Cardiac autonomic function during sleep of never-depressed borderline subjects: a pilot study

In a controlled 48 h ambulatory polysomnographic study of never-depressed subjects with DSM-III-R borderline (BDL) personality disorder (PD) we obtained measures of tonic and phasic heart rate variability. Subjects with BDL PD showed a significantly smaller index of tonic heart rate decrease during NREM sleep than normal controls. This is unlikely to be a state-dependent finding and it may derive from relative augmentation of adrenergic function compared to cholinergic function between wakefulness and NREM sleep. Hyperadrenergic states in BDL PD have already been suggested by studies of other biological indicators: a smaller index of tonic heart rate decrease may be a further correlate of core psychobiological dimensions such as impulsivity and affective instability.