Chapter 14: Psychological Disorders
Abnormal Behaviour: Myths, Realities, and Controversies
The Medical Model Applied to Abnormal Behaviour
The medical model proposes that it is useful to think of abnormal behaviour as a disease.
−Can be seen in the terms referring to abnormal behaviour, mental illness, psychological disorder
−Prior to the rise of the medical model, conceptions of abnormal behaviour were based on
superstition (demonic possession, in league w/ the devil etc.), which meant harsh treatment of
the mentally ill.
−Szasz argues that abnormal behaviour usually involves a deviation from social norms rather than
an illness, and that the medical model’s disease analogy converts moral and social questions
about acceptable behaviour into medical questions
*Important Medical Concepts
Diagnosis: distinguishing one illness from another
Etiology: the apparent causation and developmental history of an illness
Prognosis: a forecast about the probable course of an illness
Criteria of Abnormal Behaviour
In making diagnoses, clinicians rely on a variety of criteria:
(1) Deviance – when people violate social standards and expectations, they may be labelled as
(2) Maladaptive behaviour – when people are judged to have a psychological disorder b/c their
everyday adaptive behaviour is impaired.
(3) Personal distress – based on an individual’s report of great personal distress.
−People are often viewed as disordered when only one criterion is met, though more are possible
−Psychological disorder diagnoses involve value judgements about prevailing cultural values, social
trends and political forces, as well as scientific knowledge (basically, what is normal, and how far
from normal are you?)
−People are only judged to be mentally ill when their behaviour becomes extremely deviant (the
normal-abnormal is a spectrum, not a either/or)
Stereotypes of Psychological Disorders
*Myths of Psychological Disorders
(1) Psychological disorders are incurable. The vast majority of people who are diagnosed as
mentally ill eventually improve and lead normal, productive lives.
(2) People with psychological disorders are often violent and dangerous. There’s no consistent
link b/w mental illness and violence, only past history of violence and violence.
(3) People with psychological disorders behave in bizarre ways and are very different from
normal people. This is only true in a minority of cases, usually involving relatively severe
Psychodiagnosis: The Classification of Disorders
−A sound diagnosis system is the Diagnostic and Statistical Manuel of Mental Disorders, written by
the American Psychiatric Association. The current, fourth edition (DSM-IV) refined the criteria in
the detailed third edition w/ use of research.
−DSM-III introduced a new multiaxial system of classification which asks for judgements about
individuals on 5 separate dimensions, or “axes.”
−Clinicians record most disorders in Axis I; Axis II is used to list long-running personality or
mental retardation. Axis III is for a patient’s physical disorders, Axis IV for the types of stress
experienced by the individual in the previous year, and on Axis V, estimates are made of the
individual’s current level of adaptive functioning and of the individual’s highest level of
functioning the previous year. **For the full tables of the Axes, see pg 610.
Prevalence of Psychological Disorders
−Estimates of the commonality of psychological disorders falls in the domain of epidemiology—the
study of the distribution of mental or physical disorders in a population.
−In epidemiology, prevalence refers to the percentage of a population that exhibits a disorder
during a specified time period. In the case of mental disorders, lifetime prevalence refers to the
percentage of people who endure a specific disorder at any time in their lives.
−Estimates of lifetime prevalence increased from 1/5th to 1/3rd of the population after the
publishing of DSM-III, b/c alcohol and drug-related disorders weren’t assessed. Figures vary, and
the largest estimate of the lifetime risk of a psychiatric disorder is 51%.
−Overall, 10% of Canadians 15+ report some sort of disorder. Eating disorders increased by 34%
b/w 1987 and 1999
Def: class of disorders marked by feelings of excessive apprehension and anxiety
−5 main types: generalized, anxiety, phobic, panic, and agoraphobic, OCD and PTSD
Generalized Anxiety Disorder
Def: marked by a chronic, high level of anxiety that is not tied to any specific threat.
−Also known as free-floating, b/c it’s non-specific
−People worry, worry about how much they worry, hope that their worrying will help ward off
negative events, dread decisions b/c that leads to brooding
−Physical symptoms: trembling, muscle tension, diarrhea, dizziness, faintness, sweating, and
−Gradual onset, seen more in females than males
Def: marked by a persistent and irrational fear of an object or situation that presents no realistic
−Accompanied by physical symptoms of anxiety, such as trembling and palpitations
−Certain types of phobias are more common than others, like acrophobia (fear of heights),
claustrophobia (fear of small spaces), brontophobia (fear of storms), etc. For some, even
imagining the object or situation can trigger great anxiety.
Panic Disorder and Agoraphobia
Def: characterized by recurrent attacks of overwhelming anxiety that usually occur suddenly and
−Paralysing panic attacks are accompanied by physical symptoms of anxiety
−The unexpectedness of their panic attacks may make them so concerned about exhibiting panic
in public that they might be afraid to leave home, creating the condition called agoraphobia
−Although agoraphobia was traditionally viewed as a phobic disorder, recent evidence suggests
that agoraphobia is mainly a complication of panic disorder.
−2/3rds of patients are female
−onset typically occurs during late adolescence or early adulthood
Def: marked by persistent, uncontrollable intrusions of unwanted thoughts (obsessions) and urges to
engage in senseless rituals (compulsions)
−Obsessions sometimes centre on inflicting harm, personal failures, suicide, or sexual acts.
−Compulsions involve stereotyped rituals that temporarily relieve anxiety Ex. constant hand-
washing, repetitive cleaning of things that are already clean
−Most cases of OCD appear before the age of 35
Post-Traumatic Stress Disorder (PTSD)
−Elicited by any traumatic event, Ex. rape, natural disaster, witnessing someone’s death
−Sometimes PTSD doesn’t surface until months after the event
−Symptoms: re-experiencing the traumatic event in the form of nightmares and flashbacks,
emotional numbing, alienating, problems in social relationships, an increased sense of
vulnerability and elevated levels of arousal, anxiety, anger, and guilt
−The more intense the exposure to the event, or the more intense one’s reaction was at the time
of the event, the more vulnerable the person is to PTSD
−PTSD symptoms decline in severity and frequency over time, but recovery is gradual, and the
symptoms don’t necessarily disappear completely
Etiology of Anxiety Disorders
−In studies that assess the impact of heredity on psychological disorders, investigators look at
concordance rates – indicates the percentage of twin pairs or other pairs of relatives who exhibit
the same disorder if relatives who share more genetic similarity show higher concordance rates
than relatives who share less genetic overlap, this supports the genetic hypothesis
−The results of twin studies and family studies suggests that there is a moderate genetic
predisposition to anxiety disorders
−Anxiety sensitivity may make people more vulnerable to anxiety disorders; some people are
highly sensitive to the internal physiological symptoms of anxiety and are pronen to overreact w/
fear when they experience these symptoms. Anxiety sensitivity may fuel an inflationary spiral in
which anxiety breeds more anxiety, which eventually spins out of control into an anxiety disorder.
−Disturbances in GABA activity may play a role in anxiety disorders, same goes for serotonin in
panic and OCD.
Conditioning and Learning
−Many anxiety responses may be acquired through classical conditioning and maintained through
operant conditioning, Ex. a child buried in a avalanche fears snow as an adult
−Once a fear is acquired through classical conditioning, the person may start avoiding the anxiety-
producing stimulus, which is negatively reinforced b/c it is followed by a reduction in anxiety
−Seligman’s concept of preparedness states that people are biologically prepared by their
evolutionary history to acquire some fears much more easily than others (ie. Snakes). updated
as the evolved module for fear learning by Ohman and Mineka, who maintain that this module is
activated by stimuli related to survival threats in evolutionary history
−Criticism: many ppl w/ phobias cannot identify a traumatic conditioning exp that led to the
phobia, while others who endure traumatic events who should have phobias don’t.