The Importance of Differential Diagnosis

Plus Earn 1 Free CE Hour on DSM-5® Differential Diagnosis for Clients with a History of Trauma

PESI Team, Margaret L. Bloom, Ph.D.

When clients have a history of trauma, it can be difficult to determine whether the anxiety, isolation, and mood changes are due to trauma, other related diagnoses, or something completely different.

In fact, according to the National Academics of Science, Engineering and Medicine, “it is estimated that 5 percent of U.S. adults who seek outpatient care each year experience a diagnostic error.”

This error rate is speculated to jump up to at least 10 percent when diagnosing mental disorders—due to the multiplicity of signs and symptoms—although this rate is not well documented.

Making differential diagnosis a part of your process


One of the key ways mental health professionals can reduce errors in mental health diagnosis is by always including a differential diagnosis as part of the diagnosis process.

Differential diagnosis is an important step in any diagnosis, but can be even more critical when a client has a history of trauma. This is because the symptoms of trauma regularly overlap with other diagnoses.

For example, when clients don’t reveal their history with trauma, their symptoms of mood swings and sleep problems could be misdiagnosed as depression or anxiety. On the other hand, if clinicians are aware of a client’s traumatic history, it can be easy to default to a diagnosis of PTSD and miss other possible disorders.

How to start differential diagnosis


Once you have conducted the initial interview and identified the client's key symptom patterns, the next step in accurate diagnosis is generating a differential diagnosis. To correctly execute differential diagnosis, you must complete two phases:

Phase One: Generate a list of all POSSIBLE diagnoses
Phase Two: Narrow the list to most PROBABLE diagnoses

Phase one requires practitioners to go broad and think of anything that could be possible given the syndromes a client has. That list is then narrowed in Phase Two, detailing the more probable diagnoses.

Learn some helpful tips on how to generate you first, broad list of all possible diagnoses in this short video clip:


Note: This clip is taken from a FREE, one-hour CE video on DSM-5® Differential Diagnosis for Clients with a History of Trauma, which discusses a case study about a man named Roger. Roger was diagnosed with Post Traumatic Stress Disorder four years ago, but is now exhibiting new changes in behavior.

Learn more about Roger, how to narrow your differential diagnosis list, and how to make the most accurate diagnosis possible in the full, FREE one-hour CE video.

If you’re interested to learn proven, step-by-step formulas that will streamline your paperwork processes, help you avoid common diagnostic errors, and improve your client outcomes… then check out our bestselling online course, Mastering DSM-5® Differential Diagnosis, Mental Health Documentation & Medical Necessity.

Improve your clinical outcomes and streamline your processes… even with the most challenging cases.

Meet the Course Expert:
Margaret (Peggy) L. Bloom, PhD, a licensed psychologist and NCC, is a Professor Emerita of Counselor Education and Counseling Psychology at Marquette University in Milwaukee, Wisconsin. Beginning with the introduction of the DSM-III-R, then the DSM-IV, and now the DSM-5®, Dr. Bloom has conducted DSM seminars across the United States for hundreds of psychologists, professional counselors, social workers and other mental health professionals. For more information on Dr. Bloom, go to:

Learn more about her educational products, including upcoming live seminars, by clicking here.

Topic: DSM | Trauma

Tags: Challenging Clients | Therapy Tools | Tools | Trauma | Trauma Treatment

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