Using the PHQ-9 Scale to assess depressive symptoms in patients with schizophrenia: a clinical perspective

Background and objectives. Schizophrenia is a chronic psychiatric disorder characterized by complex symptomatology, including both positive and negative manifestations. Depressive symptoms are frequently overlooked in these patients, despite their impact on quality of life and their known association with increased suicide risk. The aim of this study was to assess whether the Patient Health Questionnaire-9 (PHQ-9) is effective as a screening tool to identify depressive symptoms and suicidal ideation among patients with schizophrenia. Materials and methods. We conducted a cross-sectional observational study involving 30 patients diagnosed with schizophrenia, hospitalized in Psychiatric Clinic I, Targu Mures, Romania, between March and May 2025. Each participant completed the PHQ-9, a validated tool assessing the frequency and severity of depressive symptoms over the past two weeks, including a specific item addressing suicidal ideation. Results. Among the 30 patients, the most commonly reported symptoms were: feeling down, depressed or hopeless – 18 patients (60%) nearly every day; feeling bad about themselves – 17 (57%) more than half the time; little interest or pleasure in doing things – 10 (34%) more than half the time; trouble falling asleep – 24 (83%) on several days. Suicidal ideation was reported by 13 patients (43%): 7 (23%) on several days, 4 (13%) more than half the days, and 2 (7%) nearly every day. Conclusions. The PHQ-9 proved to be a practical and efficient tool for screening depressive symptoms in patients with schizophrenia, even in a limited-resource setting. Further research on larger and more diverse populations is needed.