Briefly outline and evaluate the use of Systematic Desensitisation compared to flooding as a Behavioural approach to treating phobias.

Systematic desensitisation is a method of treating phobias by gradually increasing exposure to the phobic stimulus. This is very different to the method of flooding which is instantly and explicitly exposes the patient 'neck deep'.
Systematic desensitisation is based on classical conditiong a Pavlovian method in which it is believed that all behaviour is a learned response; in SD the aim is for the patient to unlearn the behavioural response to their phobic stimulus. It is essential for the patient to be in a state of relaxation when being exposed to stimulus.An example of SD for a patient afraid of snakes would be for the therapist to make sure the patient is completely relaxed, then introduce a picture of a snake, after this a toy snake, then a small live snake in a glass box. Finally by the end of the treatment, the patient should hopefully be holding a snake.
A strength of this approach is that it is the preffered method for many patients, as in comparison to the method of flooding, it is less anxiety provoking. Additionally SD can be done by the patient themselves or even continued after treatment although it is advised to see a therapist if their phobic response returns/persists.A limitation of SD however is that it is more time consuming and costly for those patients who need multiple sessions. This could potentially exclude patients who are unable to afford this.