Finding the right diagnosis for any disorder requires a comprehensive evaluation. Indeed, many illnesses share many of the same symptoms.
Take symptoms such as headache, stomachache, dizziness, fatigue, lethargy, insomnia and appetite loss. There are countless conditions with these exact indications.
Similarly, many mental illnesses share the same symptoms, said Stephanie Smith, PsyD, a psychologist in practice in Erie, Colo., who specializes in working with individuals with depression. Which makes “the process of diagnosing mental illness tricky, to say the least.”
For instance, attention deficit hyperactivity disorder (ADHD) and bipolar disorder can look like depression. All three cause difficulty concentrating, trouble sleeping, and increased worry, Smith said.
Anxiety also mimics depression. According to psychotherapist Colleen Mullen, PsyD, LMFT, like individuals with depression, people who struggle with anxiety might not want to get out of bed. They might stop going to work. They might withdraw socially. However, depression isn’t driving the person’s behavior. Anxiety is.
“An anxious person may stop engaging in their outside world because of the level of anxiety they experience when they try to leave their home.” Because of this, they might, understandably, become depressed, as well. Still, it’s important to treat the anxiety symptoms first (which, in turn, will help to diminish the depression), said Mullen, founder of the Coaching Through Chaos private practice and podcast in San Diego.
Post-traumatic stress disorder (PTSD) is another condition that’s hard to distinguish from major depression. According to Mullen, “PTSD and depression share the following symptoms: memory problems, avoidant behaviors, reduced interest in activities, negative thoughts or beliefs about self or others, inability to concentrate, feeling disconnected from others, irritability and sleep disruptions, and of course, mood changes towards negative emotions.” The biggest tell-tale sign of PTSD is that a person experiences or is exposed to a traumatic or tremendously emotionally straining situation, she said.
Medical conditions mimic depression, too. Two examples are chronic fatigue syndrome and low blood pressure, Mullen said. In this piece Psych Central blogger and author Therese Borchard discusses six conditions that feel like clinical depression but aren’t: vitamin D deficiency; hypothyroidism; low blood sugar; dehydration; food intolerance; and even caffeine withdrawal.
Gary S. Ross, M.D., believes all patients diagnosed with depression should be screened for thyroid dysfunction. As he writes in his 2006 book, Depression & Your Thyroid: What You Need to Know:
There may be rare cases of depression that cannot benefit from thyroid treatment. Nevertheless, in every case of depression, it is optimal practice to test very thoroughly for thyroid dysfunction, much more thoroughly than is usually done in initial screening examinations. When the testing is thorough, then if anything is found in keeping with a low thyroid function, it is crucial to include some kind of thyroid treatment protocol in the overall treatment plan for maximum benefit to the patient.
(Learn more about testing and diagnosis in this piece.)
Having the correct diagnosis is vital. “[I]t leads to a more precise, effective treatment plan,” Smith said. “If we don’t know what we’re dealing with at the beginning of treatment, our interventions can be like shooting arrows in the dark: not very accurate and possibly dangerous.”
Indeed, an accurate diagnosis is life-saving. Literally. Mullen has heard horror stories of primary care physicians diagnosing women with depression when their sluggishness, depressed mood, and weight gain were actually symptoms of cancer. Similar symptoms also may be due to a heart condition, which if undiagnosed, puts a person at risk for severe medical consequences, she said.
This is why it’s so important to have a comprehensive evaluation. See your primary care physician for a series of tests to rule out medical conditions. Ask for a referral to a therapist who specializes in mood disorders, so you can receive a psychological evaluation.
What does a thorough psychological assessment look like?
“[A] good clinical interview includes lots and lots of questions,” Smith said. She asks everything from how long clients have been experiencing their low mood to whether they’ve recently had any changes in their life. Mullen takes into account the person’s current stressors and psychosocial history. The latter involves assessing social support—or lack thereof—and work, education, legal, medical and family history. “It helps us understand the person in the full context of their life thus far.”
Smith also might give objective screening measures such as the Beck Depression Inventory. “It can take one to four sessions to get all the information I need to make a fully informed diagnosis.”
You may or may not be struggling with depression. As Smith said, “depression is a condition almost everyone is familiar with, so it can easily become a catch-all phrase or diagnosis. But there are literally hundreds of other mental health disorders, one of which may better capture the symptoms you are experiencing.”
Either way, take your symptoms seriously and seek second opinions, Mullen said. Because you know yourself better than any professional who spends several hours assessing your symptoms. “Advocate for yourself and ask questions so that you understand what [the professional] recommends for a treatment plan and why.” This is your body. Your mind. Your health and well-being. Advocating for yourself in all areas of your life is one of the best things you can do.