This paper describes the use of Tepribaskog model to assess the violations of maxim of quality in Bahasa Indonesia and the psycho-cognitive disorder among schizophrenia in Medan. Maxim in general has a sense of conversation, and the participants are expected to work together with friends to produce effective and efficient communication. According to Grice, in order to communicate, among participants can run smoothly, then in the utterance the participants must meet the rules that Grice calls the principle of cooperation. Grice states "is your utterance desired at the time of speech, on the basis of the objective of the agreed speech, according to the facts that occur in society and in accordance with the rules that apply in linguistics correctly". If the speech is not in accordance with the rules of language, not in accordance with the facts of linguistic truth, then the person has committed violation of the principle of cooperation. According to Videback, Shadoch and Shadoch [1] and Cummings, the tendency of maximal offenses is caused by the impaired thinking, hallucinations, showing the withdrawal of society, the face without expression and loose association. It affects health, social life, language behavior and other negative effects. Thoughts or ideas are split and very disturbing in communicating, so the patient's speech becomes very bad. The Tepribaskog model is expected to provide a solution to reduce the negative effects of schizophrenics, which in fact can also affect all aspects of the patient's life: social interaction, emotional health, and work ability. With Tepribaskog, a long-term management strategy can be done as short as possible by nurses in hospitals, by families at home without spending money and is very efficient and done with great patience and affection.