Medical Disorders and Their Psychiatric Manifestations: A Clinical Reference
This is Part 5 in our series on the Medical History
Read Part 4 – Seizure Disorders in Psychiatric Patients: Mimics, Comorbidity, and Medication Risks
In Part 1 we established a framework for recognizing when psychiatric symptoms may have medical or neurological etiologies. We reviewed the key red flags: abrupt onset after age 40, atypical clinical features, physical and neurological signs, temporal associations with medical events or medications, and prodromal presentations. This part provides a comprehensive reference table documenting specific medical conditions and the psychiatric symptoms with which they are associated.
The table that follows is organized by organ system and disease category, systematically cataloging which psychiatric symptoms, neurological signs, and sleep disturbances have been documented in association with each medical disorder. For each condition, we also provide the recommended diagnostic workup to identify or rule out that disorder as a contributor to psychiatric symptoms. This reference serves multiple clinical purposes: guiding your differential diagnosis when evaluating new psychiatric symptoms, informing your workup strategy when medical etiologies are suspected, and facilitating communication with medical and surgical colleagues about psychiatric manifestations of their patients’ conditions.
Learning Objectives
After reviewing this reference, you should be able to:
- Identify which psychiatric symptoms are associated with specific medical disorders across neurological, infectious, endocrine, metabolic, and systemic disease categories
- Generate an appropriate differential diagnosis when a patient presents with psychiatric symptoms and known medical comorbidities
- Formulate an initial diagnostic workup plan based on the pattern of psychiatric symptoms and suspected medical contributors
- Recognize that many medical conditions produce multiple psychiatric manifestations, not just a single symptom presentation
- Communicate effectively with medical specialists about psychiatric symptoms their patients may experience as manifestations of underlying medical illness
Psychiatric Symptoms in Medical Disorders: Clinical Reference
A comprehensive quick-reference guide for identifying medical conditions associated with psychiatric presentations.
How to Use This Reference Clinically
Scenario 1: Patient with Known Medical Condition Develops Psychiatric Symptoms
When a patient with an established medical diagnosis develops new or worsening psychiatric symptoms, consult the table to determine if their medical condition is known to produce those specific psychiatric manifestations.
Example: A 52-year-old woman with systemic lupus erythematosus presents with new-onset depression and cognitive complaints. Consulting the table reveals that SLE is associated with depression (up to 40% prevalence), cognitive impairment (up to 80%), anxiety, psychosis, and acute confusional states. This finding:
- Increases suspicion that her symptoms may be neuropsychiatric SLE rather than primary psychiatric illness
- Guides workup (ANA, complement levels, anti-dsDNA, neuroimaging if indicated)
- Prompts coordination with rheumatology regarding SLE disease activity and treatment
- Informs prognosis (neuropsychiatric SLE symptoms may improve with immunosuppressive treatment)
Scenario 2: Psychiatric Symptoms with Atypical Features
When psychiatric symptoms have atypical features suggesting possible medical etiology, use the table to generate a differential diagnosis and workup strategy.
Example: A 45-year-old man presents with first-episode mania, no prior psychiatric history, no family history of bipolar disorder. He also reports hand tremor and heat intolerance. The table shows that hyperthyroidism is associated with mania, anxiety, depression, psychosis, mood lability, and sleep disorders. Recommended workup: TSH and free T4. This clinical reasoning:
- Prevents premature diagnosis of primary bipolar disorder
- Identifies a treatable cause (thyroid storm can be life-threatening)
- Guides treatment (addressing hyperthyroidism rather than starting mood stabilizers)
- Clarifies prognosis (psychiatric symptoms may resolve with thyroid treatment)
Scenario 3: Multiple Psychiatric Symptoms Suggesting Organic Etiology
When a patient presents with an unusual constellation of psychiatric symptoms, the table helps identify medical conditions that produce similar symptom patterns.
Example: A 35-year-old woman presents with episodic panic-like symptoms lasting 1-2 minutes, accompanied by epigastric rising sensation, déjà vu, and automatisms (lip smacking). After episodes, she is confused for several minutes. The table shows that temporal lobe epilepsy/partial complex seizures are associated with panic symptoms, anxiety, depression, mania, psychosis, delusions, episodic features, and OCD. Recommended workup: EEG, MRI brain, video EEG monitoring. This pattern recognition:
- Prevents misdiagnosis as panic disorder or dissociative disorder
- Prompts appropriate neurological evaluation
- Avoids ineffective psychiatric treatment and delays in seizure management
- Identifies a condition requiring antiseizure medication, not anxiolytics
Scenario 4: Treatment-Resistant Psychiatric Symptoms
When psychiatric symptoms do not respond to standard treatment, review the table for medical conditions that may be missed contributors.
Example: A 60-year-old man with “treatment-resistant depression” has tried multiple antidepressants without response. He also reports fatigue, cold intolerance, weight gain, and constipation. The table shows hypothyroidism is associated with panic, anxiety, depression, and psychosis. Recommended workup: TSH. Finding TSH of 12.5 explains treatment resistance and guides appropriate intervention (thyroid replacement, with psychiatric symptom reassessment after euthyroid state achieved).
Important Caveats and Limitations
The table documents associations, not causation: A “+” marker indicates that psychiatric symptom has been reported in association with that medical condition in published literature. This does not mean every patient with that condition will experience those symptoms, nor does it prove the medical condition caused the psychiatric symptoms in any individual case. Clinical judgment, temporal relationships, and comprehensive evaluation remain essential.
Absence of a “+” does not rule out the association: Blank cells indicate the symptom is not commonly or consistently reported with that condition. However, individual patients may present atypically, and emerging literature may document associations not yet widely recognized. Absence of a marker should not prevent clinical consideration when the presentation suggests a connection.
Prevalence and severity vary widely: A “+” marker does not convey how common or severe the psychiatric symptom is in that condition. Some associations are nearly universal (e.g., cognitive impairment in Alzheimer’s disease), while others occur in a minority of patients (e.g., psychosis in hyperthyroidism). The “Additional Information” sections provide prevalence data where available.
Multiple mechanisms may be operative: Medical conditions can produce psychiatric symptoms through direct effects on brain function (structural damage, neurotransmitter disruption, inflammation), indirect effects (metabolic derangements, hypoxia, medication side effects), or psychosocial impact (chronic pain, disability, fear of disease progression). The table does not distinguish mechanism, and clinical evaluation should consider all pathways.
Temporal relationships matter: A patient may have both a medical condition and an independent primary psychiatric disorder. The presence of a medical condition on this table does not automatically mean it is causing current psychiatric symptoms. Careful history regarding temporal relationships (did symptoms predate the medical diagnosis? did symptoms emerge or worsen with disease activity?) is essential for attribution.
Workup recommendations are starting points: The “Associated Work-Up” column provides initial diagnostic studies appropriate for most patients. Individual clinical scenarios may require more extensive evaluation, specialist consultation, or serial monitoring. These are guidelines, not rigid protocols.
Clinical Integration: Connecting the Table to Your Assessment
The table is most powerful when integrated with the clinical framework from Part [X]:
- Chart review (Part [X]): Identify medical conditions, recent changes, medications
- Red flag recognition (Part [X]): Note age >40, atypical features, temporal associations
- Table consultation (this part): Determine which psychiatric symptoms are associated with identified medical conditions
- Targeted interview: Ask specifically about symptoms the table suggests may be present
- Diagnostic workup: Order studies from the “Associated Work-Up” column
- Specialist collaboration: Coordinate with relevant medical/surgical specialists
- Formulation: Integrate medical and psychiatric factors into unified diagnostic understanding
- Treatment planning: Address medical contributors while providing appropriate psychiatric care
Special Considerations by Disease Category
Neurological Disorders
Neurological conditions are particularly likely to present with psychiatric symptoms, as they directly affect brain structure and function. Multiple sclerosis, for example, is associated with depression, anxiety, mania, psychosis, personality changes, mood lability, OCD, and sleep disorders. The extensive psychiatric phenomenology reflects the diverse locations and mechanisms of CNS demyelination. When evaluating psychiatric symptoms in neurological patients, maintain close coordination with neurology and recognize that psychiatric symptoms may be the initial or most prominent manifestation of neurological disease progression.
Endocrinopathies
Thyroid, adrenal, and parathyroid disorders are classic causes of psychiatric symptoms and are among the most important to identify because they are highly treatable. Hyperthyroidism can present with mania indistinguishable from primary bipolar disorder. Hypothyroidism commonly causes depression that may not fully respond to antidepressants without thyroid replacement. Cushing’s syndrome (hypercortisolism) can produce the full range of mood, anxiety, psychotic, and cognitive symptoms. Always screen for endocrine disorders in new-onset psychiatric symptoms, particularly when physical signs suggest endocrine dysfunction.
Autoimmune and Inflammatory Disorders
Systemic lupus erythematosus, rheumatoid arthritis, and other collagen vascular diseases produce psychiatric symptoms through neuroinflammation, autoantibody effects on CNS, cerebrovascular complications, and medication effects (particularly corticosteroids). The psychiatric manifestations may precede systemic symptoms or may be the presenting feature of disease flare. Collaboration with rheumatology is essential, as immunosuppressive treatment may improve psychiatric symptoms when they result from active autoimmune disease.
Metabolic and Nutritional Disorders
Electrolyte imbalances and vitamin deficiencies are common, readily identifiable, and often rapidly reversible causes of psychiatric symptoms. Vitamin B12 deficiency, for example, can produce depression, mania, psychosis, and cognitive impairment, sometimes before hematological changes are evident. Hyponatremia can present with confusion, psychosis, and mood changes that resolve completely with sodium correction. Always include basic metabolic panel, thyroid function, and B12 in the workup of new psychiatric symptoms, particularly in elderly patients and those with medical comorbidities.
Medication-Induced Symptoms
The table includes a comprehensive section on psychiatric symptoms caused by medications commonly prescribed for medical conditions. Corticosteroids, beta-blockers, interferons, and many other agents can produce or exacerbate psychiatric symptoms. When a patient develops new psychiatric symptoms shortly after medication initiation or dose change, strongly suspect medication contribution. The temporal association (symptoms emerging days to weeks after medication start) is the key diagnostic clue. In many cases, symptoms resolve with medication discontinuation or dose reduction.
Sleep Disorders
Sleep disorders have bidirectional relationships with psychiatric symptoms. Obstructive sleep apnea, insomnia, and circadian rhythm disorders can cause or worsen depression, anxiety, and cognitive impairment. Conversely, psychiatric disorders disrupt sleep architecture. The table documents not only which sleep disorders are associated with psychiatric symptoms, but also includes emerging evidence of causal relationships. For example, insomnia increases risk for subsequent development of major depressive disorder, anxiety disorders, and bipolar disorder through shared genetic risk and Mendelian randomization studies. Treating sleep disorders may improve psychiatric outcomes.
Documentation and Communication
When you identify a medical condition that may be contributing to psychiatric symptoms, document:
- The specific medical diagnosis and its current status (controlled, active, worsening)
- Which psychiatric symptoms from the table are associated with that condition
- The temporal relationship (did symptoms begin or worsen with medical diagnosis/treatment?)
- Results of diagnostic workup from the “Associated Work-Up” column
- Your clinical reasoning about whether the medical condition is contributing to psychiatric symptoms
- Coordination with medical specialists regarding treatment of underlying condition
- Plan for reassessing psychiatric symptoms after medical treatment
Example documentation: “Patient is a 45-year-old woman with hypothyroidism (TSH 8.2, elevated) presenting with depression, fatigue, and cognitive complaints. Per literature, hypothyroidism is commonly associated with depression, anxiety, panic, and psychosis. Temporal relationship: patient’s levothyroxine was decreased 2 months ago by PCP, and depressive symptoms emerged shortly thereafter. Physical exam notable for bradycardia and delayed reflexes, consistent with hypothyroidism. Assessment: Depression likely secondary to inadequately treated hypothyroidism. Plan: Coordinated with PCP to increase levothyroxine. Will reassess mood after euthyroid state achieved (4-6 weeks). Holding antidepressant trial pending thyroid optimization. If mood symptoms persist after TSH normalization, will initiate SSRI.”
This documentation:
- Links clinical findings to literature on hypothyroidism and psychiatric symptoms
- Establishes temporal relationship
- Provides clear rationale for treatment approach
- Sets expectations for follow-up assessment
Why This Information Matters
Medical illness and psychiatric symptoms are inextricably linked. The artificial separation between “medical” and “psychiatric” care often leads to fragmented evaluation, missed diagnoses, and suboptimal treatment. This table represents an integration of medical and psychiatric knowledge, recognizing that the brain—the organ of psychiatric illness—is profoundly affected by systemic disease, metabolic derangements, inflammatory processes, and pharmacological agents.
For diagnostic accuracy: The table prevents diagnostic anchoring. When we see depression, we should not reflexively diagnose major depressive disorder without considering whether hypothyroidism, anemia, chronic hepatitis, or numerous other medical conditions might be causative or contributory. The table makes the full differential diagnosis visible and actionable.
For patient safety: Many medical conditions presenting with psychiatric symptoms are dangerous if left untreated. Hyperthyroidism can progress to thyroid storm. Hyponatremia can cause seizures and brain herniation. Hepatic encephalopathy can progress to coma. Recognizing psychiatric symptoms as manifestations of medical emergencies can be life-saving.
For treatment effectiveness: Psychiatric symptoms secondary to medical illness often do not respond adequately to psychiatric treatment alone. Antidepressants will not effectively treat depression caused by untreated hypothyroidism. Anxiolytics will not control panic-like symptoms caused by temporal lobe epilepsy. Antipsychotics may worsen confusion caused by anticholinergic medications. Identifying and treating the underlying medical cause is often more effective than treating psychiatric symptoms directly.
For prognostication: When psychiatric symptoms are caused by medical illness, prognosis depends on treating the medical condition. Some medically-caused psychiatric symptoms resolve completely with appropriate medical treatment (hypothyroidism-induced depression, B12 deficiency psychosis). Others may be chronic but stabilize with medical management (psychiatric symptoms of well-controlled epilepsy). Understanding the medical cause allows accurate prognostication and realistic expectation-setting with patients and families.
For reducing health disparities: Patients with severe mental illness have significantly elevated rates of medical comorbidity and die 10-20 years younger than the general population, largely from preventable medical conditions. Systematically screening for medical causes of psychiatric symptoms and facilitating medical care for patients with mental illness is an equity issue and a public health imperative.
The practice of psychiatry requires medical expertise. This table embodies that principle, serving as a bridge between psychiatric phenomenology and medical pathophysiology. Use it as a clinical tool, a teaching resource, and a reminder that every psychiatric symptom demands consideration of its medical context.
