Date of Degree
PhD (Doctor of Philosophy)
Michael W. O'Hara
A large body of evidence has accumulated which indicates that infants of postpartum depressed mothers are at risk for negative sequelae including later psychopathology. However, methodological difficulties including discordant definitions of postpartum depression and the use of paradigms which used the mother-infant relationship to assess infant emotional expression and regulation have decreased the ability to reach a consensus regarding the nature and transmission of that risk. This study sought to address those methodological difficulties by employing an established paradigm designed to elicit emotionality in infants, the Laboratory Temperament Assessment Battery (Lab-TAB; Goldsmith & Rothbart, 1999).
Participants were 30 women who met DSM-IV criteria for Major Depressive Disorder (MDD), 50 women who did not meet MDD criteria, and their 8-13 month old infants. The women were recruited from five counties within Iowa which contain both rural and urban centers. Consistent with state demographics the sample was predominantly Caucasian (76%). Mother-infant dyads were assessed approximately five months after the mother had completed a diagnostic interview. At that time six episodes from the Lab-TAB designed to elicit fear, anger, and positive affect were conducted.
Emotional reactivity was coded used the AFFEX (Goldsmith & Rothbart, 1988) and composite scores were generated for each emotion. Infants of depressed mothers exhibited less intense pleasure to stimuli designed to elicit that emotion. There was also a slight, non-significant, trend for infants of depressed mothers to display more intense fear and to remain fearful longer. There was not a difference between the groups in anger expression. Emotional regulation was examined using a set of procedures set-forth by Buss and Goldsmith (1998) to determine effective regulation. These procedures involve calculating the change in affect from the coding epoch in which a "putative regulatory behavior" is displayed to the epoch immediately after the behavior. Change scores which involved no change in affect or a decrease in negative affect were considered effective regulation. Playing with clothing or an object and interacting with the stimulus were effective at regulating both fear and anger. In addition, averting gaze (disengaging with the task) was effective in regulating anger. Follow-up analysis revealed that infants of depressed mothers used gaze aversion more frequently than infants of nondepressed mothers. In addition, they were less likely to engage in social referencing (looking toward the mother) during episodes designed to elicit fear.
The findings of this study are consistent with a growing body of evidence which documents the significance of considering low positive affect in examination of diagnosis and risk for depression and suggests that fear expression may be central to anxiety. Furthermore, results from the emotional regulation paradigms underscore the need for continued examination of the construct of "effective regulation." In addition, these results highlight disruptions in the mother-infant relationship which have implications for developing efficient regulatory mechanisms.
Copyright 2009 Christina Louise Franklin