systematic desensitisation: uses counterconditioning to replace fear with relaxation, work out a hierachy of phobic situations from least to most frightening. Work through hierachy in a systematic way until patient experiences no anxiety when faced with the most feared scene. in vivo SD - patient gradually exposed to phobic stimulus, in vitro SD - imagining it or using pictures.
flooding: involves a single exposure to the most feared situations. Patient exposed to actual phobic stimulus or to a virtual reality version all in one session until anxiety disappears. Fear response eventually extinguished as adrenaline levels naturally decrease.
supporting evidence SD, Jones - used SD to eradicate 'Little Peter's' phobia of whitefluffy objects and animals. Rabbits presented at closer levels and his anxiety subsided. Peter rewarded with food to develop a positive correlation towards rabbit, developed affection for it and similar objects.
advantage, unlike drug therapy no sideeffects, no risk of addiction or dependency.
risk of symptom substitution, SD only deals with symptoms and not the root cause , risk that symptoms will resurface possibly in another phobia/ disorder.
time consuming
in vitro less effective, some individuals lack the ability to imagine the feared situation so might still experience a fear response when they confront the actual object or situation.