Self injurious behavior (SIB) is a core feature of borderline personality disorder (BPD). BPD is a potentially life threatening psychiatric disorder causing considerable intraindividual distress, impairment of psychosocial functioning, disturbed relationships and high rates of treatment utilization. The use of antipsychotics in BPD implies differential etiopathogenetic thinking in specialists who are convinced that BPD is a heterogen diagnosis representing "borderline schizophrenia" or bipolar disorder. Quetiapine decreases psychotic symptoms in hallucinating BPD and may be effective in "borderline schizophrenia" or "borderline bipolar patients". Several articles have speculated on the effectiveness of quetiapine in borderline symptoms as SIB targeting on reduction of causal pervasive affective dysregulation.

A 24 years old female patient was referred to a psychiatric inpatient unit due to an increase of SIB. Initial diagnostic process solidified diagnosis of BPD. Axis I diagnosis were alcohol abuse, recurrent major depression, eating disorder nos. A protocol on inner tension and frequency of SIB was introduced. HAM-D, CGI-S, CGI-I and Barrat-Impulsiveness-Scale were administered weekly respectively monthly for 3 month. After informed consent the initial polypharmacy excluding the antidepressant was terminated within the following 10 days and quetiapine was started with 25mg/day. The following days quetiapine dosage was titrated to 250mg/day with only mild sedation. There was a marked decrease of SIB over 3 month of treatment. All other measures improved over 3 month of observation time. Decrease of symptom pressure activated the patient to increase use of solving skills to reduce/control inner tension.