An associative learning deficit in 1-year-old infants of depressed mothers: role of depression duration.

The effectiveness of infant-directed speech (IDS) produced by non-depressed mothers for promoting the acquisition of voice-face associations was investigated in 1-year-old children of depressed mothers in a conditioned-attention paradigm. Prior research suggested that infants of mothers with comparatively longer-duration depressive episodes exhibit poorer learning in response to non-depressed mothers' IDS, but duration of depression was confounded with infant age. In the current study, 1-year-old infants of currently depressed mothers with relatively longer-duration depressive episodes (i.e., perinatal onset) showed significantly poorer learning than 1-year-olds of currently depressed mothers with relatively shorter duration depressive episodes (non-perinatal onset). This was true despite the fact that there were no measurable differences in the severity of depression, level of social functioning, or antidepressant medication use between the two groups. These findings add support to the hypothesis that there is an experience-based change in responsiveness to female IDS in infants of depressed mothers during the first year of life.