Study 1
Lieberman and colleagues (2005) employed a randomized clinical trial to examine the efficacy of Child–Parent Psychotherapy (CPP) to alleviate traumatic stress symptoms and behavior problems of children exposed to marital violence. The sample of 39 girls, 36 boys, and their mothers (75 child-parent dyads) were referred for treatment because of clinical concerns after the child witnessed or overheard marital violence. Children and mothers were eligible for the study if 1) the child was 3 to 5 years old, 2) marital violence was confirmed by the mother’s report on the Conflict Tactics Scale 2, and 3) the person perpetrating the abuse (who was usually the father figure) was not living in the home. Exclusionary criteria for participating mothers included documented abuse of the target child; current substance abuse and homelessness; mental retardation; and psychosis. Children with mental retardation and autistic spectrum disorder were also ineligible. After mothers provided informed consent, the mother–child dyads were randomly assigned to either the CPP treatment group (n = 36) or a comparison group (n = 29) that received monthly case management plus referrals for individual treatment in the community for both mother and child.
The sample of children was 37.7 percent mixed ethnicity (mostly Latino/white), 28.0 percent Latino, 14.7 percent African American, 9.3 percent white, 6.7 percent Asian, and 3.6 percent of another ethnicity. The sample of mothers was 37.3 percent Latina, 24 percent white, 14.7 percent African American, 10.7 percent Asian, and the rest were of mixed ethnicity. There were no statistically significant differences between treatment and comparison groups on demographic variables (i.e. ethnicity, income) , dependent variables (i.e. child functioning, maternal symptoms), or trauma exposure at intake.
Mothers and children were assessed at intake, 6 months into treatment, and at the conclusion of treatment (posttreatment). Measures of child symptomatology and functioning included the following:
- Children’s Exposure to Community Violence: Parent Report Version, which assesses children’s exposure to 16 forms of community violence and violence-related activities (completed by the mother).
- Child Behavior Checklist (CBCL 2/3 and 4/18), which includes the Total Behavior Problems score that measures parent reported stress-related behavior not represented in the internalizing and externalizing scales (e.g., staring into space, refusing to eat, destroying his or her own things).
- Semistructured Interview for Diagnostic Classification DC: 0–3 for Clinicians, which was administered to the mothers and used a standardized format to systematize the traumatic stress disorder (TSD) diagnostic criteria of the Diagnostic Classification Manual for Mental Health and Developmental Disorders of Infancy and Early Childhood.
Measures of maternal symptomatology included the following:
- Life Stressor Checklist—Revised, which inquired about the mothers’ lifetime incidences of very distressing events, including specific stressors more prevalent among women.
- Symptoms Checklist–90—Revised (SCL–90–R), which measured current psychiatric symptoms using a 90-item checklist. The Global Severity Index was also used to assess maternal functioning and current levels of maternal distress.
- Clinician-Administered PTSD Scale (CAPS), which is a semistructured interview that provided a PTSD diagnosis and total intensity and frequency scores for re-experiencing, avoidance, and hyperarousal symptoms.
The study authors used a general linear model repeated-measures procedure for each dependent variable, comparing the CPP group with the comparison group as the between-subject variable, and using time (intake versus posttreatment as the within-subject variable. Cases that had any missing data were deleted listwise for each analysis. The original sample of 75 dyads was included in the intent-to-treat (ITT) analysis. The study authors did not conduct subgroup analyses.
Study 2
Lieberman and colleagues (2006) conducted a randomized controlled trial using children and their mothers from the original CPP evaluation in Study 1 (Lieberman et al. 2005). In this study, participating mother-child dyads were followed 6 months after the end of treatment (i.e., the dyads were followed for 6 months longer than in Study 1). This study included 22 girls and 28 boys ages 3 to 6 years. Mothers and children at the 6-month follow up were demographically the same as described in Study 1 (Lieberman et al. 2005). Dyads lost to attrition at the 6-month follow up did not differ from those who completed the 6-month posttreatment assessment on the outcome variables of child gender, ethnicity, income, or maternal education. The one exception was that the mothers who did not complete the posttreatment assessment typically had younger children. However, at the 6-month follow up, there was a statistically significant difference between treatment and comparison groups in child gender, with the treatment group comprising fewer boys than the comparison group (30 percent versus 61 percent, respectively).
ITT analyses were conducted using a last observation carried forward (LOCF) method, in which the score at the most recent time period (intake, 6-month, or posttreatment) was substituted for later incomplete data points. The original 75 dyads are included in the ITT analyses.
Outcomes of interest were child functioning and maternal symptoms at the 6-month posttreatment follow up. Child functioning was measured using the Child Behavior Checklist (CBCL 2/3 and 4/18), which included the Total Behavior Problems score that measured stress-related behavior that was not represented in the Internalizing and Externalizing Scales. The maternal symptoms outcome was measured through the Symptoms Checklist, Revised (SCL-90–R), as described in Study 1. The Global Severity Index was also used to assess maternal functioning because it is considered a reliable indicator of current maternal distress. The study authors used a general linear model (GLM) repeated-measures procedure for each dependent variable, comparing the CPP group with the comparison group as the between-subject variable, and using time (intake versus 6-month follow up) as the within-subject variable. The study authors did not conduct subgroup analyses.
Study 3
Ippen and colleagues (2011) conducted a randomized controlled trial, using the same mother-child dyads as in the CPP evaluations in the previous studies (Lieberman et al. 2006; 2005). This study examined whether CPP was efficacious for children in early childhood who have experienced multiple traumatic and stressful events (TSEs).
The sample of intent-to-treat participants included the 39 girls and 36 boys, ages 3 to 5 years, and their mothers from the original evaluation, 6 months after the end of treatment (i.e., the same follow-up period as in Study 2). Mothers and children in this study were demographically the same as those described in Study 1 (Lieberman et al. 2005). Of the children, 12 percent had experienced two TSEs, 41.3 percent had experienced three TSEs, and 46.7 percent had experienced four or more TSEs. TSEs were calculated by summing across the following eight categories that correspond with Adverse Child Experiences (ACEs): 1) physical abuse, 2) sexual abuse, 3) witnessing domestic violence, 4) neglect, 5) separation from a caregiver, 6) caregiver criminal history, 7) caregiver substance abuse, and 8) caregiver mental illness. There were no statistically significant differences between treatment and comparison groups in posttest completion or follow up for any of the outcome variables; however, children who dropped out of the study were generally older.
Treatment and comparison group dyads were assessed at intake, posttest (12 months after intake), and at a 6-month follow up after posttest. Outcomes of interest were child depression, child co-occurring diagnoses, and maternal PTSD and depression, which were examined at the 6-month follow up between the treatment and comparison groups. Child symptomatology, including PTSD, depression, and the number of co-occurring diagnoses (i.e., anxiety, sleep disorders), was measured using the Semistructured Interview for Diagnostic Classification DC: 0-3. Maternal symptomatology was measured using the Clinician-Administered PTSD Scale (CAPS).
Data were retrieved from family history interviews; Department of Human Services (DHS) report; diagnostic interviews with mothers; and the 51-item questionnaire, Screening Survey of Children’s Exposure to Community Violence: Parent Report Version. Due to the study inclusion criteria that specified that the father figure perpetrating marital violence no longer reside in the home, all children had experienced a major separation from their biological fathers. Thus, this TSE was coded only if reports indicated that the child had witnessed at least one domestic violence event. The study authors used general linear model (GLM) repeated-measures analyses to investigate differences between the treatment and comparison groups for the outcomes of interest, except for maternal and child PTSD symptoms data that were examined through a chi-square analysis. Subgroup analyses were conducted to determine treatment effects by the level of child TSE exposure (< 4 versus 4+) and child TSE status (low- versus high-risk).