Neuronale Manifestationen nach sexuellem Kindesmissbrauch: Klinische Bedeutung für Erwachsene mit Symptomen der Anhedonie
Zusammenfassung der Projektergebnisse
Based on the US Department of Health and Human Services, in 2008, over 69,000 children experienced childhood sexual abuse (CSA) in the US alone. While CSA sequelae can be heterogeneous, affective disorders and maladaptive behavior (i.e., selfharm, unsafe sexualized behavior, substance abuse) are among the most common outcomes following CSA. Although neurobiological studies have confirmed the impact of chronic stress on neuroplasticity of the developing brain (including the anterior cingulate cortex (ACC)), research studies on neural correlates of maladaptive behavior are limited. The present study investigated if behavioral and electrophysiological indices of disrupted reinforcement learning were associated with higher engagement in maladaptive behavior following CSA. It was hypothesized that women who experienced CSA (1) would demonstrate blunted reward learning, (2) abnormal electrophysiological responses to reward processing, (3) an increased activation in affective subdivisions of the ACC (BA 25, 24). Finally, (4) deficits in reward learning were hypothesized to correlate with higher use of maladaptive behavior. The final sample consisted of three groups: women with a history of CSA that occurred between the ages of 7-12 years and a diagnosis of remitted major depressive disorder (CSA; n=15), women with remitted depressive disorder but no CSA (rMDD; n=16) and healthy controls with no history of psychopathology or childhood trauma (n=18). Participants took part in a two-session study in which they first completed a clinical and trauma assessment followed by an EEG recording using a reinforcement learning paradigm. In line with our hypotheses, women in the CSA group showed greater difficulties in learning from previously rewarded but not previously punished information, compared to women with a history of MDD but no CSA and healthy controls (Hypothesis 1). Relative to rMDD and controls, women in CSA group showed smaller differentiation of event-related potentials following correct and incorrect trials on reward learning trials but on punishment learning trials, thus confirming Hypothesis 2. Moreover, CSA group showed increased activation in affective (i.e., subgenual and rostral) subdivisions of the ACC on reward learning trials compared to controls and rMDD groups. No group differences in ACC activation emerged on punishment trials. Finally, relative to rMDD and controls, women with a history of CSA engaged more frequently in maladaptive behaviors including violence-related behavior, suicidal ideation/attempts, self-harm, unsafe sexualized behavior, and dysfunctional eating. Highlighting the clinical relevance of these findings, accuracy on trials that require reward-based decision making was negatively correlated with engagement in maladaptive behaviors including perpetrating violence in past 12 months (Hypothesis 4). No correlation was found between accuracy on trials that required learning from punishment and maladaptive behaviors. Collectively, data deriving from behavioral, scalp and brain level suggest that women with a history of CSA show deficits in reward learning, in particular when needing to integrate previously learned reward contingencies to optimize decision making. Although more research is needed, to date, findings suggest that disrupted positive reinforcement learning in women with CSA histories may contribute to their more frequent engagement in maladaptive or high-risk behaviors.
Projektbezogene Publikationen (Auswahl)
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(2008). Sexual abuse and mental injury: Practice guidelines for Aotearoa New Zealand: Practice guide. Wellington, New Zealand: Accident Compensation Corporation
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(2008). Sexual abuse and mental injury: Practice guidelines for Aotearoa New Zealand: Principles and recommendations. Wellington, New Zealand: Accident Compensation Corporation
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(2011). Conceptualization of the complex outcomes of sexual abuse: A signal detection analysis. Journal of Child Sexual Abuse. 20, 677-694
Pechtel, P., Evans, I. M., & Podd, J. V.
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(2011). Effects of early life stress on cognitive and affective function: An integrated review of human literature. Psychopharmacology, 214, 55-70
Pechtel, P. & Pizzagalli, D.A.
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(2011). Perceived parental protection and cortisol responses among young females with borderline personality disorder. Psychiatric Research, 189, 426-432
Lyons-Ruth, K., Choi-Kain, L., Pechtel, P., Bertha, E., & Gunderson, J.
