Children of depressed persons

Prior research on neurophysiology of infants of depressed mothers commonly has focused on EEG power and asymmetry. Whether infants of depressed mothers show differences in coherence is undetermined. This study examined the development of EEG alpha coherence in infants of mothers with various degrees of depression. Also investigated was the normative development of alpha coherence in infancy. The relationship between maternal depression and infant coherence was analyzed at different infant ages, from 1-12-months-old. There were significant effects of maternal depression on infant coherence between frontal-occipital regions, frontal-parietal regions, and central-parietal regions, in 1-month-olds. There were also significant maternal depression effects in central-parietal coherence in 1-3-month-olds and 3-6-month-olds. Differences were in the right hemisphere and were generally characterized by lower coherence in infants whose mothers had higher depression. Infants whose mothers had lower depression demonstrated age-related decreases in coherence, but infants of more highly depressed mothers did not show age-related differences.

EEG was examined in 348 1-week, 1-month and 3-month-old infants of depressed and non-depressed mothers. Both the percentage of infants exhibiting spectral peaks and the frequency in Hz at which those peaks were exhibited increased with age. Similarly, the EEG spectra showed a developmental increase in absolute power and a decrease in lower frequency and increase in higher frequency components. Infants of depressed mothers exhibited greater 8Hz lower 3Hz relative power and greater left frontal EEG log-absolute power than infants of non-depressed mothers. This profile was specially marked across a narrow frequency range which shifted from 3--9Hz to 4--9Hz by 3-months. Evaluation of 4 different asymmetry indices revealed that while both the log-absolute difference and the absolute ratio asymmetry indices best differentiated infants of depressed from infants of non-depressed mothers, the absolute ratio asymmetry index appeared to minimize within group variability. The significance of these findings are discussed.