Sleep-EEG in borderline patients without concomitant major depression: a comparison with major depressives and normal control subjects.

The link between borderline personality disorder (BPD) and the affective disorders remains controversial. The aim of this study was to examine the relationships between BPD and major depression (MD) from the perspective of sleep parameters and to contribute to the characterisation of the sleep-EEG in BPD. We compared 20 off-medication BPD in-patients without co-existing MD with 20 sex- and age-matched MD patients without BPD and 20 sex- and age-matched control subjects. BPD patients had a greater prevalence of drug or alcohol abuse and suicide attempts than MD patients. MD patients had higher scores on the Hamilton Depression Rating Scale (HDRS). Both BPD and MD patients had less total sleep time, more prolonged sleep onset latency, and a greater percentage of wakefulness than control subjects. BPD patients and control subjects had more stage 2 sleep than MD patients. BPD patients had a longer duration of rapid eye movement (REM) sleep, and less stage 3, stage 4 and slow wave sleep than MD patients and control subjects. REM latency did not differentiate the three groups. BPD and MD patients shared sleep-continuity characteristics, but sleep architecture differentiated the two groups. BPD patients with a past history of MD had more wakefulness and less slow wave sleep than BPD patients without a history of MD; other sleep parameters, age, sex and HDRS scores were not statistically different in the two BPD subgroups. Although BPD and MD may coexist, the present study offers more arguments favouring the concept that they are not biologically linked and that BPD patients with depressive symptoms often experience an affective syndrome different from that in MD patients without BPD, in terms of quality and duration of symptoms and of the biological substrate.