The association between neuroleptic treatment and the negative symptom dimension (ND) was evaluated in 1528 schizophrenia patients. In patients receiving more than 820 mg chlorpromazine (CPZ), those with catatonic-type disorder had significantly (p<0.05) higher ND scores than those in any of the other diagnostic subtypes. Even in patients receiving 450 mg CPZ or more, catatonic patients had significantly (p=0.046) higher ND scores than other patients. Patients with catatonic schizophrenia are highly vulnerable to negative symptoms related to neuroleptic drugs, probably because of a defect in their dopaminergic neuronal pathways.