Depression is a leading cause of disability and death in the United States, especially in younger population demographics. It results in millions of hours of missed work per years, many broken relationships and ultimately thousands of lost lives. Suicide is currently the 10th leading cause of death amongst all age groups in the U.S [1]. 
The majority of cases of depression are treated in the primary care clinic, not by psychiatry or other medical specialties. Primary care providers are in a unique position to screen for depression and suicidal ideation, partially because patients are seen more frequently than in other areas of medicine, but also because of the established relationship between the patient and the provider. A patient may feel more comfortable to divulge issues they are having with their mental health to a trusted primary care clinician than they would be to another member of their care team. However, studies have shown that  as many as 50% of cases of depression (including major depressive disorder) will go undiagnosed without proper screening [1]. 
There are several different screening tools that can be utilized while the patient is being checked-in by their nurse/ medical assistant, most common of which is the PHQ-9. This is a questionnaire consisting of nine questions, which mirror the DSM-5 criteria for major depressive disorder. Another option is the PHQ-2, which focuses on the two core symptoms of anhedonia and feeling down, depressed, or hopeless. While there are no guidelines on exactly how often to screen (this is up to the clinician’s judgement), it is recommended to screen regularly and specifically during pregnancy and the post-partum period. 
The screening can either be done by the patient, or can be used as a guideline for the clinician to discuss with the patient. If time permits, it may be advisable to ask the questions directly to the patient, as tone and inflection in answering questions may prompt further conversation. For example, if a patient is asked whether they are having thoughts of suicide, and looks down for several seconds before stating “I guess not” while avoiding eye contact, this would be concerning and a point which most clinicians would press. However, if the patient simply circled “no” on the questions asking about suicide, this point of intervention may be lost. 
It is important for clinicians to help reduce the stigma around mental health, and primary care is an excellent place to start. As the predominant location that patients receive care, it is helpful in setting the tone of that patient’s interaction with the greater health care system. If the clinician feels that the patient does have MDD or significant depressive symptoms, they will have the opportunity to either start medications, refer to psychiatry or counseling, or a combination therein. Mental health is a major component of physical well-being, and screenings for depression and suicidal ideation should be included as a routine component of holistic patient centered care.