To estimate the prevalence of concomitant psychiatric disorders in neurological outpatients and to assess the value of simple screening questionnaires in the identification of psychiatric symptoms, we analyzed a total of 803 patients who visited neurology clinics with neurological symptoms over a six-month period. Using self-reported questionnaires, we assessed psychiatric symptoms, such as stress (Perceived Stress Scale, PSS), depression (Patient Health Question 9, PHQ9), and anxiety (Generalized Anxiety Disorder 7, GAD7). According to the disease subtypes, we analyzed the psychiatric scales based on gender and age group. The prevalence of psychiatric comorbidities was lowest in patients with cerebrovascular disease (CVD) and highest among patients with cognitive decline and epilepsy. The overall prevalence of psychiatric symptoms markedly decreased with age. This decline was statistically significant for all questionnaires (PSS ≥ 14, p for trend = 0.027; PQH9 ≥ 10, p for trend = 0.005; GAD7 ≥ 10, p for trend = 0.002) and was more pronounced in males. Considering the high incidence of undetected psychiatric comorbidities and their associated burden, proactive psychiatric management should be included in neurological care. Psychiatric questionnaires could also be an effective screening tool for identifying psychiatric symptoms accompanying neurological symptoms.