A momentary assessment study of the reputed emotional phenotype associated with borderline personality disorder

Stress is postulated to play an essential role in the expression of core borderline symptoms. However, the phenomenology of stress reactivity in borderline personality disorder remains unclear. The current study investigated the phenomenology of stress sensitivity in borderline personality disorder in the flow of daily life and compared this with stress sensitivity in patients suffering from psychotic disorders, a group so far known to report the largest reactivity to stress.

A total of 44 borderline patients, 42 patients with psychotic disorder and 49 healthy controls were studied with the Experience Sampling Method (a structured diary technique assessing current context and mood in daily life) to assess: (1) appraised subjective stress related to daily events and activities; and (2) emotional reactivity conceptualized as changes in positive and negative affect.

Multilevel regression analysis revealed that subjects with borderline personality disorder experienced significantly more emotional reactivity to daily life stress compared with both patients with psychosis and healthy controls, as evidenced by a larger increase in negative affect and a larger decrease in positive affect following stress.

These results are the first to ecologically validate the incorporation of stress reactive symptoms in the diagnosis of borderline personality disorder. Borderline patients continually react stronger than patients with psychosis and healthy controls to small disturbances that continually happen in the natural flow of everyday life. Altered emotional stress reactivity may define borderline personality disorder.