GSTM2 and schizophrenia: As enzymes of the GSTM class are involved in the detoxification of oxidized metabolites (o-quinones) of catecholamines [26,28], unlike the enzyme encoded by GSTT1, which is involved in the metabolism of a wide range of compounds [15], we can hypothesis that a summation of deficiencies in the capacity to eliminate oxidized metabolites can lead to the damage of dopaminergic pathways reported to occur in schizophrenia and its refractory manifestation.