GAD2 and neoplasm: However, there has been no evidence that glutamic acid decarboxylase 65 (GAD65) autoantibodies in cerebrospinal fluid (CSF) are associated with akinetic catatonia in schizophrenia patients.<h4>Methods</h4>We report the case of a 28-year-old man who underwent diagnostics including brain MRI, neuropsychological testing, and electroencephalography (EEG) as well as a tumor search <i>via</i> CT of the abdomen and thorax, as well as colonoscopy and gastroscopy.