According to the Mayo Clinic, depression (also known as major depressive disorder) is one of the most common diseases in the world. Most physicians view it as a chronic illness (similar to high blood pressure or diabetes), and it can be effectively treated using a variety of approaches. For depression to be accurately diagnosed, the patient's emotional and mental state must be examined and other potential causes of the symptoms must be ruled out via a physical exam and blood tests.
Step 1
Perform a thorough mental health interview as well as a mental status evaluation. According to Intellihealth (which is reviewed by faculty from Harvard Medical School), the mental health interview is critical for the diagnosis of depression. It begins with asking the patient about what kinds of symptoms he has been experiencing (such as abnormally low mood, feelings of worthlessness, changes in sleeping or eating behavior, as well as loss of interest in activities). It is also important to ask about when these symptoms first appeared, how does the patient experience them, and about what other events are going on in the patient's life. With the mental status evaluation, you should check the patient's attentiveness and speech, as well as her expressions and appearance. Depressed people often have trouble paying attention, speak more slowly or haltingly, and appear withdrawn and have little interest in grooming.
Step 2
Perform a complete, thorough physical exam. According to the Mayo Clinic, sometimes the symptoms of depression can be caused by other physical problems. The physical exam can help alert you to other conditions that could be related. The exam should include height, weight and blood pressure measurements, as well as taking the patient's pulse, listening to his heart and lungs and examining the abdomen.
Step 3
Have blood tests done. Important blood tests include a complete blood count (some disorders that cause symptoms of depression also lead to alterations in the patient's blood cells) as well as a drug and alcohol screen (alcohol and drug abuse as well as certain medications can cause depression). Finally, you should check the patient's thyroid function via tests done on her blood, because poor thyroid function can lead to poor mood and lethargy.
