What the evidence says, including where it is thin
Three studies, and the honesty in them is the point.
The first is where prolonged grief as a diagnosis comes from, and what it establishes is that persistence and impairment, rather than intensity of love, are what separate disordered grief from grief.
The second is the one this course quoted in lesson four. When the trials of formal support after perinatal death were pooled, the evidence was not sufficient to show that structured support programmes improve outcomes. We would rather show you that than tidy it away. The practical reading is not that nothing helps. It is that no package has been shown to beat honest information, decent treatment and other people who have been through it, which is why lesson four was deliberately modest.
The third is for the infertility strand. Psychological support does reduce distress, with cognitive behavioural approaches doing best. Note the authors' own caution about the pregnancy rate outcome, which is the one most likely to be overstated when this research reaches the newspapers. Reducing distress is worth having on its own terms, and this course does not claim it makes anyone conceive.
What the research says
Prigerson HG, Horowitz MJ, Jacobs SC, and others (2009). Prolonged grief disorder: psychometric validation of criteria proposed for DSM-V and ICD-11. PLoS Medicine, 6(8), e1000121 doi
Sets out the criteria that became prolonged grief disorder in the international diagnostic systems. What separates it from grief is persistence beyond a defined period together with intense yearning and impaired functioning, rather than the depth of the attachment.
Koopmans L, Wilson T, Cacciatore J, Flenady V (2013). Support for mothers, fathers and families after perinatal death. Cochrane Database of Systematic Reviews, 2013(6), CD000452 doi
The reviewers concluded that the available evidence is not sufficient to establish that formal support interventions after perinatal death improve outcomes for parents. This is a statement about what has been demonstrated, not a statement that support is useless, and it is the reason this course keeps what it offers small and modest.
Frederiksen Y, Farver-Vestergaard I, Skovgard NG, Ingerslev HJ, Zachariae R (2015). Efficacy of psychosocial interventions for psychological and pregnancy outcomes in infertile women and men: a systematic review and meta-analysis. BMJ Open, 5(1), e006592 doi
Psychosocial interventions reduced psychological distress in people experiencing infertility, with cognitive behavioural approaches performing best. The authors flag that the trials varied widely and carried risk of bias, and they are explicitly cautious about the pregnancy rate outcome.