Results at the 6-month assessment revealed significant and sizable differences between the intervention and the comparison condition. These differences became more pronounced when compared with the 4- to 5-week outcomes and at the six month follow up: Davidson Trauma Scale (Cohen's d = -0.74, P < .001), Beck Anxiety Inventory (Cohen's d = -0.627, P = .001), Beck Depression Inventory II (Cohen's d = -0.638, P = .002). However, there were no differences in the effect sizes between the 6- and 9-session interventions.
The investigators concluded that a brief, 6-session intervention, based on principles of trauma-focused cognitive behavior therapy, was effective at reducing symptoms of trauma, anxiety, and depression in mothers of preterm infants. Mothers showed increased benefits at the 6-month follow-up, suggesting that they continued to make use of techniques acquired during the intervention phase. There was no added benefit from providing 3 additional sessions beyond the 6-week course.