Many medical conditions cause or worsen psychiatric symptoms — and many psychiatric conditions show up as physical ones. Getting the diagnosis right, and treating both sides of the equation, requires a clinician trained in both medicine and psychiatry.
How Medical Conditions Can Cause Psychiatric Symptoms
Many medical and neurological conditions can directly cause or worsen psychiatric symptoms including depression, anxiety, cognitive impairment, and mood instability. When this occurs, standard psychiatric treatments may be ineffective unless the underlying medical problem is also identified and managed. This is where Dr. Brendel’s training in both medicine and psychiatry becomes particularly relevant — he’s trained to look for medical contributors that a standard psychiatric evaluation might miss.
Endocrine Disorders
Hypothyroidism, hyperthyroidism, Cushing’s syndrome, Addison’s disease, and diabetes can cause depression, anxiety, fatigue, and significant cognitive changes.
Neurological Conditions
Brain tumors, seizure disorders, multiple sclerosis, traumatic brain injury, and Parkinson’s disease frequently manifest with prominent psychiatric symptoms.
Anemia & Blood Disorders
Chronic anemia reduces oxygen delivery to the brain, causing fatigue, cognitive fog, irritability, and symptoms that closely mimic major depression.
Kidney & Liver Disease
Kidney failure and liver disease (including cirrhosis) can cause metabolic encephalopathy, presenting as personality changes, confusion, depression, and emotional dysregulation.
Autoimmune & Rheumatological Disorders
Lupus, Sjögren’s syndrome, rheumatoid arthritis, and similar conditions frequently involve neuropsychiatric manifestations — sometimes as their very first presentation.
Gastrointestinal Disorders
Inflammatory bowel disease, celiac disease, and gut-brain axis disruptions are increasingly linked to depression, anxiety, and cognitive symptoms through complex neuroimmune pathways.
Sleep Disorders
Untreated sleep apnea, circadian rhythm disorders, and chronic insomnia profoundly affect mood, cognition, and emotional regulation — and are frequently overlooked as contributors to psychiatric symptoms.
Nutritional Deficiencies
Deficiencies in vitamin B12, folate, vitamin D, and iron can produce or significantly worsen depression, anxiety, fatigue, and cognitive decline.
When Psychiatric Disorders Present with Physical Symptoms
But the connection runs both ways. Several psychiatric conditions present primarily with physical symptoms, leading patients through extensive medical workups before a psychiatric diagnosis is considered — and making accurate assessment by an experienced psychiatrist especially important.
Somatic Symptom Disorder
Persistent physical symptoms — pain, fatigue, gastrointestinal distress — driven primarily by psychological factors, causing significant distress and functional impairment despite negative medical workups.
Conversion Disorder
Neurological symptoms including weakness, tremor, paralysis, or sensory changes that arise from psychological distress rather than neurological disease — requiring careful evaluation to distinguish from true neurological illness.
Depression with Physical Symptoms
Major depression frequently presents with fatigue, pain syndromes, appetite and weight changes, and GI symptoms that can closely mimic medical illness — especially in patients who are reluctant to attribute symptoms to a psychiatric cause.
Anxiety with Physical Manifestations
Panic disorder can mimic cardiac and respiratory conditions. Health anxiety (illness anxiety disorder) can drive extensive — and ultimately unrevealing — medical investigation without an underlying physical diagnosis.
Integrated Medical-Psychiatric Care
My training spans both medicine and psychiatry, which means I rarely lose sight of how deeply physical and mental health affect each other. In every evaluation, I’m thinking about whether there’s a medical factor that needs attention — and I work directly with neurologists, internists, endocrinologists, and other specialists to make sure patients get coordinated care.
Dr. Brendel maintains active working relationships with neurologists, endocrinologists, rheumatologists, internists, and other subspecialty physicians throughout the Boston area and beyond. When a patient’s psychiatric symptoms may be influenced by an underlying medical condition, he coordinates directly with the appropriate specialists to ensure thorough evaluation and integrated co-management of care.
If you or a loved one may be experiencing symptoms at the intersection of medical and psychiatric illness, Dr. Brendel — a Harvard-trained, board-certified private psychiatrist in Belmont, MA with over 25 years in practice — would be glad to meet with you. You can book online via ZocDoc, call (617) 932-1548, or email David@DrDavidBrendel.com.
Frequently Asked Questions
How do I know if my psychiatric symptoms have a medical cause?
Clues include: psychiatric symptoms that began alongside a new medical diagnosis, unusual symptom patterns that don’t fit classic psychiatric presentations, a family history of medical conditions, or symptoms that haven’t responded to standard psychiatric treatment. A thorough evaluation by an experienced psychiatrist is the best way to clarify the picture.
Will Dr. Brendel coordinate with my primary care doctor or other specialists?
Yes. Coordinating care with primary care physicians, neurologists, endocrinologists, and other relevant specialists is a core part of Dr. Brendel’s approach for patients with medical-psychiatric comorbidities. He communicates directly with your medical team as needed.
Can treating a medical condition resolve psychiatric symptoms?
In many cases, yes. Treating an underlying thyroid disorder, correcting a nutritional deficiency, or managing sleep apnea can produce dramatic improvements in mood, cognition, and anxiety — sometimes without any psychiatric medication. This is why identifying medical contributors is so important early in the treatment process.
What specialists does Dr. Brendel work with?
Dr. Brendel maintains active referral relationships with neurologists, endocrinologists, rheumatologists, internists, and other subspecialty physicians in the Boston area. When a patient’s symptoms suggest a medical contributor, he coordinates directly with the appropriate specialist to ensure thorough evaluation and integrated care.
What should I bring to my first appointment?
Bring a list of all current medications, any recent lab results or imaging reports, a summary of relevant medical history, and notes on when your psychiatric symptoms began and how they have evolved. The more context Dr. Brendel has from the start, the more focused and useful the evaluation will be.
Does Dr. Brendel accept patients who have already seen other psychiatrists?
Yes. Many patients seeking care for medical-psychiatric comorbidities are looking for a second opinion or a more thorough evaluation after previous treatment has not produced the expected results. Dr. Brendel welcomes these cases and brings a careful, fresh perspective to complex diagnostic challenges.
Concerned About Medical & Psychiatric Comorbidities?
Dr. Brendel specializes in the complex intersection of medical and psychiatric illness. Accepting new patients for comprehensive evaluation in Belmont, MA.