RESUMO
BACKGROUND: Major depressive disorder (MDD) and borderline personality disorder (BPD) are highly prevalent and often comorbid psychiatric conditions, with abnormal processing of negative affect resulting from psychological stress. Characteristics of central processing of autonomic response to stress in each disorder are not clearly settled. METHODS: We obtained whole brain 3T fMRI with concurrent skin conductance, respiration rate, and heart rate variability measures in a cohort of MDD (N=19), BPD (N=19) patients, and healthy (N=20) individuals. Experiments were conducted in resting conditions, during a control mental arithmetic task, during highly stressful mental arithmetic, and in the period immediately following psychological stress. RESULTS: Widespread activation of central autonomic network (CAN) structures was observed during stress compared to a control task in the group of healthy participants, whereas CAN activation during stress was less intense in both BPD and MDD. Both patient groups displayed increased sympathetic and decreased parasympathetic activation compared to healthy subjects, as previously reported. The relationship between peripheral sympathetic or parasympathetic activity and simultaneous regional brain BOLD activity was similar in BPD patients and healthy subjects, and markedly different from that seen in MDD patients. LIMITATIONS: The sample size, the fact it belonged to a single study site, and low grade affective symptomatology in both patient groups limit the generalizability of the present findings. CONCLUSIONS: The diverging neurobiological signature in the homeostatic response to stress in MDD and BPD possibly represents a heuristically valuable candidate biomarker to help discern MDD and BPD patients.
