Objective: Investigate the prevalence and the characteristics of mental illness in elderly outpatients at Songklanagarind Hospital, a university hospital in southern Thailand.

Material and Method: This was a cross-sectional study. We extracted the medical records of the outpatients aged over 65 years old diagnosed with a category (F) mental disorder in the International Statistical Classification of Diseases and Related Health Problems, tenth revision (ICD-10) over the periods between July 1 and December 31, 2014, from all outpatient medical records. We used R program for analyzing descriptive data.

Results: There were 31,329 patients, aged over 65 years, who visited the outpatient clinic. We found that 752 patients in this group had been diagnosed with mental disorders; the prevalence was 2.4%. The most common diagnoses were: mood disorders (0.89%), organic mental disorders (0.85%), and neurotic-somatoform disorders (0.51%). Most patients (85.5%) received some form of medication. For each visit, the average medical fee for these patients was 3,431.30 Baht (96.80 US dollar).

Conclusion: The prevalence of geriatric mental disorders, among the outpatients of Songklanagarind Hospital was much lower than the inpatient and community setting. This could be a reflection that some were under-diagnosed for these disorders in the outpatient clinics. One of these factors was the limited time available for each patient. We need some interventions and policies to detect these abnormalities early and thoroughly, so the patients would be receiving appropriate treatments, which in turn would provide them with a better quality of life.

Keywords: Mental disorder, Geriatric, Outpatient