<prompt> A patient of Schizophrenia on neuroleptics, his psychotic symptoms gets relieved but developed sadness, talks less to others, remain on bed, all of following are likely causes except:ParkinsonismMajor depressionNegative symptoms are still persistingHe is reacting to external stimuli  <response>: D i.e. He is reacting to external stimuliPost psychotic depressive disorder of schizophrenia occurs only during the residual phase of schizophrenia in 25Differential diagnosis of post psychotic depressive disorder of schizophrenia are - Residual phase negative symptoms of schizophrenia- Adverse effects eg. parkinsonism, akinesia, akathisia of antipsychotic drugs - Schizoaffective disorder - depressive type 