 Fifty female patients diagnosed with BPD will undergo a year of intensive MBT that is designed to target domains of BPD pathology. The patients will be assessed at baseline and every 6 months over the treatment period. Matched healthy control subjects will be assessed at 6 month intervals to compare changes in DNA methylation, BDNF serum levels, salivary cortisol levels, and neuropsychological test performance. To link components of the neuropsychiatric mechanisms underlying the onset of illness, course, and response to treatment, patients will undergo assessment of clinical symptoms, comorbidity patterns and psychosocial impairment. Patients and control subjects will at baseline undergo assessment for childhood trauma, self-harm, suicidal behavior, early maladaptive schemas, and personality traits, and within the 1-year study period also undergo continuous assessment for changes in symptoms of dissociation, depression, and personality dysfunction. 