Purpose: Depression and anxiety are common among people with epilepsy (PWE), yet structured psychiatric screening remains infrequent in routine epilepsy care in Japan. Measurement-based care (MBC) using patient-reported outcome measures may enhance early detection and clinical decision-making. However, routine psychiatric screening remains limited in Japanese epilepsy care. Implementing MBC may help bridge this mental health service gap. This study evaluated the feasibility and clinical utility of integrating brief self-administered psychiatric screening tools into a tertiary epilepsy outpatient clinic. Methods: A prospective observational study was conducted from April 2023 to March 2024. Fifty-one adult PWE completed the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), Generalized Anxiety Disorder-7 (GAD-7), Epilepsy Self-Stigma Scale (ESSS), a subjective overall Quality of Life (QOL), and health degree, prior to routine consultations. Questionnaire completion rates, prevalence of depressive symptoms (NDDI-E > 16), and longitudinal changes at a nine-month follow-up were analyzed. Statistical analyses included t-tests, chi-square tests, correlation analyses, and repeated measures ANOVA. Results: Questionnaire completion was high across visits (baseline: 100%; nine months: 80%). Depressive symptoms were present in 49% of the participants. Those with depressive symptoms showed significantly lower QOL and health degree, with strong correlations between depression and anxiety (all p < 0.001). Repeated measures analyses revealed a significant improvement in subjective health over time (p = 0.031). Changes in depressive symptom trajectories did not differ clearly by antidepressant use, possibly reflecting limited statistical power. Conclusion: This study provides preliminary evidence supporting the feasibility and clinical utility of MBC focused on psychiatric symptoms in Japanese epilepsy outpatient care. Routine screening using brief patient-reported measures may enhance detection and monitoring of mental health concerns in PWE and contribute to more integrated and interdisciplinary epilepsy care.