Background: Numerous studies have been published on postnatal depression (PND) over the last 10 years. A controversy has arisen regarding the specificity of the diagnostic concept. It is based on 2 points: the hormonal environment and the course and recurrence of PND. EEG Sleep studies are also numerous, but this paper presents the first study on EEG sleep profile during PND.
Methods: 24 women suffering from major depression according to RDC were placed in 3 groups: 1) Group A (n = 8): PND; 2) Group B (n = 8): depression with a past history of PND; 3) Group C (n = 8): depression without a past history of PND. Women were age-matched and according to the Hamilton 24 item severity score. Group A patients were delivered within less that 6 months, groups B and C within a minimum of 3 years. None were pregnant or alcoholic, and none were physically ill.
Results: There was no difference between groups B and C. Group A was characterised by a significantly longer stage IV sleep. There was also a strong tendency to a shorter stage I sleep and a better quality of sleep (total sleep time and number of awakenings) during PND.
Discussion: Our study shows that, even if similar to major depression, specific polysomnographic alteration can be found during post-partum depression. This finding is relevant to the hypothesis of PND's diagnostic specificity. The perfect similarity between groups B and C strengthens this evidence. Nevertheless, the significance of SWS alterations are difficult to explain and additional studies are required.
Conclusion: The EEG Sleep profile during PND differs from major depression of the same severity. This appears to favour the specificity of the diagnostic concept.