Download PPT

Anxiety Disorders
PSY4080 6.0 D
Anxiety Disorders
1
Anxiety Disorders:
Prevalence, general information

Anxiety disorders - among the most prevalent disorders of
childhood and adulthood (Prevalence of 1 -25% - Gelfland,
2002)
 To be a disorder, it must interfere with daily functioning.
 Most prevalent:
1. Obsessive compulsive disorder (OCD)
2. Generalized anxiety disorder (GAD)
3. Social Phobias and Panic Disorders
PSY4080 6.0 D
Anxiety Disorders
2
About Anxiety Disorders
Physical Aspect
 Stress: generally a physiological state associated with
anxiety - heightened arousal with physical symptoms
Psychological Aspect
 Anxiety: a feeling of anticipation (negative) or worry in a
particular context - no specific target is necessary
 Fear: often used interchangeably - usually used in
reference to a specific target
 Axiogenic: anxiety producing
 Axiolytic: anxiety reducing
PSY4080 6.0 D
Anxiety Disorders
3
The Stress Response
Hypothalamic-Pituitary-Adrenal (HPA) Axis
 Hypothalamus releases of corticotropin releasing
hormone (CRH)
 Pituitary gland releases (adreno)corticotropin
hormone
 Cortisol, epinephrine, norepinephrine (and other
adrenal hormones) released from adrenal glands
• Increasing energy, awareness in response to a threat
• Increase heart rate, sweating, heavier breathing,
increase in muscle tension, etc.
• Preparation of fight or flight
PSY4080 6.0 D
Anxiety Disorders
4
PSY4080 6.0 D
Anxiety Disorders
5
The Stress Response
 The hypothalamus is a the centre of the stress
response via the sympathetic nervous system.
 However, projections from the amygdala and
prefrontal areas to the hypothalamus influence
how threatening situations are interpreted and,
hence, regulated
• Structures involved in establishing classical and operant
learning
PSY4080 6.0 D
Anxiety Disorders
6
The Stress Response
 CRH receptors found throughout the mesocortical
pathway: Prefrontal, cingulate, amygdala,
nucleus accumbens, locus coeruleus
 Of course, epinephrine (adrenalin) and
norepinephrine also act in similar areas.
PSY4080 6.0 D
Anxiety Disorders
7
Development and Maintenance
of Fear
Two Factor Theory
1. Fears develop by classical conditioning:
•
A neutral event is associated with a fearful
event
•
Fear elicited by neutral event
2. Fear is maintained by operant conditioning
•
Avoidance of fear inducing situation (negative
reinforcement)
PSY4080 6.0 D
Anxiety Disorders
8
Neuropathology: Learning Anxiety
Producing Behaviours

1.
2.


The amygdala and pre-frontal areas play an
important role in learning of fear-based
behaviours
Amygdala: contextual learning and (re)consolidation.
Frontal lobe: extinction memory.
Both areas implicated in processing incoming
conditioned stimulus information.
Anxiety producing behaviours associated with
increased hippocampal and reduced frontal
activation.
PSY4080 6.0 D
Anxiety Disorders
9
Neuropathology: Learning Anxiety
Producing Behaviours
Neurotransmitter Systems
1. Glutamate (NMDA receptor)
 NMDA receptor is ionotropic: slow, long lasting
depolarization.
 Present in amygdala and prefrontal areas
 Also a number of brainstem areas associated
with stress response (locus coeruleus, ventral
tegmental area, periadaqueductal grey matter)
PSY4080 6.0 D
Anxiety Disorders
10
Neuropathology: Learning Anxiety
Producing Behaviours
Neurotransmitter Systems
2. GABA (A-receptor subtype)
 Implied through the effects of GABAA agonist
benzodiazapine
 Sedative used in the treatment of anxiety and
insomnia
 Large reductions in GABA concentrations, not
clearly linked to mesocortical pathway
 Receptor disruption through other modulator
steroids
PSY4080 6.0 D
Anxiety Disorders
11
Neuropathology: Learning Anxiety
Producing Behaviours
Neurotransmitter Systems
3. Norepinephrine
 Locus coeruleus: Arousal, vigilance
 Limbic and frontal cortex: elaboration, adaptive
responses to stress
 Long term potentiation in medial PFC

Sustained stress producing reduction in number of NE
2 receptors
PSY4080 6.0 D
Anxiety Disorders
12
Neuropathology: Learning Anxiety
Producing Behaviours
Neurotransmitter Systems
4. Corticotropin Releasing Hormone
 Mediation of response to stress
 In amygdala: occurrence of fear related
behaviours
 In cortex: reduction reward expectation
 Memory systems may be particularly sensitive
to the effects of CRH in early life.
PSY4080 6.0 D
Anxiety Disorders
13
Neuropathology: Learning Anxiety
Producing Behaviours
Neurotransmitter Systems
5. Serotonin
 Has both anxiogenic and anxiolytic effects





2A-receptor subtype is anxiogenic
1A-receptor subtype is anxiolytic
1A receptor knockout mice have increased
anxiety-related behaviours
High levels of CRH and cortisol down-regulate
1A receptors in early life
Receptors found along the mesocortical
pathway
PSY4080 6.0 D
Anxiety Disorders
14
Obsessive-Compulsive Disorder:
DSM-IV Criteria
A.
1. recurrent and persistent thoughts, impulses, or images
that are experienced, at some time during the
disturbance, as intrusive and inappropriate and that
cause marked anxiety or distress
2. the thoughts, impulses, or images are not simply
excessive worries about real-life problems
PSY4080 6.0 D
Anxiety Disorders
15
OCD: DSM-IV Criteria
3. the person attempts to ignore or suppress such
thoughts, impulses, or images, or to neutralize them with
some other thought or action (compulsion)
4.the person recognizes that the obsessional thoughts,
impulses, or images are a product of his or her own mind
(not imposed from without as in thought insertion)
PSY4080 6.0 D
Anxiety Disorders
16
OCD: DSM-IV Criteria
Compulsions
1. repetitive behaviors (e.g., hand washing, ordering, checking)
or mental acts (e.g., praying, counting, repeating words
silently)
 person feels driven to perform in response to an obsession
 according to rules that must be applied rigidly
2. behaviors or mental acts are aimed at preventing or reducing
distress or preventing some dreaded event or situation;
 not connected in a realistic way with what they are designed
to neutralize or prevent or are clearly excessive
PSY4080 6.0 D
Anxiety Disorders
17
OCD: DSM-IV Criteria
B. At some point, the person has recognized that the obsessions or
compulsions are excessive or unreasonable.
Note: This does not apply to children.
C. The obsessions or compulsions cause marked distress, are time
consuming (take more than 1 hour a day), or significantly interfere
with the person’s normal routine, occupational (or academic)
functioning, or usual social activities or relationships.
PSY4080 6.0 D
Anxiety Disorders
18
OCD: DSM-IV Criteria
D. If another Axis I disorder is present, the content of the obsessions or
compulsions is not restricted to it
(e.g, preoccupation with food in the presence of an Eating Disorder;
preoccupation with drugs in the presence of a Substance Use
Disorder.
E. The disturbance is not due to the direct physiological effects of a
substance (e.g., a drug of abuse, a medication) or a general medical
condition.
PSY4080 6.0 D
Anxiety Disorders
19
More information
 Obsessions are very difficult to repress despite their
unpleasant nature.
 Obsessions and compulsions can occur independently.
 Common compulsions include washing, checking
behaviours, order, and symmetry.
PSY4080 6.0 D
Anxiety Disorders
20
Generalized Anxiety Disorder: DSM-IV
A. Excessive anxiety and worry (apprehensive
expectation), occurring more days than not for at least 6
months, about a number of events or activities (such as
work or school performance).
B. The person finds it difficult to control the worry.
PSY4080 6.0 D
Anxiety Disorders
21
GAD: DSM-IV Criteria
C. The anxiety and worry are associated with three (or
more) of the following six symptoms :
1. muscle tension
2. being easily fatigued
3. Irritability
4. sleep disturbance (difficulty falling or staying asleep, or
restless unsatisfying sleep)
5. restlessness or feeling keyed up or on edge
6. difficulty concentrating or mind going blank
PSY4080 6.0 D
Anxiety Disorders
22
GAD: DSM-IV Criteria
D. The focus of the anxiety and worry is not confined to
features of an Axis I disorder, e.g., the anxiety or worry is
not about having a Panic Attack (as in a Panic Disorder),
being embarrassed in public (as in Social Phobia).
E. The anxiety, worry, or physical symptoms cause clinically
significant distress or impairment in social, occupational,
or other important areas of functioning.
PSY4080 6.0 D
Anxiety Disorders
23
GAD: DSM-IV Criteria
F. The disturbance is not due to the direct physiological
effects of a substance (e.g., a drug of abuse, a
medication) or a general medical condition (e.g.,
hyperthyroidism) and does not occur exclusively during a
Mood Disorder, a Psychotic Disorder, or a Pervasive
Developmental Disorder.
PSY4080 6.0 D
Anxiety Disorders
24
Social Phobia
 Fear is centred on some aspect of the social
situation.
 Children fear a teacher, being called on in class,
or even entering the classroom.
 Adults may fear public speaking, social
interaction, or initiation of conversations
 Symptoms are similar to fear response associated
with all phobias.
PSY4080 6.0 D
Anxiety Disorders
25
Social Phobia: DSM-IV
A. Marked and persistent fear of one or more social and
performance situations in which the person is exposed to
unfamiliar people or to possible scrutiny by others.
 The individual fears that he or she will act in a way (or
show anxiety symptoms) that will be humiliating or
embarrassing.
 Note: In children, there must be evidence of the capacity
for age-appropriate social relationships with familiar
people and the anxiety must occur in peer settings, not
just in interactions with adults.
PSY4080 6.0 D
Anxiety Disorders
26
Social Phobia: DSM-IV
B. Exposure to the feared social situation almost invariably
provokes anxiety, which may take the form of a
situationally bound or predisposed Panic Attack.
 Note: In children, the anxiety may be expressed by
crying, tantrums, freezing, or shrinking from social
situations with unfamiliar people.
C. The person recognizes that the fear is excessive or
unreasonable.
 Note: In children, this feature may be absent
PSY4080 6.0 D
Anxiety Disorders
27
Social Phobia: DSM-IV
D. The feared social or performance situation are avoided
or else are endured with intense anxiety or distress
E. The avoidance, anxious anticipation, or distress in the
feared social or performance situation(s) interferes
significantly with the person's normal routine,
occupational (academic) functioning, or social activities
or relationships, or there is marked distress about having
the phobia.
F. In individuals under age 18 years, the duration is at least
6 months
PSY4080 6.0 D
Anxiety Disorders
28
Social Phobia: DSM-IV
G. The fear or avoidance is not due to the direct
physiological effects of a substance (e.g., a drug of
abuse, a medication) or a general medical condition and
is not better accounted for by another mental disorder.
H. If a general medical condition or another mental disorder
is present, the fear in Criterion A is unrelated to it.
 Usually refers to realistic fears
PSY4080 6.0 D
Anxiety Disorders
29
Panic Disorder
 When panic attacks due to anxiety and fear occur regularly,
may have panic disorder
 Sudden feelings of terror that occur suddenly and without
warning
 Symptoms vary but may include:
•
•
•
•
•
Chest pain.
Heart palpitations
Shortness of breath.
Dizziness.
Abdominal distress
PSY4080 6.0 D
Anxiety Disorders
30
Some Etiology
 Begins in young adulthood--may or may not be
linked to a particular traumatic experience
 Evidence that heightened fear response begins in
early childhood
 Related to neurological syndromes, like epilepsy,
Tourette’s, lesions (encephalitis, TBI)
 Some patients have damage or dysfunction of
basal ganglia, cingulate gyrus, prefrontal cortex
(Giedd et al., 1995; Robinson et al., 1995)
 Difficulty with extinction
PSY4080 6.0 D
Anxiety Disorders
31