A distinguishing feature of psychotic disorders is

psychosis is a type of illness where the patient does not have touch with reality and beleives in fantacy. it is charecterstically mentioned that these patients does not have insight. insight is defined has patient not having any understanding about their illness this lack of touch with reality and accepting the fantacy usually presents as delusions and hallucinations. suspisousness is considered to be at the idea level which even normal people can have and that cannot be considered as a distinguishing feuture for the diagnosis of psychosis Suspiciousness may be seen in delusional/paranoid psychotic disorders as well as a paranoid personality disorder, whereas impaired reality testing is the hallmark of psychotic experience. obsessions and compulsions are pa of neurotic illness and it is not a feuture of psychosis severe depression can present even without psychosis and hence it is not a distinguishing feuture for psychosis Reference: Oxford Textbook of Psychiatry; 3rd edition