What is the main summary and theory of this journal article? Primary Care Screening for and Treatment of Depression in Pregnant and Postpartum Women Evidence Report and Systematic Review for the US Preventive Services Task Force

The purpose of the study was to review the efficacy of depression screening and treatment for pregnant and postpartum women and to access the accuracy of specific screening instruments.
To realize the objectives of the study, two independent investigators reviewed fair and high quality studies from sources such as government websites, MEDLINE, PubMed, PsycINFO, and the Cochrane Collaboration Registry of Controlled Trials through January 20, 2015. Investigators also assessed the benefits of cognitive behavioral therapy (CBT) for depressed pregnant and postpartum women.
The investigators created summary tables to document key questions (KQ) and their conclusions.
For the advantages and disadvantages of depression screening (KQ1, KQ3), the investigators studied randomized or non-randomized clinical trials conducted in primary care settings. For diagnostic accuracy (KQ2), they examined studies of the Patient Health Questionnaire (PHQ) or Edinburgh Postnatal Depression Scale (EPDS) compared to structured or semi-structured diagnostic interviews with a trained interviewer or mental health clinician.
For the benefits of antidepressants and behavioral-based treatments (KQ4), the investigators included trials that had a minimum of six weeks of follow-up. For the harms of treatment (KQ5 and KQ5b), they examined randomized or non-randomized clinical trials, large comparative observational studies, and systematic reviews.
Here are the study results:
1) 6 trials showed 18% to 59% relative reductions with screening programs and 2.1% to 9.1% absolute reductions in the risk of depression at follow-up (3-5 months). Thus, screening programs (with additional treatment supports such as those provided by specially trained depression care clinicians) were seen to reduce symptoms of depression in pregnant and postpartum women.
2) 23 studies showed sensitivity ranging from 0.67 (95% CI, 0.18-0.96) to 1.00 (95% CI, 0.67-1.00), and specificity was consistently 0.87 or higher on the Edinburgh Postnatal Depression Scale. The screening instruments used were the Patient Health Questionnaire (PHQ) or Edinburgh Postnatal Depression Scale (EPDS). Both were shown to be effective in identifying pregnant and postpartum women who required further evaluation and treatment for depression.
3) Gestational second-generation antidepressant use may result in a slightly increased risk for potentially serious maternal and infant harms. Maternal harms included preeclampsia, suicidality, seizures, bleeding, and miscarriage. Infant harms included major malformations, low birth weight, neonatal respiratory distress, seizures, and neonatal death.
4) Clinically-depressed pregnant and postpartum women who were treated with CBT showed an increase in the likelihood of remission.