Effects of pregnancy and delivery on serum prolyl endopeptidase (PEP) activity: alterations in serum PEP are related to increased anxiety in the early puerperium and to postpartum depression.
BACKGROUND
There is now some evidence that anxiety or anxiety disorders are related to increased activity of serum prolyl endopeptidase (PEP) and that major depression is related to lower serum PEP. The aims of the present study were to examine (i) the effects of pregnancy and delivery on serum PEP and (ii) the relationships between serum PEP and postpartum depression, anxiety in the early puerperium and a past history of depression.


METHODS
Serum PEP activity was measured in 11 healthy nonpregnant and in 98 pregnant women 3 days before delivery and 1 and 3 days after delivery. On the same occasions, pregnant females completed the Spielberger State Anxiety Inventory (STAI) and were divided into high and low anxiety responders, as defined by changes in the STAI. The presence of a previous depression and postpartum depression within 3 months of delivery was assessed by means of DSM-IV criteria.


RESULTS
Serum PEP activity was significantly higher 1 and 3 days after delivery than before. Women with a past history of depression as well as anxiety responders had significantly increased serum PEP activity over nonpregnant women and puerperae with a negative history and anxiety nonresponders, respectively. Parturients who developed a postpartum major, but not minor, depression had significantly lower serum PEP than parturients without postpartum depression. The results were controlled for maternal and labor variables, such as type of analgesia and delivery, induction of labor, breast feeding, parity, and duration of pregnancy and labor.


CONCLUSIONS
Our results show that, in puerperae, increased serum PEP is related to increased state anxiety in the early puerperium and that lowered serum PEP is related to a subsequent postpartum major depression.


CONCLUSIONS
The results suggest that increased serum PEP may be related to postpartum anxious blues and that lowered serum PEP may predispose toward postpartum major depression.
Maes
M
M
Clinical Research Center for Mental Health (CRC-MH), University Department of Psychiatry, AZ Stuivenberg, 267 Lange Beedekensstraat, 2060, Antwerp, Belgium. crc-mho@online.be
Libbrecht
I
I
Lin
A
A
Goossens
F
F
Ombelet
W
W
Stevens
K
K
Bosmans
E
E
Altamura
C
C
Cox
J
J
de Jongh
R
R
Scharpé
S
S
D000328:Adult; D000704:Analysis of Variance; D001007:Anxiety / Q000097:blood* / Q000175:diagnosis / Q000523:psychology; D036861:Delivery, Obstetric; D019052:Depression, Postpartum / Q000097:blood* / Q000175:diagnosis / Q000523:psychology; D003865:Major Depressive Disorder / Q000097:blood* / Q000175:diagnosis / Q000523:psychology; D010450:Endopeptidases / Q000097:blood*; D005260:Female; D006801:Humans; D049590:Postpartum Period / Q000097:blood* / Q000523:psychology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D013997:Time Factors
D010450:Endopeptidases