Supplementary Material for: Suspected Postpartum Depression Revealed to be CSF1R-Related Leukoencephalopathy: A Case Report

Introduction
This is a case of a 32-year-old woman who developed postpartum depression (PPD). She became anxious and depressive about caring for her child, and the Edinburgh Postnatal Depression Scale (EPDS) test showed a score of 9 at two weeks after delivery, and at 7 months postpartum, she presented with major melancholic depression followed by mild cognitive decline without any neurological symptoms except cluttering speech.
Case Presentation
Cerebral MRI showed confluent FLAIR hyperintensities in the periventricular and frontal deep white matter, with multiple spotty calcifications in the frontal white matter by cerebral CT. Genetic testing revealed a mutation in the colony stimulating factor 1 receptor (CSF1R).
Conclusion
This case report is consistent with evidence that PPD may have organic causes in some cases, including CSF1R mutations. Atypical findings such as mild cognitive decline combined with PPD in psychiatric interview may justify brain imaging to avoid misdiagnosis, since CSF1R-related leukoencephalopathy is probably an under-recognized disease in medical psychiatry. Further investigations are needed to clarify a pathophysiological correlation between CSF1R signaling abnormality and PPD as well as major depression.