Major Depressive Disorder Complicated with Spinocerebellar Ataxia: Report of 2 Cases

BACKGROUND: It is known that patients with spinocerebellar ataxia (SCA) tend to exhibit depressive symptoms. But the pathology of depressive symptoms complicated with SCA, including the reaction to the stress resulting from decreased motor function and central dysfunction due to neurodegeneration, is controversial and remains to be elucidated. To our knowledge, there have been hardly any reports on treatment methods of major depressive disorder (MDD) complicated with SCA. Case Reports: We report 2 cases in which selective serotonin reuptake inhibitors (SSRIs) were effective against MDD complicated with SCA. Interestingly, one of the patients developed the symptoms of spinocerebellar degeneration (SCD) during the course of the MDD, and the other patient developed the symptoms of MDD during the course of SCA, but complete remission of the MDD occurred in both cases. In our cases, the depressive symptoms may have been caused mainly by an abnormality of reversible neural transmission including serotonin transmission due to central dysfunction, and there is the unlikely possibility that the depressive symptoms are reactive to the stress due to decreased motor function, because the depressive symptoms decreased with SSRIs. CONCLUSION: Although cerebellar degeneration is irreversible in SCA patients, our cases suggest that MDD complicated with SCA may be reversible and treatable using antidepressants such as SSRIs with few adverse events. Therefore, it is important for neurologists to detect MDD complicated with SCA early and consult a psychiatrist in order to improve quality of life of SCA patients.