A blinded evaluation of 123I-ioflupane SPECT demonstrated an underlying nigrostriatal deficit in 7 out of 29 patients with LOD with patterns usually associated with PD9 and DLB.10 Previous investigations of striatal dopamine transporter in those with major depression (with no studies specific to LOD) have reported mixed results, possibly due to inclusion of different populations of patients, types of depressive disorder and the use of different imaging tracers. This evidence concerns the gene SLC6A3 and major depressive disorder.