Hello, In a person suffering from schizophrenia, some degree of cognitive impairments are the part of illness. However a memory impairment of one month duration in the later course of illness should raise a red flag. It seems to be less likely due to schizophrenic illness, and more likely to be independent. Possibility of dementia or Mild Cognitive Impairment (MCI) needs to be considered. Hence please discuss these issues with your psychiatrist, and if he finds something significant he may order some investigations and psychological tests. Hope this helps you. Best wishes for your health and future..