The results of the 24 datasets, only the datasets with the consequence of “schizophrenia” in the association rule were selected to represent the results of the study (Table 4.2). From the dataset No.11, 94% of the patients diagnosed with amphetamine use in the duration of 7 to 12 months were likely to have schizophrenia with the measure of rule 1.39, and with the strong belief of rule 5.21. From the dataset No.12, 96% of the single male patients in Bangkok diagnosed with nicotine use in diagnosis at the age of 35 to 44 years old were likely to have schizophrenia with the measure of rule 1.42, and with the strong belief of rule 7.82. From the dataset No.22, 95% of the patients diagnosed with nicotine dependence, and amphetamine dependence were likely to have schizophrenia with the measure of rule 1.41, and with the strong belief of rule 6.84. From the dataset No.24, 96% of the single male patients in Bangkok diagnosed with nicotine dependence in the age of 35 to 44 years old were likely to have schizophrenia with the measure of rule 1.42, and with the strong belief of rule 7.82. To put the results together, the single male in Bangkok diagnosed with nicotine and/or amphetamine use and/or dependence at the age of 35 to 44 years old with the use of a period of 7 to 12 months was at associated with having schizophrenia.