Sexual Abuse Longitudinal Study Summary (August, 2006)
Eighty four females were referred by child protective service agencies within six months after the disclosure of childhood sexual abuse along with 82 non-abused matched comparison females. This relatively large and racially diverse sample was interviewed three times in childhood (approximately once per year for three consecutive years), twice in adolescence, and most recently, when the sample is embarking on the tasks of young-adulthood (i.e., emancipation from parents, formation of identity, romantic partner selection, reproductive decisions, initiation of career, transition to motherhood). Findings from this longitudinal study have provided some of the most definitive evidence for the unique ways in which childhood sexual abuse impacts on the bio-psych-social development of females across distinct developmental stages.Approximately 45 peer-reviewed journal articles have been generated from this longitudinal study reporting on a host of behavioral, psychological, and physiological effects in both childhood and adolescence. In general, results from our study show that there are striking differences between sexual abuse victims and girls on a “normal” developmental course when taking into account possible confounds. While there are several identifiers of resilience in the lives of these women, there is also disturbing evidence that survivors of childhood sexual abuse continue to suffer throughout development. This suffering may manifest acutely, in childhood, immediately following the disclosure of abuse, or may emerge or be revisited later in life as developmentally salient issues reminiscent of the abuse surface or resurface.
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Findings by Developmental Stage
Analyses done in childhood suggest that sexual abuse victims have lower social competence, lower academic performance, and higher school avoidant behaviors then their peers. Victims are also more depressed, more dissociative, exhibit more sexual acting-out behaviors, and have lower self-esteem. Behavior problems in this period included higher rates of delinquency, immaturity, and aggressivity or bullying. Overall there is less family cohesion and a greater level of depression in their own mother (47% of whom report also being sexually abused in childhood!). Sexually abused victims are also less healthy physiologically with higher rates of obesity and evidence for some hormonal disruption.
Later in childhood and in early adolescence our findings not only show that many of these problems persist, but many new problems begin to emerge. There are still higher levels of depression, dissociative symptoms, immaturity, aggressivity, and obesity, but abuse victims at this stage of development are also exhibiting higher PTSD symptoms, lower IQ scores, greater hormonal disruption, and report younger ages of voluntary intercourse than do their same-aged peers. An evaluation of pubertal staging has indicated that, on average, females in the abused group matured at a rate of approximately 7.5 months faster for breast development and 6 months faster for pubic hair development. Rapid pubertal development may contribute to psychosocial maladjustment and exacerbate an already-turbulent development. We note that this finding may be indicative bi-directional causality in that early development of secondary sexual characteristics may increase the probability of a child becoming a victim as well as accelerate pubertal transition.
Effects later in adolescence and early adulthood suggest that the types of problems exhibited by sexual abuse victims go beyond those of the simple behavior problems or poor psychological adjustment detected in childhood and become increasingly indicative of patterns of revictimization and disturbed sexuality. Our analyses, based on an impressive retention rate of over 96%, show that abuse victims in this stage exhibit persisting depression and PTSD symptoms, but are now reporting pathological levels of dissociative symptoms. Physiologically, there are still problems with obesity (42% versus 27%), but victims are also reporting more sleep disturbances, have more gastrointestinal complaints, and poorer overall health and healthcare utilization. Cognitively, abused females were shown to have delayed receptive language acquisition and were less likely to have graduated high school. Sexual abuse victims report twice as many subsequent rapes or sexual assaults, almost twice as many physical affronts or domestic violence episodes, four times as many self-harm events or suicide attempts, and over 20% more subsequent significant lifetime traumas as compared to their same-aged peers. Sexual abuse victims also report more sexual preoccupation, lower birth control efficacy, younger ages at the birth of first children, and report having children by different men at a greater rate than their same-age peers. Abused females also reported significantly higher rates of teen pregnancy (39% versus 15%) and teen motherhood (29% versus 4%) than comparison females.
Given emerging theory that maltreated and deprived children might exhibit inordinately high catecholamine and cortisol activity as a response to chronic stress, a chief Aim of our study was to provide solid prospective evidence for HPA axis impairment in our sample of sexually abused females. Several years after the disclosure of abuse, a subsample of subjects was given ovine CRH stimulation (oCRH) in order to ascertain HPA axis regulatory systems. Results indicated that abused and comparison females showed similar basal and overall stimulated plasma cortisol levels, but that abused girls showed significantly reduced total ACTH responses to oCRH stimulation. This attenuated plasma ACTH with corresponding robust plasma cortisol responses to oCRH stimulation provided some of the first evidence for a breakdown in the regulatory HPA system for abused children.
Later in development, salivary cortisol responses to a stress induction revealed an overall pre-post stressor effect in a random effects HLM model and markedly different reactivity patterns for females with different types of abuse. Controlling for trait anxiety, within-group analyses revealed distinct cortisol reactivity patterns based on the severity of abuse. Reactivity patterns for females abused by Multiple Perpetrators (MP) accompanied by physical violence were characterized by heightened reactivity. Biological Father (BF) incest was associated with patterns indicative of marked hypo-reactivity. Those experiencing less severe forms of abuse displayed by a Single Perpetrator (SP) who was not a biological father reactivity patterns similar to the comparison group.
Our most recent analyses of Time 6 cortisol data revealed that smokers displayed a significantly attenuated diurnal decline and were also markedly hypo-reactive to a stressor as compared to nonsmokers. This is consistent with recent research suggesting how smoking interacts with the HPA axis. After controlling for abuse severity, this reactivity attenuation was even more pronounced in abused females suggesting that the smoking effects on the HPA may be exacerbate by an already-compromised HPA, thus rendering abused females more vulnerable to the effects of smoking (e.g., they may initiate smoking as a way to regulate physiological stress and/or may have an exceptional difficulty quitting).
Utilizing data from all 6 times points, basal (resting) cortisol levels were arrayed across development from age 6 to age 32 providing some of the first developmental curves of cortisol for females. These preliminary HLM analyses controlling for diurnal decline show that a quadratic function fits the data similarly for all subjects (ie., basal cortisol rises steadily throughout childhood and adolescence and peaks in early adulthood), but reveal a group X linear slope effect suggesting marked differences in linear trends. Childhood and early adolescence (the acute phases of recovery) is, on average, marked by heightened basal cortisol for abused females. However, later in development, abused females, on average, begin to appear markedly hypocortisolistic. These results suggest that abused individuals with initial chronic hyperarousal may develop a diminished capacity to sustain cortisol hypersecretion and, in order to avoid allostatic overload, adapt to a compensatory downward regulation of the HPA system resulting in attenuated cortisol secretion.
Well-being of offspring
We have also begun to evaluate the well-being of offspring born during the course of the study. Offspring whose parents experienced childhood abuse are not only at increased risk of being abused or neglected, they are also at risk for deleterious consequences of having a caregiver who suffers from significant emotional, psychiatric, and health problems. Descriptive results from our prospective, multigenerational study indicate that offspring born to mothers with histories of sexual abuse were more likely to be born preterm, have a teenage mom, and be involved in protective services than were comparison offspring. Abused mothers were also more likely to be high-school dropouts, be obese, and have experienced psychiatric problems, substance and alcohol dependence, and domestic violence.