauma (a loved one experiencing trauma)
- we are familiar with combat-related PTSD, but accidents, abuse, and violent crime can also trigger PTSD (a wider range of experiences are now understood to be traumatic)
PTSD Symptoms
- “dissociative” episodes (flashbacks, nightmares) associated with triggers
- nightmares
- negative moods
- sleep disruption
- constantly feeling tense
Reliving trauma is a key component, which may bring on or intensify symptoms
Similarities between OCD and PTSD
- anxiety (symptoms of worry or fear)
- attempts to avoid triggers (avoidance)
- OCD may also manifest following experiences of trauma (or may emerge independently)
- similar treatments for both: psychotherapy (CBT) and exposure-based therapies
- both are similar to anxiety, and were previously grouped within anxiety disorders in earlier DSM editions
Differences between OCD and PTSD
- core features are distinct: obsessions and compulsions are very different experiences than “flashbacks”
- OCD is not always triggered by a traumatic incident
Somatic symptom and related disorders
- These two disorders involve concerns about one’s health, substantial anxiety, excessive worry, rumination (repetitive thinking or dwelling on negative feelings and distress) and avoidance
Somatic Symptom Disorder: describes individuals who have anxiety and/or a fixation on somatic symptoms such as headache and pain - was previously “conversion disorder” (distress or internal conflict “converted” into physical dysfunction) before that “hysteria”
- people may or may not have a diagnosis for a physical illness that is causing their symptoms
- the diagnosis of this disorder is related to an “excessive and abnormal” psychological reaction to the physical symptoms
Illness Anxiety Disorder: this disorder is characterised by excessive worry about the possibility of becoming ill, previously known as hypochondriasis - “easily alarmed about personal health status” may perform excessive health-related behaviours (checking for signs of illness)
- may extensively use health system, but concerns are rarely alleviated through care/visits, often feel medical assessments has been inadequate
- may be extra-sensitive to bodily sensations, including more likely to report side effects of medications
Both of these disorders demonstrate that there is a complex link between physical and mental health, and raise some interesting questions:
1. Who determines when health concerns are “excessive”?
Traditionally it is a clinical, but what about the patient perspective?
2. Might these diagnoses pathologies people who have medically unexplained illnesses?
Perhaps there is a real medical condition at the root of the symptoms but it is not yet discovered or known
Clinical Perspectives (positivist and constructivist)
Study of assumptions about knowledge are often based on two broad frameworks:
- Positivist Framework: sees scientific knowledge as always improving, assumes that we can acquire concrete knowledge about a topic using technology and reason (THERE IS AN OBJECTIVE TRUTH)
- Constructivist Perspective: sees knowledge as fluid and contextual. Our understanding of a phenomena is influenced by our social position and experiences. Our decisions about what to study and how we think about it are influenced by culture, politics, scientific trends, and other factors (“TRUTH” IS SUBJECTIVE, AND DEPENDENT UPON SOCIAL CONTEXT AND EXPERIENCE, AND WILL EVOLVE/CHANGE)
Epistemology
The study or a theory of the nature and grounds of knowledge especially with reference to its limits and validity
- ways of looking at or knowing the world
- what counts as valid knowledge, as “truth”
- rules for knowing things about the world
Positivism
- strongly associated with natural sciences (think physics)
- one reality/truth exists (there is an objective external reality)
- reality can be measured objectively and accurately
- concerned with verifiable observation and measurement, prediction and control
- assumptions reduce complexity and context - tends to fragment human experiences
Positivism –> Post-positivism
- increased acknowledgement of (and ability to deal with) complexity/context
- increased recognition of social construction and subjectivity
- increased opposition to positivism and critiques from: feminist research, social justice research, indigenous ways of knowing and knowledge/perspectives
Post-Positivism
- all observations is fallible and has error
- all theory is revisable
- still a goal to capture reality/truth but recognition that we can never really get there
- all scientists are biased but through transparency can approach the goal of objectivity
