Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a relatively common inherited arterial smooth muscle cell disease. The genetic defect is localized to the notch homolog protein 3 (NOTCH3) gene on chromosome 19q12 and is due to a missense variant in NOTCH3. The main clinical manifestations are transient ischemic attacks and repeated stroke, with cognitive impairments leading to dementia, migraine with aura, and mental/emotional disorders. To date, there is no specific therapeutic option, with only symptomatic supportive treatment for the symptoms of acute stroke, migraine, dementia, and mental abnormalities. Here, we provide a case report of a Chinese patient with CADASIL and a mutation in exon 4 of the NOTCH3 gene (p.Arg133Cys). The patient mainly exhibited recurrent cerebral infarction and affective disorder. Antidepressant treatment combined with repetitive transcranial magnetic stimulation significantly improved the depressive symptoms of the patient.