Dementia with Lewy bodies（DLB）has recently often been reported to exhibit various psychiatric symptoms. However, some DLB patients do not present typical clinical courses or psychiatric symptoms. We report two DLB patients with characteristic psychiatric symptoms : a depressive state and anxiety in the early stage, and auditory hallucination, delusion of guilt, and catatonia in the later stage. Pharmacotherapy was ineffective, but electroconvulsive therapy proved to have a marked effect. The clinical course represents the symptomatic concept of “late catatonia,”which Sommer first reported in 1910 and Kocha later reappraised. In Japan,this has been prevailing as a useful concept in the field of clinical geriatric psychiatry. We discuss what to consider and how to treat DLB patients including those with atypical courses and psychiatric symptoms. We consider and treated them as“late catatonia”,with a favorable response to treatment. There is an important viewpoint which helps us understand the process. The viewpoint is to distinguish between “genera”and “types”of mental illnesses as inherited from classical psychopathology to modern psychiatry. DLB corresponds to “genera”and late catatonia to “types.” In treating DLB patients with atypical symptoms and courses,it appears clinically very important to think more about late catatonia, exhibiting characteristic symptoms. This also reveals the usefulness of understanding and treating such cases based on the concept of “genera”and “types.”