The human body is a miraculous thing. The mind-body connection is so endlessly complex that there are many things we still don’t understand, even with the use of technology. As psychologists, we probably appreciate this natural wonder more than other folks, especially since we are constantly trying to decode the mysterious ways the brain works.

Unfortunately, all of the things we have worked hard to understand about the brain can become muddled in the face of illness, when the symptoms we are so familiar with take on a different meaning…well, sort of.

Think about this: does depression feel the same whether it’s caused by a traumatic life event or a hormonal imbalance? Based on the common presentation of symptoms across patients and life circumstances, many would argue yes.

But while the in-vivo presentation of depression (or any other psychological disorder, for that matter) may look the same as the version caused by a medical condition, our understanding of the difference can mean all the difference for our patients.

More importantly though is how often we actually “catch” the associated medical diagnosis in the first place. Being a good clinician means being a good detective, especially if your patients report comorbid health disorders.

Many times, patients come into our office complaining of symptoms that we consider standard in therapy – things like depressed mood, nervousness, panic, or fatigue. It is easy to think we would make the extra effort to rule out medical problems as the cause. But let’s be honest – a lot of things can get in the way.

For starters, we are part of a profession that prides itself on empathy and service, and what that means is that we can easily become overworked and burned out. The truth is that sometimes we don’t get to all the things on our to-do list, like obtaining medical records or playing phone tag with physicians. After all, we’re human.

Actually, if we are even on this “team effort” track, we are on the right track. The most threatening error in ruling out medical diagnoses is not even considering them in the first place.

As clinicians, we tend to see and think in psychological terms and as such, we are more likely to practice confirmation bias regarding the causes of our patients’ symptoms. In other words, if depression walks into our office, we are probably more likely to think “trauma” than we are “hypothyroidism.”

But that doesn’t mean we shouldn’t always check for hypothyroidism (and a number of other medical conditions)! From a biopsychosocial approach, it is likely that both trauma and thyroid functioning are affecting this patient. But what if the depression only started after the patient stopped taking their thyroid medication?

It is our duty as clinicians to help figure out what is causing the patient’s psychological distress, even if nobody else has pinpointed it and even if it’s not caused by a psychosocial issue.

It’s easy to imagine why: if our example patient resumes their thyroid medication and the depression goes away, can we even make an ethical argument that this patient should continue to pay for our services?

Or let’s think about it in a different way. Suppose this patient comes in for services and we don’t check their medical history or make an attempt to investigate medical causes. Even if we provide the gold standard evidence-based treatment for this patient, will we be able to help them out of their depression? Likely not.

As their number one advocate, we owe it to them to investigate. Although it can be complex and difficult, there are a number of things you can do that will put you on the right path. To start, take a look at this basic table of some well-known offenders and how they present psychologically:

Diagnosis Estimated prevalence amongst US population [1] Symptoms [2]
AIDS 1.2 million dementia, depression, suicidal ideation, anxiety, delirium, apathy, psychosis
Brain Tumor 5,000 each year memory loss, cognitive decline, dementia, apathy, disinhibition, depression, dissociation, psychosis
Cancer 8.5% depression, anxiety, suicidal ideation, anorexia
Cardiac Arrhythmia or Congestive Heart Failure 5.3%; 5.8 million delirium, anxiety, panic, depression, insomnia
Cerebrovascular Accident (Stroke) 2.6% cognitive disorder and decline, personality change, depression, mania, psychosis
Diabetes Mellitus 12.6% panic attacks, depression, delirium
Epilepsy 1-2% depression, suicidal ideation, paranoid psychosis, cognitive impairment
Fibromyalgia 2% chronic fatigue, depression, anxiety
Hyperthyroidism 1.3% depression, anxiety, panic attacks, delirium, psychosis
Hypothyroidism 4.6% depression, suicidal ideation, cognitive slowing, apathetic personality, dementia
Kidney & Liver Failure 14%, depression, irritability
Menopause n/a irritability, depression, insomnia, anxiety, forgetfulness
Migraine 12% lethargy, irritability, anxiety, depression
Multiple Sclerosis 400,000 depression, mania, labile affect, cognitive impairment, dementia
Parkinson’s Disease 1 million depression, anxiety, dementia
Pernicious Anemia 0.1-2% personality change (irritability), forgetfulness, depression, psychosis
Protein Energy Malnutrition unknown apathy, cognitive changes, occasional psychosis
Rheumatoid Arthritis 0.6% depression, psychosis (rarely)

Taking even a brief look at this table demonstrates pretty clearly how even the “garden variety” diagnoses are often linked to common medical conditions. So, how can we improve our competence at screening and treating these comorbid mood symptoms caused by biological conditions?

1. Investigate

Take time to obtain a thorough medical history (or records, if your patient is comfortable signing a release). Until you have committed some of the shared symptoms to memory, make sure you look up your patient’s medical diagnoses and check out what types of psychological symptoms they are known to cause. Do the same thing with any medications your patient is taking.

Typically, you shouldn’t be spending precious time treating symptoms or side effects when that’s all they are, especially if medications can be added, changed, or adjusted first.

2. Research DSM Diagnoses

Take some time to familiarize yourself with the DSM diagnoses that end in “…due to another medical condition.” Our guidelines tell us that we shouldn’t be diagnosing symptoms as primary mental health disorders when a patient’s presentation is actually being caused by a medical disorder.

Know when to give this type of diagnosis versus when a standalone mental health diagnosis is warranted. Intervention for symptoms caused by a medical condition can have a different treatment focus than those caused by life circumstances. Goals of improving sleep, medication adherence, and coping skills may be more appropriate foci than those relating to underlying beliefs and life experiences.

3. Always Consider Prevalence

If a patient comes into your office complaining of headaches and changes in vision, are migraines or a brain tumor more likely to blame? Just as we are taught to consider prevalence of mental health diagnoses as we navigate the diagnosis process, the same is true for physical conditions.

It is good to know many different diagnoses that could cause the presenting symptoms, but keeping in mind how often you are likely to see those disorders can help keep you on the right track. For example, simply by understanding health trends, we are able to say that we are much more likely to encounter symptoms related to Type 2 Diabetes than we are Huntington’s Disease.

4. Consultation & Self-Education

Use these tools frequently! If you can consult with other clinicians, especially those that might have more experience in the health arena, it can help increase your competence and effectiveness as a health provider. As always, it helps to read, read, read. Seek out research, continuing education on health topics, or other opportunities that can make your detective work faster and easier.

5. Coordinate Care

Especially as integrated models become increasingly recognized as the gold standard of health service, coordinating care with other health professionals on the patient’s medical team is (theoretically) easier than ever before.

When working with a causal or comorbid health condition, physician consultation can help clarify what treatment approach will be most helpful for the patient. Knowing the medication regimen, patient’s level of adherence, and key lifestyle factors (think: stress, sleep, nutrition, and exercise) that most influence the course of the illness can provide direction and meaning for therapy for a disorder that would otherwise be treated differently.

6. Don’t Doubt Yourself!

This may be the most difficult one for some clinicians. It is easy to become self-conscious about medical knowledge when you are just starting out or consulting with medical personnel who sound like they are speaking a different language. But keep in mind that you have a unique perspective on how the patient’s symptoms – medical or psychological – are affecting their daily lives. In fact, you may be the only one who ends up putting together the puzzle pieces to find that their psychological symptoms are being caused by an undiagnosed medical disorder after all.



[2] Morrison, J., (1997). When psychological problems mask medical disorders: A guide for psychotherapists. The Guilford Press.

Katie Arfa, PsyD, NSCA-CPT