Loneliness or depression? How to know the difference
5/11/2026 by Zachary Scharf, M.D., M.B.A.
“Do you smoke 15 cigarettes daily?” Many people would answer “no” to that question. However, when asking about loneliness, the numbers are staggering. In 2023, Dr. Vivek Murthy, former surgeon general of the United States, declared that a loneliness epidemic was sweeping the nation. The statistics certainly make a strong case. According to a 2023 report released by the Department of Health and Human Services, about half of adults in the U.S. reported experiencing loneliness, and this was prior to the COVID-19 pandemic (view the entire report). Given that May is Mental Health Awareness Month, it is worth diving deeper into what exactly loneliness is and how it is related to and distinct from depression.
What is loneliness?
Loneliness is the perceived lack of emotional connection and the psychological discomfort that results. However, its effects go far beyond the psychological. Loneliness has been associated with a greater risk of cardiovascular disease, dementia, stroke and even premature death. To put it in simpler terms, the mortality impact is roughly equivalent to smoking up to 15 cigarettes per day. When such a feeling floods a society, devastating consequences in schools, workplaces and communities can result.
How does loneliness compare to depression?
While the two have significant overlap, loneliness is distinct from depression. Loneliness at its core is a frequently changing state. With loneliness, social interactions, re-connecting with family and friends and doing beloved activities can resolve this emotional state. In short, loneliness is addressed and helped by social connection and activity. Depression — often referred to as major depressive disorder in medical terms — is more persistent. Major depressive disorder is a longer term feeling of sadness, with loss of joy from normally pleasurable activities or interactions. Those with depression often do not find the same benefit from interacting with others and doing activities that they used to love.
If I am concerned, what are the next steps?
If you or a loved one is struggling with mental health concerns, including loneliness or depression, you should always feel empowered to talk with your clinician. When you discuss these concerns, your clinician will often start by asking you to complete a Patient Health Questionnaire-2 (PHQ-2). This questionnaire consists of two questions:
- Over the last two weeks, how often have you been bothered by any of the following problems?
- Little interest or pleasure in doing things.
- Feeling down, depressed or hopeless.
Depending on your responses, you may then be asked to complete a more in-depth questionnaire called the PHQ-9. Depending on these results, and your discussion with your clinician, treatment options, including therapy, medications and others, may be recommended.
Loneliness and depression are closely connected but distinct. Loneliness can lead to depression and depression can also lead to loneliness. Both can have significant negative consequences for one’s health, and patients should always feel empowered to discuss care options and resources with their medical team. Let’s all work together this May and beyond to destigmatize mental health and address this growing issue in our society.
Zachary Scharf, M.D., M.B.A., is an Internal Medicine resident for Mayo Clinic and serves as a primary care physician in the Baldwin Building in Rochester, Minnesota. He has particular interests in quality improvement, health policy and cancer screening.