Maternal Variables

We collected information on maternal age and socio-economic status (SES) during Phase 1, using the Geneva Socio-Demographic Questionnaire (50), which included the Largo index (51) to measure socio-economic status.

We assessed mothers for maternal IPV-PTSD using the structured interview the Clinical Administered PTSD Scale (CAPS) (52) in Phase 1. The version of the CAPS that was used included 30 items corresponding to the DSM-IV diagnosis for PTSD, and yielded a total symptom severity score. It is the gold standard in PTSD assessment, with high sensitivity (90%) and specificity (95%), as well as a Cronbach's alpha coefficient of 0.97 (53). Mothers with a score higher than 40 and/or who fulfilled DSM-IV criteria for lifetime PTSD were categorized as having a diagnosis of lifetime PTSD.

We measured maternal somatization using the somatization subscale of the widely-used Symptom Checklist-90-Revised inventory (SCL-90-R) (54, 55) during Phase 1. This instrument assesses a wide variety of psychopathological symptoms, including somatization among nine other categories of psychopathology. Each item is rated on a 5-point scale of distress (0 = never, to 4 = extremely). The total score for the somatization subscale was used for the present study, as a continuous variable. Good reliability and validity have been demonstrated for the SCL-90-R (56).

Maternal intrusive/controlling behavior was assessed in Phase 1 via the Care-Index (57–59). Coded observations were videotaped during a 5-min bout of mother-child play taken from a 25-min interaction protocol (60), with individual subscales concerning the mother and concerning the child, respectively. For the present analysis, we used data representing coded observations of maternal behavior. Specific aspects of interactions, including the mother's ability to comfort the child, the receptivity to mother-child turn-taking, shared pleasure, joint attention, non-verbal and verbal negotiation, and reciprocal communication, were rated by a coder. Seven dimensions of interactive behavior were taken into account: facial and vocal expression, position and body contact, expression of affection, turn-taking, control, and choice of activity. Three types of caregiving behaviors are assessed along continuous scales: sensitive, controlling and unresponsive caregiving behavior. The three maternal behavior scales range from 0 to 14 (for example for controlling behavior: from 0 = not being at all controlling, to 14 = being extremely controlling). Two experienced clinical psychologists independently rated the videos. Inter-rater reliability of the Care-index was excellent (ICC = 0.92), as well as of the three maternal behavior scales (ICC sensitive = 0.88; ICC controlling = 0.86; ICC unresponsive = 0.85) (61).

We additionally evaluated maternal alexithymia in Phase 1 using the French version of the Toronto Alexithymia Scale (TAS-20) (62). This is a well-validated instrument composed by 20 items resulting in three subscales, including ability to identify feelings, ability to describe feelings, and externally oriented thinking. For the present analysis, we only used the “ability to identify” scale, resulting in a continuous variable. Overall internal consistency of the TAS-20 French version was acceptable (Cronbach's alpha = 0.74) (61).