Quetiapine is a newer (atypical) anti-psychotic mainly used to treat schizophrenia and bipolar disorder. Some small studies have shown it to be effective in treating borderline personality disorder (BPD) but the research on this is limited. A Belgian study of 41 patients with BPD were given quetiapine over a period of 12 weeks and given a range of psychological tests. By the end of the study the participants' scores for impulsivity, hostility, affective lability (sudden changes of mood), depression, anxiety and anger had all decreased significantly.
Eynde, Frederique Van den ... [et al] - Efficacy of quetiapine for impulsivity and affective symptoms in borderline personality disorder Journal of Clinical Psychopharmacology April 2008, 28(2), 147-155