The current study aims to investigate the effect of dialectical behavioral therapy on mindfulness in patients with Borderline Personality Disorder. A treatment group will be compared to a waitlist control group.

Participants will be recruited from the Dialectical-Behavioral-Therapy (DBT) unit. DBT is a treatment approach that has been shown to be effective in the treatment of Borderline Personality Disorder. DBT integrates different psychotherapeutic interventions as well as Mindfulness Meditation exercises. Mindfulness is a meditation practice that can improve present moment awareness. When applied as therapeutic intervention mindfulness meditation can help patients to stay with their attention in the present moment, to be aware what is happening in the here and now, and to better identify and regulate upcoming emotions.

The current observational study investigates changes in symptom severity and mindfulness skills during DBT treatment. A treatment group will be compared to a waitlist control group. The two groups are predefined by routine medical care.

Symptom severity and mindfulness skills will be assessed at baseline (before treatment or when accepted for the waitlist) and after 12-weeks. A within and between group analyses will be performed.

Inclusion Criteria:

• Clinical diagnosis of Borderline Personality Disorder
• On the waitlist for DBT treatment or actually treated with DBT
• Not previously treated with DBT.

Exclusion Criteria:

• Severe psychiatric comorbidity e.g. psychosis, severe depression, suicidality

Male and female BPD Patients from 18 to 60 years.