Acute Effects of Physical Exercise in Patients with Borderline Personality Disorder

Background: Borderline personality disorder (BPD) is one of the most common personality disorders, with a lifetime prevalence of up to 5.9% and core symptoms of emotional and behavioral dysregulation, instability in interpersonal relationships, identity disturbances, stress-related dissociation, non-suicidal self-injuries, and suicidal behavior. Treatment mainly consists of psychotherapeutic procedures, frequently supplemented by pharmacotherapy to reduce specific symptoms such as affective and cognitive dysregulation. Besides possible adverse effects from medication, both, psychotherapy and medication do not lead to a complete remission of BPD. Previous studies point towards a positive influence of physical exercise on BPD symptoms and related neurobiological processes, while to our knowledge no study has investigated the effects of exercise in patients with BPD yet.

Objectives: To investigate the effects of a single session of physical exercise on stress regulation, cognitive and emotional functioning, and associated neurophysiological processes in patients with borderline personality disorder. A further aim is to identify the optimal exercise intensity (moderate vs. high intensity).

Hypotheses: The investigatiors expect that acute exercise will enhance stress perception and cognitive and emotional functioning, which will be reflected in enhanced behavioral measures and changes on biomarker level. In addition, the investigatiors expect to gather insights regarding the optimal exercise intensity.

Methods: 60 patients with borderline personality disorder and 60 healthy controls will participate in two 30-min experimental conditions on separate days in counterbalanced order (at least 48 hours apart): in the exercise condition, half of the group will cycle on an ergometer with moderate intensity, the other half will perform a high-intensity interval training. Intensities will be calculated based on the individual maximal heart rate measured during a maximal exercise test in a pre-experimental session. In the control condition, all participants will watch a movie. Before and after each condition, they will perform a classic and an emotional version of the Stroop test, in order to assess exercise effects on impulsivity and emotion regulation. To test for exercise effects on stress-related responses, they will further participate in a Stress test 90 min following each condition. The investigatiors will collect saliva and blood samples together with state questionnaires at various study time points to test for effects on peripheral biomarkers related to stress, cognition, and BPD pathology (e.g., cortisol, alpha-amylase, serotonin metabolism, noradrenaline, BDNF).

Inclusion criteria

• estimated verbal intelligence quotient >80 (MWT-B; Lehrl 2005)
• patients: diagnosis of borderline personality disorder according to DSM-5

Exclusion criteria

• neurological disorders
• health conditions interfering with exercise safety, e.g. coronary heart disease
• visual impairments that may interfere with performance of the cognitive tasks
• endocrine disorders, e.g. hyperthyreosis or diabetes mellitus;
• following psychiatric disorders: psychosis or affective disorders with psychotic symptoms, schizophrenia, substance abuse or dependence, autism spectrum disorders, anorexia nervosa;
• healthy controls: BPD, intake of psychotropic drugs