CH15 – Psychological Disorder

The below information is derived from the textbook “Psychology Themes & Variations”.

Resources

Podcast	Part 1 Part 2 Notes Specific Schizophrenia
Matching Quiz	Disorders Disorder Timing Diagnosis Criteria Notes Schizophrenia Personality Disorders
Multiple Choice Quiz	Part 1 Part 2 Part 3 Part 4 Notes Quiz

The Breakdown

Here is a summary of the provided sources, structured according to your specified sections:

Overlaps

Medical Model of Abnormal Behaviour – The medical model proposes that it is useful to think of abnormal behaviour as a disease. This model continues to dominate thinking about psychological disorders. Medically based concepts such as diagnosis, which involves distinguishing one illness from another, etiology, which refers to the apparent causation and developmental history of an illness, and prognosis, a forecast about the probable course of an illness, have proven valuable in the treatment and study of abnormality. Thomas Szasz likened the concept of a “sick mind” to a “sick joke” or “sick” economy, questioning the strict medicalization of mental illness. However, the medical model’s terms are widely understood among professionals.
DSM-5 – The DSM-5 is the formal classification system used in the diagnosis of psychological disorders in North America. It was released in 2013. The DSM-5 uses the term DSM-5 instead of DSM-V to facilitate incremental updates. One major issue in its development was the system’s commitment to a categorical approach, where people are placed in discontinuous diagnostic categories. Critics note the enormous overlap among various disorders’ symptoms. The number of specific diagnoses in the DSM has more than quadrupled since the first edition. Critics worry that the expansion of diagnoses could lead to the medicalization of everyday problems.
ICD-11 – One major alternative to the DSM developed by the World Health Organization (WHO) is the International Classification of Disease and Health Related Problems (11th edition) (ICD-11). It was officially endorsed by the WHO in 2019. You are more likely to encounter the ICD-11 in Europe than in North America, where the DSM-5 is primary. The ICD-11 is a broad system including physical and mental disorders. While there is substantial overlap, there are also differences; for example, the ICD-11 includes complex PTSD as a distinct category, unlike the DSM-5.
Research Domain Criteria Project (RDoC) – The National Institute of Mental Health (NIMH) has developed the Research Domain Criteria Project (RDoC). According to the NIMH, this system is being developed primarily for research purposes. It is based on dimensions of observable behaviour and neurobiological measures. The intent is to base this system more directly on research findings, considering basic psychological and neuropsychological processes.
Epidemiology and Prevalence – Epidemiology is the study of the distribution of mental or physical disorders in a population. Estimates of the prevalence of psychological disorders can vary depending on the sampling methods and assessment techniques used. The most recent large-scale epidemiological study estimated the lifetime risk of a psychiatric disorder to be 44 percent in the United States. In Canada, by the time individuals reach 40 years of age, approximately one half will have or have had a mental illness. According to data from Statistics Canada (2013), common types of psychological disorders in Canada include anxiety disorders, mood disorders, and substance use disorders. A significant percentage of Canadians who report symptoms consistent with psychological disorders do not seek assistance.
Stigma and Misconceptions – Misconceptions about abnormal behaviour are common. The stigma associated with psychological disorders prevents care seeking. Stereotypes include the belief that psychological disorders are incurable, that people with them are often violent and dangerous, and that they behave in bizarre ways and are very different from normal people. Reality shows that the vast majority of people diagnosed with mental illness eventually improve, only a modest association has been found between mental illness and violence-prone tendencies, and bizarre behaviour is seen only in a small minority of cases with severe disorders.
Rosenhan Study – The study by Rosenhan involved pseudopatients who feigned hearing voices to gain admission to psychiatric hospitals. Except for this symptom, they acted normally and gave accurate personal histories. All were admitted, and the average length of their hospitalization was 19 days. This study evoked controversy about the diagnostic system for mental illness.
Generalized Anxiety Disorder – Generalized anxiety disorder is characterised by a persistent feeling of anxiety not tied to a specific object or situation. It tends to have a gradual onset and is seen more frequently in females.
Panic Disorder – Panic disorder is marked by recurrent attacks of overwhelming anxiety.
Agoraphobia – Agoraphobia is often described as a fear of situations where escape might be difficult or help wouldn’t be available.
Obsessive-Compulsive Disorder (OCD) – In the DSM-5, obsessive-compulsive disorder (OCD) is now classified under a new class of disorders called obsessive-compulsive and related disorders. This class includes conditions linked by excessive preoccupation and/or repetitive behaviours, such as hoarding disorder and body dysmorphic disorder. Obsessions are thoughts that repeatedly intrude on one’s consciousness in a distressing way, while compulsions are actions that one feels forced to carry out. Common compulsions include constant hand-washing and repetitive checking of locks. Research suggests that OCD may be a heterogeneous disorder with multiple underlying factors, with symptom dimensions like obsessions and checking, symmetry and order, cleanliness and washing, and hoarding.
Hoarding Disorder – A newly introduced disorder in the DSM-5 is hoarding disorder. It is characterised by a persistent difficulty discarding or parting with possessions, regardless of their actual value, due to a perceived need to save items and distress associated with discarding them, resulting in clutter that compromises living areas.
Post-Traumatic Stress Disorder (PTSD) – Post-traumatic stress disorder (PTSD) can be triggered by a major traumatic event. It is part of a new class in DSM-5, trauma- and stressor-related disorders. Symptoms of PTSD include re-experiencing the traumatic event in the form of nightmares and flashbacks, emotional numbing, alienation, problems in social relationships, an increased sense of vulnerability, and elevated levels of arousal, anxiety, anger, and guilt. The ICD-11 distinguishes between PTSD and complex PTSD (CPTSD), which includes PTSD symptoms along with additional symptoms of affect dysregulation and difficulties in relationships.
Etiology of Anxiety Disorders – Twin studies suggest a moderate genetic predisposition to anxiety disorders. Neurochemical activity in the brain, particularly disturbances in neural circuits releasing GABA and abnormalities at serotonin synapses, may contribute. Classical conditioning and observational learning can lead to the acquisition of anxiety responses, while operant reinforcement can maintain phobic responses. Cognitive theorists believe individuals vulnerable to anxiety disorders tend to misinterpret harmless situations as threatening, focus excessive attention on perceived threats, and selectively recall threatening information. High stress may help precipitate the onset of anxiety disorders. Some fears may be more easily acquired due to evolutionary history, a concept updated by Ohman and Mineka (2001) as an evolved module for fear learning, suggesting a preparedness or biological bias towards ancient sources of threat.
Dissociative Amnesia – Dissociative amnesia is characterised by an inability to recall important autobiographical information, typically of a traumatic or stressful nature. The memory gaps exceed normal forgetting and are not due to other medical conditions. Canadian research suggests prevalence rates of approximately 1-3% in the general population. It typically develops as a psychological response to trauma or stress.
Dissociative Identity Disorder (DID) – Dissociative identity disorder (DID) involves the co-existence of two or more largely complete and usually very different personalities or experiences of possession. It involves recurrent gaps in the recall of everyday events and personal information and is associated with overwhelming experiences and childhood trauma. Some skeptical theorists believe the increased prevalence may be partly attributed to book and movie portrayals and reinforcement from therapists.
Mood Disorders – Mood disorders are marked by emotional disturbances of varied kinds. The DSM-5 has separate classes for bipolar and related disorders and depressive disorders.
Major Depressive Disorder – A key symptom of major depressive disorder is often anhedonia—a diminished ability to experience pleasure. People show persistent feelings of sadness and despair and a loss of interest.
Bipolar Disorder – Bipolar disorder is characterised by the experience of both manic and depressive episodes. During a manic episode, a person’s mood typically becomes elevated to the point of euphoria.
Specifiers for Mood Disorders – Two well-known specifiers for mood disorders are seasonal affective disorder (SAD) and postpartum depression. Postpartum depression sometimes occurs after childbirth, within four weeks.
Suicide and Mood Disorders – A tragic problem associated with mood disorders is suicide. About 90 percent of people who complete suicide suffer from some type of psychological disorder.
Etiology of Depressive and Bipolar Disorders – Twin studies have found a significantly higher concordance rate for mood disorders in identical twins compared to fraternal twins, suggesting a genetic predisposition. Low levels of serotonin appear to be a crucial factor underlying most forms of depression, and disturbances in neural circuits using serotonin and norepinephrine contribute. Research has found an association between depression and reduced volume in the hippocampus, possibly reflecting suppressed neurogenesis due to stress. High stress is associated with increased vulnerability to both depression and bipolar disorder.
Cognitive Theories of Depression – Seligman (1974) proposed that depression is caused by learned helplessness—passive “giving up” behaviour produced by exposure to unavoidable aversive events. Alloy and colleagues (1999) found that a negative explanatory style in college students predicted vulnerability to depression. Cognitive theorists assert that people who exhibit a pessimistic explanatory style are especially vulnerable.
Behavioural Approaches to Depression – Behavioural approaches to understanding depression emphasise the role of inadequate social skills.
Schizophrenia – Literally, schizophrenia means “split mind,” referring to the fragmentation of thought processes, not “split personality” (which is dissociative identity disorder). Prevalence estimates suggest that about 1 percent of the population may suffer from schizophrenia. It typically emerges in late adolescence or early adulthood.
Positive and Negative Symptoms of Schizophrenia – Positive symptoms of schizophrenia involve behavioural excesses or peculiarities, such as hallucinations, delusions, incoherent thought, agitation, bizarre behaviour, and wild flights of ideas. Negative symptoms involve behavioural deficits such as flattened emotions, social withdrawal, apathy, impaired attention, poor grooming, and poverty of speech.
Delusions in Schizophrenia – Delusions are false beliefs that are maintained even though they clearly are out of touch with reality. Types include reference, persecution, control, grandeur, erotomanic, and somatic delusions.
Hallucinations in Schizophrenia – Hallucinations are sensory experiences that occur without external stimulation, with a compelling sense of reality. Auditory hallucinations (hearing voices) are the most common.
Dopamine Hypothesis of Schizophrenia – The dopamine hypothesis asserts that schizophrenia is linked to excess dopamine activity in the brain, particularly hyperactivity in the mesolimbic pathway. Most drugs useful in treating schizophrenia dampen dopamine activity.
Brain Abnormalities in Schizophrenia – Research has found an association between schizophrenia and enlarged brain ventricles, which are assumed to reflect degeneration of nearby brain tissue. Studies also indicate shrinkage in the hippocampus, thalamus, and amygdala.
Neurodevelopmental Hypothesis of Schizophrenia – The neurodevelopmental hypothesis suggests that vulnerability to schizophrenia is increased by disruptions of normal brain maturational processes before or at birth, potentially due to insults during prenatal development.
Expressed Emotion (EE) – Expressed emotion (EE) in families of schizophrenic patients is characterised by highly critical or emotionally overinvolved attitudes. Studies show that schizophrenic patients returning to families high in expressed emotion have relapse rates about three times that of patients in low EE families.
Diathesis-Stress Model of Schizophrenia – The diathesis-stress model suggests that schizophrenia results from an interaction between genetic vulnerability and environmental stressors, where high stress may precipitate the disorder in someone vulnerable.
Personality Disorders – Personality disorders are characterised by extreme, inflexible personality traits that cause subjective distress or impaired social and occupational functioning. They generally become recognisable during adolescence or early adulthood. The DSM-5 groups personality disorders into three related clusters: anxious/fearful (Cluster C), odd/eccentric (Cluster A), and dramatic/impulsive (Cluster B).
Antisocial Personality Disorder – Antisocial personality disorder is often associated with the term psychopathy. It involves a pervasive pattern of disregard for and violation of the rights of others, including deceitfulness, impulsivity, irresponsibility, and lack of remorse.
Borderline Personality Disorder – Borderline personality disorder is marked by instability in social relationships, self-image, and emotional functioning, as well as impulsivity and frantic efforts to avoid abandonment.
Narcissistic Personality Disorder – Narcissistic personality disorder is characterised by a pervasive pattern of grandiosity, need for admiration, and lack of empathy, including a grandiose sense of self-importance, fantasies of unlimited success, and a sense of entitlement.
Etiology of Personality Disorders – Personality disorders likely involve interactions between genetic predispositions and environmental factors, including early trauma such as physical and sexual abuse.
Autism Spectrum Disorder (ASD) – Autism spectrum disorder (ASD) is included in the neurodevelopmental disorders classification. It is characterised by persistent deficits in social communication and social interaction and restricted, repetitive patterns of behaviour, interests, or activities. Approximately one third of children with autism exhibit subnormal IQ scores. Research suggests that brain overgrowth in individuals with autism may begin sometime around the end of the first year or even during prenatal development. The 1998 study that first reported a link between vaccinations and autism has been discredited as fraudulent.
Culture and Psychological Disorders – Most investigators agree that the principal categories of serious psychological disturbance, such as schizophrenia, depression, and bipolar illness, are identifiable in all cultures. The DSM-5 includes a new Cultural Formulation Interview assessment form to obtain information about the impact of a patient’s culture on key aspects of care. The effects of historical trauma, such as the residential school system in Canada, have significantly impacted the mental health of Indigenous Peoples in Canada. Symptom patterns may vary across cultures; for example, depression in non-Western cultures tends to be expressed more in terms of somatic symptoms. Of the major disorders, symptom patterns are probably most variable for major depressive disorder.
Unifying Themes – Unifying themes include multifactorial causation (most disorders have psychological, biological, and social factors), the interplay of heredity and environment, the sociohistorical context in which psychology evolves, and the influence of culture on psychological phenomena. Most psychological disorders depend on an interaction of genetics and experience, as seen in stress-vulnerability models.

Slides Only

Canadian Healthcare System Emphasis – The Canadian healthcare system emphasizes early intervention, comprehensive treatment, and community-based support for individuals with schizophrenia. It also highlights an integrated care approach for somatic symptom disorder and illness anxiety disorder. Canadian neuropsychiatric units specialize in the assessment and treatment of functional neurological symptom disorder (conversion disorder). Canadian forensic settings have specialized programs for the treatment of antisocial personality disorder.
Subtypes of Delusions (Schizophrenia) – Beyond the general definition, the slides provide specific subtypes of delusions in schizophrenia: reference (irrelevant events have personal significance), persecution (being harassed or conspired against), control (thoughts or actions controlled externally), grandeur (exaggerated self-importance), erotomanic (another person is in love), and somatic (false beliefs about bodily functions).
Subtypes of Hallucinations (Schizophrenia) – The slides detail subtypes of hallucinations: auditory (most common, hearing voices), tactile/olfactory (sensations of touch or smell without external stimuli), and visual (seeing things that aren’t there, less common than auditory).
Negative Symptoms of Schizophrenia (Further Detail) – The slides elaborate on negative symptoms, including affective flattening (reduced emotional expression), alogia (poverty of speech), avolition (lack of motivation), anhedonia (inability to experience pleasure), asociality (lack of interest in social interactions), loss of energy (reduced drive and initiative), and disregarding of social conventions (impaired understanding of social norms).
Brain Degeneration in Schizophrenia – The slides specifically mention progressive structural brain changes in some individuals with schizophrenia, including ventricular enlargement and cortical volume reduction, which may explain a deteriorating course and correlate with symptom severity.
Illness Anxiety Disorder – Characterised by preoccupation with having or developing a serious illness, excessive health-related behaviours or avoidance, absence of or mild somatic symptoms, persistence despite medical evaluation, and significant distress; previously known as hypochondriasis.
Somatic Symptom Disorder – Involves one or more distressing or life-disrupting somatic symptoms, excessive thoughts/feelings/behaviours related to the symptoms, persistent preoccupation (typically >6 months), potentially without medical explanation, with a focus on maladaptive response.
Functional Neurological Symptom Disorder (Conversion Disorder) – Symptoms affecting voluntary motor or sensory function suggesting a neurological condition but incompatible with recognised disorders, not better explained otherwise, often related to psychological stressors, with presentations like weakness, abnormal movement, swallowing difficulties, seizures, and sensory loss.
Specific Personality Disorders and Prevalence in Canada – The slides list each of the ten personality disorders grouped into clusters (Anxious-Fearful, Odd/Eccentric, Dramatic/Impulsive) and provide brief descriptions of their characteristics and estimated prevalence in the Canadian population.
Future Educational and Career Pathways in Canada – The slides outline potential academic and career paths in Canada related to clinical psychology and mental illness, addiction studies, and mental health and well-being streams at universities, highlighting relevant courses and program focuses.

Key Learning Goals

Evaluate the medical model of psychological disorders, and identify the key criteria of abnormality.
Describe recent developments and issues related to the DSM-5 diagnostic system.
Describe the symptoms of generalized anxiety disorder, specific phobia, panic disorder, agoraphobia, OCD, and PTSD.
Discuss how biology, conditioning, cognition, and stress can contribute to the development of anxiety-dominated disorders.
Describe the symptoms of major depressive disorder and bipolar disorder and their relation to suicide.
Understand how genetic, neural, hormonal, cognitive, social, and stress factors are related to the development of depressive and bipolar disorders.
Identify the general characteristics of schizophrenia, and distinguish between positive and negative symptoms.
Explain how genetic and neural factors can contribute to the development of schizophrenia.
Understand the neurodevelopmental hypothesis and how family dynamics and stress can play a role in schizophrenia.
Discuss the nature of personality disorders; the symptoms of antisocial, borderline, and narcissistic personality disorders; and their etiology.
Describe the symptoms, prevalence, and etiology of autism spectrum disorder.
Briefly discuss the issues of psychological disorders and the law.
Reconsider the relativistic and pancultural views of psychological disorders.
Identify the four unifying themes highlighted in the chapter.
Identify the subtypes of eating disorders, and discuss their prevalence.
Outline how genetic factors, personality, culture, family dynamics, and disturbed thinking contribute to eating disorders.
Understand how mental heuristics can distort estimates of cumulative and conjunctive probabilities.

Theories and Frameworks

Medical Model: Proposes abnormal behaviour as a disease. Relevant figures: Not explicitly named in the excerpts. Relevance: Dominant way of thinking about psychological disorders, informs diagnosis, etiology, and prognosis.
Diathesis-Stress Model: Suggests that mental disorders result from an interaction between a predisposition (diathesis) and environmental stressors. Relevant figures: Not explicitly named in the excerpts in this context. Relevance: Explains how vulnerability and stress can lead to the onset of disorders like mood disorders and schizophrenia.
Learned Helplessness: Proposed by Seligman (1974), suggests depression is caused by passive “giving up” behaviour due to exposure to unavoidable aversive events. Relevant figures: Seligman (1974). Relevance: A cognitive theory explaining the development of depressive symptoms.
Evolved Module for Fear Learning (Preparedness): Updated by Ohman and Mineka (2001), suggesting a biological bias to readily acquire fears of ancient threats. Relevant figures: Arne Ohman and Susan Mineka (2001). Relevance: Explains why certain phobias are more common than others.
Dopamine Hypothesis of Schizophrenia: Asserts that excess dopamine activity is the neurochemical basis for schizophrenia. Relevant figures: Not explicitly named as the originator in the excerpts. Relevance: A key neurochemical explanation for schizophrenia, informs treatment strategies.
Neurodevelopmental Hypothesis of Schizophrenia: Proposes that disruptions in normal brain maturation before or at birth increase vulnerability to schizophrenia. Relevant figures: Not explicitly named as the originator in the excerpts. Relevance: Explains the potential early origins of schizophrenia and links to subtle neurological damage.

Research

Rosenhan (as discussed in the chapter): Method: Arranged for normal “pseudopatients” to seek admission to mental hospitals feigning one symptom (hearing voices) and then behaving normally. Results: All were admitted and hospitalised for an average of 19 days; staff often misinterpreted normal behaviour as pathological. Impact on psychology: Evoked controversy about the diagnostic system and raised concerns about diagnostic accuracy and the experience of being labelled mentally ill.
Summerfeldt and Antony et al.: Method: Factor-analysed the symptom structure of 203 Canadians diagnosed with OCD. Results: Found four factors underlying OCD symptoms: obsessions and checking, symmetry and order, cleanliness and washing, and hoarding. Impact on psychology: Suggested that OCD may be a heterogeneous disorder with multiple underlying dimensions, contributing to a more nuanced understanding of the condition.
Alloy and colleagues (1999): Method: Assessed explanatory style in first-year college students (not initially depressed) and followed them for 2.5 years. Results: A negative explanatory style predicted vulnerability to depression, with a significantly higher rate of major depression emerging in students with negative thinking. Impact on psychology: Provided strong evidence for a causal link between negative cognitive styles and vulnerability to depression, supporting cognitive theories.
Twin Studies (various researchers): Method: Compared concordance rates for various psychological disorders (anxiety, mood disorders, schizophrenia, personality disorders) between identical and fraternal twins. Results: Generally found higher concordance rates for identical twins compared to fraternal twins across many disorders. Impact on psychology: Provides strong evidence for a genetic predisposition to many psychological disorders, highlighting the role of heredity.
Studies of Expressed Emotion (EE) (e.g., Leff & Vaughn, 1985): Method: Assessed the degree to which relatives of schizophrenic patients displayed critical or emotionally overinvolved attitudes (EE) through audiotaped interviews and followed patient relapse rates. Results: Patients returning to families high in EE had significantly higher relapse rates compared to those in low EE families. Impact on psychology: Demonstrated the significant role of family environment in the course of schizophrenia, leading to interventions aimed at reducing EE.

The Kitchen Sink

Criteria of Abnormality: Behaviour is judged as abnormal when it becomes extremely deviant, maladaptive, or personally distressing. Normality and abnormality exist on a continuum. Diagnoses involve value judgments.
Dimensional vs. Categorical Approach to Diagnosis: The DSM-5 primarily retains a categorical approach, though supplemented with dimensional approaches in some areas. A dimensional approach would describe disorders in terms of continuous dimensions like anxiety or depression. The shift to a dimensional approach proved logistically difficult and controversial.
Stereotypes of Violence and Mental Illness: Only a modest association exists between mental illness and violence. Media attention on violent incidents involving the mentally ill contributes to this inaccurate stereotype.
Taxonomy of Mental Disorders: A sound taxonomy facilitates empirical research and enhances communication among scientists and clinicians.
Growth of DSM: The number of diagnoses has grown dramatically since the first edition.
Most Common Psychological Disorders: In North America, these include substance use disorders, anxiety disorders, and depression.
Sound Taxonomy Goal: The primary goal is to facilitate empirical research and enhance communication.
DSM-5 Release Year: 2013.
RDoC Purpose: Primarily for research.
Expressed Emotion Definition: Highly critical or emotionally overinvolved attitudes toward a schizophrenic patient.
Fitness to Stand Trial: A defendant may be found unfit if unable to conduct a defence due to a psychological disorder.
Culture-Bound Disorders (DSM-IV-TR): Specific disorders seemingly occurring only in certain cultures, like amok (Malaysian) and brain fag (West African).
Somatic Symptoms in Depression (Non-Western Cultures): Depression tends to be expressed more through physical complaints like fatigue or headaches than psychological symptoms.
Eating Disorders (General): Characterised by preoccupation with weight and unhealthy efforts to control it. Anorexia nervosa, bulimia nervosa, and binge-eating disorder are included. More common in Western, affluent cultures.
Medical Student’s Disease: The tendency to see oneself and friends in descriptions of pathology.
Representativeness Heuristic: Can lead to underestimation of mental disorder prevalence by equating them with severe disorders.
Availability Heuristic: Can lead to overestimation of violence among the mentally ill due to media coverage.
Conjunctive Probability: The probability of multiple events occurring together, which is generally lower than the probability of any single event.
Cumulative Probability: The probability of at least one of several events occurring, which increases with more events.

Notable Individuals

Here is a list of important figures mentioned in the sources with a very brief summary of their importance:
Rosenhan: Conducted a study involving pseudopatients feigning hearing voices to gain admission to psychiatric hospitals, highlighting issues with diagnostic accuracy and the experience of being hospitalised for mental illness.
Thomas Szasz: Known for his critical views on the medical model of mental illness, suggesting that “minds can be ‘sick’ only in the sense that jokes are ‘sick’ or economies are ‘sick!’”.
Romeo Dallaire: A Canadian Forces General who commanded the UN Assistance Mission for Rwanda and later suffered from PTSD, illustrating the impact of traumatic experiences.
Percy Paul: A gifted mathematician in Canada who suffers from bipolar disorder, showing that individuals with mental illness can still achieve greatness.
Seligman: Proposed the theory that depression is caused by learned helplessness, the passive “giving up” behaviour produced by exposure to unavoidable aversive events. He later reformulated this theory to emphasise pessimistic explanatory styles.
Alloy and colleagues: Found that a negative explanatory style in college students predicted vulnerability to depression.
Faravelli and Pallanti: Their research suggested that stress may contribute to the development of panic disorder.
Arne Ohman and Susan Mineka: Updated the notion of preparedness for phobias, calling it an evolved module for fear learning, suggesting some fears are more easily acquired due to evolutionary history.
Laura Summerfeldt and Martin Antony: Research suggests that OCD may be a heterogeneous disorder with multiple underlying factors based on their factor analysis of OCD symptoms in Canadians.
Howie Mandel: A Canadian comedian and TV personality who is very public about his OCD, particularly his fear of germs, helping to raise awareness.
Homer and Langley Collyer: Two wealthy brothers in New York City known for their extreme hoarding behaviour, which is now recognised as hoarding disorder in the DSM-5.
Sheila Woody: Heads the Hoarding Hub at the University of British Columbia, conducting research and treatment initiatives for compulsive hoarding.
John Nash: A Nobel Prize-winning mathematician who struggled with paranoid schizophrenia, known for the book and film “A Beautiful Mind”.
Anne Bassett: Holds the Canada Research Chair in Schizophrenia Genetics and Genomic Disorders at the University of Toronto, focusing on the genetics of schizophrenia.
Robert Hare: A leading expert on psychopathy, often used interchangeably with antisocial personality disorder, and developed the Psychopathy Checklist-Revised (PCL-R).
Donald Triplett: Identified as the first person diagnosed with autism, providing a historical perspective on the disorder.
Lori Triano-Piovesan: A case mentioned in the context of the insanity defence in Canadian law, having been found not criminally responsible for the murder of her neighbour due to paranoid schizophrenia.
Regina Schuller: A psychologist and expert on the interface of psychology and Canadian law, including the insanity defence (NCRMD).
James Ogloff: Another expert mentioned in relation to the insanity defence and the increased demand for psychological expertise in legal settings.
Zachary Turner: A young child whose death led to discussions about the ability of the criminal justice system to address mental health issues, although not a figure directly involved in research.
Matt Dunigan: A former CFL quarterback who suffered career-ending concussions and agreed to donate his brain to concussion research, highlighting the link between head trauma and mental health.
Tversky and Kahneman: Researchers who studied cognitive heuristics and biases, including the conjunction fallacy, which can affect how people think about the probabilities of mental illness and other events.