Phobias & SAD and GAD & PD

• Emotional symptoms
• Cognitive symptoms
• Physiological symptoms
• Behavioral symptoms

- Watson & Raynor (1920): “little Albert”

- extension by Mowrer (1960) conditioning is mediated by motivations such as

desire to reduce fear, accounts for avoidance behavior

Shortcomings (Rachman et al. 1991 for review)

- all stimuli can become feared stimuli (the equipotenitality premise)

- many people experience aversive conditioning but do not develop a phobia

- traumatic etiology is not reported by all phobic individuals

- limited success of studies that have endeavored to condition stable fears in human in an experimental setting

• learning by observing reactions of others Bandura & Rosenthal, 1966 Bobo Doll experiment.
• Verbal information (e.g. media, Rachmann, 1991)
• witnessing someone else have a fearful reaction or upsetting social experience

Seligman (1971) phobic stimuli are biologically threatening humans are biologically prepared to develop fears of stimuli that threaten personal safety

four features of prepared phobias:

- acquired through one-trial conditioning

- non-cognitive

- phobic object involves threat to humankind, result of natural selection

- not easily extinguished

Rachman (1991) several alternative pathways

(direct conditioning, model learning, verbal acquisition)

evidence:

- Bandura (1966): participants had to watch person receiving electro-shock,

resulted in increase in physiological response by just viewing apparatus

- Cook and Mineka (1989): monkeys watched videotapes of monkeys behaving

fearfully to either fear relevant (snakes, crocodiles) fear irrelevant stimuli (flowers,

rabbits, development of fear of the fear-relevant stimuli, replicated by several studies

- acquisition via verbal information in the epidemics of koro in Singapore and Thailand.

The epidemics were thought to have been caused by verbal transmission via media

(Rachman 1991)

- increases in skin conductance in response to target stimulus after information that stimulus

would be followed by a shock (Cook & Harris 1937)

Phobias may be acquired without previous direct or indirect

associative learning (Menzies and Clarke 1995)

evidence:

- (Menzies & Clarke, 1993): Interviewing parents of children with water phobia

only 1 percent out of 50 could recall a classical conditioning episode, and 58%

of the parents reported that the fear had always been present

- retrospective reports from phobic patients lack of direct conditioning in height

phobia, spider phobia (Jones and Menzies, 1995)

- separation anxiety in human infants and mammals has been found to be unrelated

to past aversive experiences of separatin (Bowlby 1973)

conclusion: learning experiences (verbal, direct, associative) are not necessary for

the development of phobias, normal childhood concerns become phobias in some

individuals by two means:

- learning to successfully avoid an object (parents used avoidant coping styles, verbal

reinforcement)

- dishabituation of childhood fears during stressful periods (Menzies & Clarke, 1993)

- genetic component: higher risk among first-degree relatives (Fyer et al. 1990)

- mixed results regarding genetic vs. environmental contribution (Bolton et al. 2006)

- genetic contribution varies to subtype – more specific genetic contribution for

blood phobia (Fyer et al. 1990)

- neuropathophysiology remains poorly understood (Fyer et al. 1998)

mixed results about amygdala hyperactivation as in other anxiety disorders

(Gossens et al. 2007)

cognitions play a role in maintainance (Rachmann 1991)

- cognitions increase arousal and likelihood of escape or avoidance (Last 1987)

empirical support:

- exposition to feared situation lead to triggering of negative self-statements, which

heighten physiological activity (Last and Blanchard 1982)

- most patients report at least one unrealistic belief about the harm that could befall

them when confronted with object or situation (Thorbe and Salkovskis 1995)

- attentional bias toward phobia related threats (Burgees 1982, Mogg et al.2004)

- Stroop paradigm: phobic individuals are slower to name the color of threat related

words (Constantine et al, 2001)