Phobias
- Created by: Alice
- Created on: 28-05-15 10:07
Classification and Diagnosis of Phobic Disorders
Validity: Refers to the extend that a diagnosis represents something that is real and distinct from other disorders and the extent that a classification system such as ICD
- Comorbidty: Refers to the extent that two conditions co-occur
Kendler et al: Research has found high levels of comorbidty between social phobias, animal phobias, generalised anxiety disorders and depression
- Concurrent: Establishes value of a new measure of phobic symptoms by correlating it with an existing one.
Herbert et al: Established concurrent validity of social phobia anxiety inventory (SPAI) by giving the test and various other standard measures of 23 social phobics - SPAI correlated well with other measures
- Construct: Measures extent that a test for phobic disorders really does measure a target construct of phobias
Clinicians identify possible target behaviours that we would expect in someone with a phobic disorder and see if people who score high on the test for phobic disorders also exhibit target beahaviour.
Classification and Diagnosis of Phobic Disorders
Evaluation
- Comorbidty: Eysenck reported that up to 66% of patients with one anxiety - The implication is that a diagnosis should simply be 'anxiety disorder' rather than a phobia
- Concurrent: Mattrick and Clarke showed their social phobia scale correlated well with other standard measure. This indicated there are methods of diagnosis that agree - measures that something is real
- Construct: Beidel et al: SPAI correlates well with behavioural measures of social phobia but doesn't correlate well with behaviours related to other anxiety disorders.
- Implication of low reliability/validity: Researchers require a reliable and valid means ofassessing disorders in the first place
Classification and Diagnosis of Phobic Disorders
Reliability: Reliability of such questionnaires or scales can be measured in terms of whether two independent assessors give imilar scores (inter-rater) or whether the test items are consistent (test-retest)
- Inter-rater: Skyre: Asked 3 clincians to assess 54 patient interview obtained using structured clinical interview. They found high inter-rater agreement (+72) = reliable
- Test-retest: Scales such as SCID takes 1-2 hours to complete. The alternatice is to use shorter, structured, self-administered sclaes.
Popular for specific phobias: For example Hiller et al - MDC reported satisfactory to excellent diagnostic agreement in test-restest using MDC
Classification and Diagnosis of Phobic Disorders
Evaluation:
Research Evidence: SCID requires extensive training which may explain high reliability
- Kedler et al used face-to-face and telephone interview over a one month interval (test-retest) and found a mean agreement of +46. Over long term (8 years) found a mean agreement of +30
Reasons for low reliability: Kendler et al: test-retest reliability might be due to the poor recall by participants of their fears - people tend to over-exaggerate fears when recalling previous distress.
- Low inter-rater reliability might be due to different decisions made by interviewers when deciding if the severity of a symptom does or does not exceed the clinical threshold for a symptom.
Biological Explanations of Phobic Disorders
Evolutionary Factors:
Ancient Fears: Some stimuli are more likely to be feared than others - snakes, heights, storms: reflected real danger to our ancestors
Prepotency: Natural selection has shaped our nervous system so that we attend more to certain cues than others - something that has power prior to direct experience
Preparedness: Humans are biologically prepared to rapidly learn an association between particular stimuli and fear. This association is difficult to extinguish
Biological Explanations of Phobic Disorders
Evaluation:
Prepotency: Ohman and Soares: Masked picture were constructed of feared objects so they were not easily recognisable. Participants who were fearful of snakes showed greater GSR when briefly showed masked photos - prepotent signals
Preparedness: Mc Nally concluded that there was firm evidence for changed resistance to the extinsion of fear responses conditioned by 'prepared' stimuli
Clinicial Phobias: Much of the research is concerned with avoidance responses rather than clinical disorders - Merckelbach found that most of clinical phobias were rated as non-prepared rather than prepared
Biological Explanations of Phobic Disorders
Genetic Factors
Family Studies: Fyer et al: Found that probands had 3 times as many relative who also experienced phobias as normal controls
- Solyom et al: Found that 45% of phobic patients had a least one relative with the disorder, compared to a rate of 17% of non-phobic controls
Twin Studies: MZ twins are genetically identical a closer concordance rate between MZ and DZis evidence for a genetic basis
- Torgersen: Compared MZ and DZ twin pairs where one twin had an anxiety disorder - such disorders were 5x more frequent in MZ
What is inherited? Oversensitive fear response - explained in terms of the ANS. There may be abnormally high levels of arousal in the ANS which leads to increased amounts of adrenlaline - adrenergic theory
Biological Explanations of Phobic Disorders
Evaluation:
Family and Twin Studies: Torgerson only found 31% concordance for MZ twins in terms of anxiety disorders and almost not concordance for DZ twins - fails to control for shared environmental experiences
The diathesis stress model: Genetic factors predispose an individual to develop phobias but life experiences play an important rolein triggering such responses
What is inherited: Tiihonen foudn singinificantly lower number of such sites in patients with social phobias than in normal controls - the low number of sites lead to abnormal low levels of dopamine
Psychological Explanation of Phobic Disorders
Behavioural
Classical Conditioning: Fears are acquired when an individual associates a neutral stimulus with a fear response - Case study of Little Albert
Operant Conditioning: Mowrer the 2nd stage of acquiring phobias - the avoidance of the phobic stimuli trduces fear and is thus reinforcing
Social Learning: May also be acquired through modelling the behaviour of others
Psychological Explanation of Phobic Disorders
Evaluation
Conditioning: Not everyone who has a phobia can recall such an incident. For example not everyone who was bitten by a dog would develop a phobia suggested by the diathesis stress model - only those with a genetic vulnerablity would develop a phobia
Biological Preparedness: Phobias do not always develop after a traumatic incident - fear responses are only learned with living animals
Soical Learning: Bandura and Rosenthal suggested that a model experienced pain every time a buzzer sounded. Participants who observed this showed an emotional reaction to the buzzer
Sue et al: Suggested that different phobias may be the result of different processes
Psychological Explanation of Phobic Disorders
Cognitive: Phobias may develop as the consequence of irrational thinking
- Aaron Beck proposed that phboias arise because people become afraid of situations where fears may occur
- Tend to overestimate their fears
Evaluation
Dysfunctional assumptions: Gournaly found that phobics were more likely than normal people to overestimate risks - more fearful being more predisposed to develop phobias
Success of cognitive behavioural therapy: If a therapy changes the dysfunctional assumptions a person has and leads to a reduction in their phobia- then dysfunctional assumptions may originally have caused the disorder.
Psychological Explanation of Phobic Disorders
Psychodynamic:
Freud: A phobia is the conscious expression or repressed conflicts. The ego deals with conflict by protecting itself and repressing emotions into the unconscious mind
- Repressed conflicts = greater anxiety
- Deals with this through dreams or displacing onto a netural object
- Research Support: Little Hans
- Bowlby: Found that agoraphobics often had early experiences of family conflict. He suggested that such conflict leads a young child to feel very anxious when separated from their parents
Evaluation:
Little Hans: Only provided one piece of research, can easily be explained by classical conditioning - unique to the individual and cannot be generlaised.
Biological Therapies for Phobic Disorders
Chemotherapy:
Benzodiazepines: Slow down activity of central nervous systems by enhancing the activity of GABA - this has a quieting effect on many of the neurons
Beta-blockers: Reduce the activity of nora/adrenaline - bind to receptors causing the heart to beat slower with less force - fall in blood pressure - less stress on the heart
Anti-depressants: SSRIs - increase the levels of serotonine which regulates mood and anxiety
Evaluation:
- Not a cure: Drugs are not considered the primary treatment for phobias - simply focus on the symptoms rather than the cause
- Side Effects: Side effects of BZs include aggressiveness and long-term impairment of memory
- Addiction: BZs are very addictive - as a result used a maximum of 4 weeks
Biological Therapies for Phobic Disorders
Psychosurgery
Capsulotomy and Cingulotomy: Remove the capsule and cingulum - the connection with the organ are severed. Both part of the limbic system - irreversible
Transcanial Magnetic Stimulation: Insert a probe through top of the skull, pushes it into the capsule, the tip burns small portions of the tissue.
Deep Brain Stimulation: Placing wires in target region of the brain - when the current is on it interrupts target circuitthus reducing symptoms
Evaluation:
- Issues studying the effectiveness of drugs
- Substituting a placebo for an effective treatment does not satisfy this duty as it exposes individuals to a treatment known to be inferior
- Informed consent: Not informed about comparative success of drugs versus placebos
- Irreversible forms of psychosurgery
Psychological Therapies for Phobic Disorders
Cognitive Therapy: REBT
Ellis proposed that the way to deal with irrational thoughts was to identify them using the ABC model
A - Activating Event
B - Belief
C - Consequences
Disputing: Focuses on challenging or disputing the beliefs and replacing them with effective rational beliefs
- Logical Disupting: Self-defeating beliefs do not follow logically from information available
- Empirical Disputing: Self-defeating beliefs may not be consistent with reality
- Pracmatic Disputing: Emphasisesthe lack of usefulness of self-defeating beliefs
self defeating ------> rational
Psychological Therapies for Phobic Disorders
Evaluation:
Not suitable for all: Ellis believed that sometimes people who claimed to be following REBT principles were not putting their revises beliefs into action and therefore was not effective
- Some do not want the direct advice
Theorestical basis: Alloy and Abrahmson found depressed people gave more accurate estimates of the likelihood of a disaster than formal controls
Psychological Therapies for Phobic Disorders
Behavioural Therapy: Systematic Desentisation
Counterconditioning: Begins with learning relaxation techniques - acquire a new stilumus - response link - responding to feared stimulus with relaxation.
- Taught how to relax their muscles
- Construct desentisisation hierarchy -series of imagine scenes
- Work way through hierarchy - visualising each event
- Once mastered one step - ready to move on
- Masters feared stimulus
Different forms of SD:
- Vivo - confront feared stimulus directly
- Covert - Imagine presence of it
Psychological Therapies for Phobic Disorders
Evaluation:
Effectiveness: Mc Grath et al - reported that about 75% of patient with phobias to SD
Appropriateness:
- Symptom Substitution: May appear to resolve a problem but simply substitution/eliminating or supressing symptoms can result in other symptoms
- Is relaxation necessary? Might be that the expectation of being able to cope with feared stimulus
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