Prevalence and Impact of Diagnosed and Undiagnosed Depression in the United States.

ABSTRACT

BACKGROUND: The objectives of this study were 1) estimate the impact and severity of both diagnosed and undiagnosed depression in the general US population 2) explore the demographics of depression based on its common symptoms 3) interpret Patient Health Questionnaire-9 (PHQ-9) scores to improve accuracy in identifying individuals with depression. METHODS:  A random sample of 200 individuals was selected from a general US adult population to complete the Patient Health Questionnaire-9 (PHQ-9). RESULTS: Only 39.4% of respondents indicated that they had a formal diagnosis of depression. In contrast, 53% of participants have considered seeking help from a mental health professional. More importantly, 31.45% of respondents without a formal diagnosis had a PHQ-9 score of over 10 (moderate to severe depression). CONCLUSIONS: The results indicate that undiagnosed depression exists in the US population and suggest that access to mental health services needs to expand across the nation.