摘要:Purpose: This study was carried out to evaluate factors resulting in medication nonadherence within 6 months before admission to the psychiatric service of our hospital for bipolar disorder, schizophrenia/schizoaffective disorder, depression, and other psychiatric diseases. Patients and methods: Two hundred and three patients admitted to the Psychiatry Service of the Medical Faculty were included in this study. Sociodemographic parameters and clinical findings within 6 months before admission and patients’ views on reasons of medication nonadherence were examined. Results: Patients were classified into four groups according to their diagnosis: bipolar disorder (n=68, 33.5%), schizophrenia/schizoaffective disorder (n=59, 29.1%), depression (n=39, 19.2%), and others (n=37, 18.2%). The ratio of medication nonadherence was higher in the bipolar disorder group when compared to the groups with schizophrenia/schizoaffective disorder, depression, and other disorders (12.1%, 18.2%, and 24.2% vs 45.5%); however, the ratio of medication nonadherence was similar in schizophrenia/schizoaffective disorder, depression, and the others group. In logistic regression analysis, irregular follow-up (odds ratio [OR]: 5.7; 95% confidence interval [CI]: 2.92–11.31) and diagnosis (OR: 1.5; 95% CI: 1.07–1.95) were determined to be important risk factors for medication nonadherence. The leading factors for medication nonadherence were: “not willing to use medication”, “not accepting the disease”, and “being disturbed by side effects” in the bipolar disorder group, “not accepting the disease” in the schizophrenia/schizoaffective disorder group, “feeling well” in the depression group, and “being disturbed by side effects” in the other diseases group. Conclusion: Medication nonadherence is an important problem in psychiatric patients and should be dealt with by taking into account the diagnosis, attendance to follow-up appointments, and the patient’s attitude. Ensuring regular attendance to follow-up appointments, adjusting the management plan according to the diagnosis, and improving their thoughts about resistance to medication can be beneficial in terms of medication adherence.