Peripartal cognitive impairment: Secondary to depression?

Twenty pregnant women and 20 controls matched for age and IQ were tested on a range of cognitive functions at three time points: in the last month of pregnancy, 48 hours after delivery, and four weeks after delivery. Pregnant women obtained significantly lower scores on digit symbol and paced auditory serial addition tests 48 hours after delivery. There were no significant differences between the groups on logical memory, trail making or letter cancellation tasks. The degree of cognitive impairment was correlated with the severity of depression, and the differences between the pregnant and control groups in cognitive function became nonsignificant when the effect of depression was controlled. Cognitive functions related to fluid cognitive ability are impaired in the immediate post-partum period and the severity of impairment is correlated with self-reported depression.