[Recurrent depressive disorder associated with an atypical CADASIL syndrome]

A 55-year-old man with recurrent depressive episodes, with onset at age 45, was admitted to hospital after a suicide attempt. Due to a recent stroke as well as a family history of stroke and depression, CADASIL (prevalence of 2-5 per 100.000) was considered as a possible diagnosis. Although depression is common in CADASIL, the initial presentation is not typically comprised of recurrent depressions. Brain MRI, however, did not show the characteristic white matter lesions in the anterior temporal lobe. Genetic analysis revealed a cysteine-sparing mutation (Arg61Trp) in the NOTCH3 gene. Recently, several such mutations have been associated with CADASIL presenting with an atypical phenotype including a lower prevalence of recurrent stroke. This suggests that the prevalence of CADASIL may be higher than estimated in depressed patients. This case demonstrates the importance of considering CADASIL as a possible etiology of depression as this has consequences for prognosis, treatment and genetic counseling.