The purpose of this study is to determine whether a short term programme with internet research on the frequency of skin exchange and guided imagery modification is effective in the treatment of the feeling of being contaminated in female victims of childhood sexual abuse (CSA).

In the first session the women who suffer from a feeling of being contaminated after childhood sexual abuse are interviewed with the Structured Clinical Interview for DSM-IV (SCID) to ensure the clinical diagnosis of posttraumatic stress disorder and exclude women who meet the exclusion criteria. They get questionnaires and protocol sheets to fill out until the intervention session after a week. Afterwards the women are randomly assigned to an intervention group or a waitlist control group. During the intervention session the women in the intervention group research via internet how many times their skin cells in different regions of their body have exchanged since the sexual abuse to get the information that their skin has changed hundreds and hundreds of times and has nothing in common with their skin in childhood or adolescence. This first part of the intervention is based on a component of the DBT-PTSD. Afterwards the therapist guides an imagery modification. The women imagine the feeling of being contaminated and then to peel off their former contaminated skin and the maturing of hundreds of new clean skin cells to process the rational information of the internet research emotionally. At the end of the intervention session patients get a tape with the guided imagery instruction and commit to listen to the tape daily to exercise the guided imagery modification until the third session after a week. In the last session the homework is discussed and information on posttraumatic stress disorder and psychotherapeutic treatments of posttraumatic stress disorder is offered.Women in the waitlist control group get the same treatment as the women in the intervention group after a period of five weeks.

Inclusion Criteria:

• Sexual abuse in childhood or adolescence
• Feeling of being contaminated
• Clinical diagnosis of posttraumatic stress disorder concerning the trauma of sexual abuse in childhood or adolescence according to DSM-IV
• Informed consent

Exclusion Criteria:

• Currently in psychotherapy
• Life time clinical diagnosis of schizophrenia, schizoaffective disorder or bipolar disorder according to DSM-IV
• Body mass index < 16,5
• Endangerment of self or others
• Clinical diagnosis of alcohol or drug addiction according to DSM-IV
• Mental retardation