The primary care physician’s most powerful screening tool for depression is patient observation and active listening skills.  Most depressed patients do not realize they are depressed – and this is especially true in elderly patients. A physician should consider that a patient may have depression in the setting of unexplained physical symptoms or complaints. The higher the number of somatic complaints that a patient has, the higher the risk that they may have a mood disorder. Other clues may be a patient with persistent worries or concerns about medical illness, complaints that do not respond to typical interventions, or complaints outright of anxiety or panic attacks.  Patients with substance abuse issues may also suffer from a mood disorder. A careful history of present illness, past medical history, social and family history, and review of systems may yield more important information for making the diagnosis.

The primary care physician should ask open-ended questions of the patient about normal patterns as well as variations to determine baseline function and mood.  Mood is a range of emotions that a person feels over a period of time, while affect is how a person displays his or her mood.  The presence of a mood disorder may affect a person’s concentration, attention, motivation, interest, and sleep, as well as energy level, hunger and satiety levels, sexual pleasure, and pain sensation. These patients also frequently lose interest and lose pleasure (anhedonia) in things, people, or activities that they used to enjoy. Interruption in personal relationships with others can be a side effect due to increasing anger and conflicts, lower frustration tolerance, or from apathy and lack of enthusiastic feelings towards other people. Patients with depression may become emotionally constricted and lose their emotional flexibility.

Depression can impair cognitive function.  Cognitive dysfunction is common and patients may state that when they watch television they lose the point of the story; they read the same page of a book over and over again without comprehension; or lose the point of conversations with other people. A depressed patient’s memories may amount to more of selective recall, and normal perceptions may become distorted. Severe cognitive impairment due to depression is known as pseudodementia, and may be seen in elder populations or patients with central nervous disorders.

Psychomotor activity is usually decreased in depressed patients. Psychomotor retardation is present when thoughts, motor movements, or speech are slowed down. Psychomotor agitation can also occur and is present when patients experience unintentional and purposeless movements – such as unstoppable crying, pacing around a room, or hand-wringing. Frequently patients may complain of insomnia. In addition to having difficulty falling asleep, depressed patients typically wake up in the middle of the night or early in the morning with feelings of sadness, anxiety, or thoughts of dread or doom. They may also sleep excessively or stay most of the day in bed.

Depressed patients may also have self-worth that goes through turbulent fluctuations. For depressed patients, past events may be viewed with extreme guilt and self criticism, and feelings of worthlessness. Patients may view themselves and their world as hopeless. Suicidal ideation or a history of suicidal attempts from the patient should be assessed. Asking depressed patients about recent bereavement is also important to note.

A past medical history of prior episodes of depression is a very important question because you may be observing a relapsing episode. In addition, the physician should inquire about a previous history of bipolar disorder because inappropriate treatment with an antidepressant-therapy alone in these patients may precipitate a manic episode.  It is also important to inquire about a family history of depression or bipolar disorder.

Adapted from Sharp, LK, Lipsky MS. “Screening for depression across the lifespan: a review of measures for use in primary care settings.” American Family Physician. 2002; 66: 1001-1008

All adult patients may benefit from being screened for depression. There are many formal screening tools available such as the Patient Health Questionnaire (PHQ) (see below), the Hospital Anxiety and Depression Scales in adults, the Geriatric Depression Scale in older adults, the Edinburgh Postnatal Depression Scale (EPDS) in postpartum and pregnant women, the Zung Self-Assessment Depression Scale, Beck Depression Inventory, General Health Questionnaire (GHQ), Center for Epidemiologic Study Depression Scale (CES-D). All positive screening results should lead to additional assessment that considers severity of depression and co-morbid psychological problems (e.g., anxiety, panic attacks, or substance abuse), alternate diagnoses, and medical conditions.The USPSTF does not recommend one screening test over another and the optimal interval for screening is unknown. Recurrent screening in patients with a history of depression, unexplained somatic symptoms, substance abuse, chronic pain, or co-morbid psychological conditions may be the most useful. Any screening test that is positive requires a full diagnostic interview using DSM-5 diagnostic criteria to determine the presence of major depressive disorder.

The Patient Health Questionnaire – 2 (PHQ-2) is a validated primary care tool for depression screening, and is favored because of the relative ease of using a two question tool and because the USPSTF believes that with current available evidence it is as effective as longer screening tools.

The Patient Health Questionnaire – 9 (PHQ-9) is a nine item questionnaire that can be completed by the patient before or during a primary care office visit. It is available in several languages. The PHQ-9 can reliably detect and quantify the severity of depression using the DSM-IV criteria for major depressive episode. The PHQ – 9 was created by Dr. Robert Spitzer, et al. at Columbia University and is copyright protected by Pfizer Inc. The PHQ – 9 is also useful for patient follow up visits to assess symptom management.