One small study of five patients suggested that dopaminergic abnormalities—at least presynaptically—are transient: five older women with catatonia and depression underwent a DAT-SPECT, which uses 123I-FP-CIT-SPECT to ascertain the density of DAT in the presynaptic terminal, finding reduced binding in the striatum, which improved after treatment with benzodiazepines or electroconvulsive therapy (ECT).138 One possible interpretation is that the reduction in DAT might be a compensatory response to reduced synaptic dopamine levels. Here, SLC6A3 is linked to major depressive disorder.