Depression in adult patients with biotin responsive basal ganglia disease.

Biotin responsive basal ganglia disease (BBGD), is a potentially treatable inherited metabolic disorder which clinically presents as sub-acute encephalopathy in children. Early diagnosis and treatment of this disorder results in good clinical recovery in childhood. However, there is no report in the literature on the long term outcome of these treated patients in adult life. We report two patients with BBGD who were metabolically stable on treatment and developed depression later in life. These cases highlight the association of depression with basal ganglia disorders and demonstrate that depression is the potential long term complication of BBGD.