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Assessment and Management of Psychiatric Disorders in Medically Ill In-patients
1. The Field: Consultation-Liaison (C-L) Psychiatry
Consultation-Liaison Psychiatry (formerly called Psychosomatic Medicine, renamed by the American Board of Psychiatry and Neurology in 2017) is the subspecialty dedicated to diagnosing and treating psychiatric disorders in patients with complex medical conditions. It was formally recognized as a subspecialty by the American Board of Medical Specialties in 2003 (as Psychosomatic Medicine, renamed C-L Psychiatry in 2017).
Mental health conditions occur in 30-60% of patients depending on the chronic medical condition involved, yet most go unrecognized and untreated. Patients with co-occurring psychiatric and medical conditions are two to three times more costly to treat than those without psychiatric comorbidities. - Kaplan & Sadock's Comprehensive Textbook of Psychiatry
2. Categories of Clinical Problems
The C-L psychiatrist encounters problems across a wide spectrum:
| Type of Clinical Problem | Examples |
|---|
| Psychiatric symptoms secondary to a medical condition | Delirium, dementia |
| Psychiatric symptoms as a reaction to medical illness or treatments | Anxiety related to chemotherapy; depression after limb amputation |
| Psychiatric complications of medical conditions/treatments | Mania secondary to corticosteroid treatment |
| Psychological factors contributing to medical symptoms | Somatic symptom disorders |
| Medical complications of psychiatric conditions or treatment | Neuroleptic malignant syndrome; acute alcohol/substance withdrawal |
| Co-occurring (independent) medical and psychiatric conditions | Recurrent depression during cancer treatment; schizophrenia with end-stage renal disease |
| Psychiatric/psychosocial assessment | Decision-making capacity evaluation; pre-transplantation evaluation |
From Table 27.1-3, Kaplan & Sadock's Comprehensive Textbook of Psychiatry
3. Assessment (Evaluation Process)
3a. Standard Approach
The psychiatric assessment in the medical setting includes all standard components plus a specific focus on the medical context. Key elements:
- Full psychiatric history: past history, family history, developmental history, review of systems
- Medical history and current treatments: reviewed and documented thoroughly
- Full mental status examination (MSE): level of consciousness, attention, concentration, memory, executive function, language, praxis, mood, affect, perception, judgment, and insight
- Cognitive screening: The Mini-Mental State Examination (MMSE) or Montreal Cognitive Assessment (MoCA) provides a baseline score for serial retesting, especially when delirium or dementia is a concern
- Targeted neurologic and physical examinations as indicated
- Laboratory work: Basic chemistry, hematology, cardiovascular workup, thyroid function, liver function, vitamin B12, folate, toxicology, syphilis serology, and HIV testing
- Neuroimaging/other: CT or MRI brain, EEG, or lumbar puncture when clinically indicated
3b. Special Steps in the Medical Setting
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Communicate with the referring clinician first - The reason for consultation is often unclear; understanding the team's concerns can reveal the patient's behavior (e.g., over- or under-use of pain medication), frustration with a difficult patient, or specific concerns not captured in the referral note.
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Obtain collateral information - From family members and other healthcare providers (including existing mental health professionals) to establish prior psychiatric history and inform discharge planning.
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Adapt the interview to the patient's medical status - Patients may be experiencing pain, discomfort, distraction from medical problems, or cognitive compromise. The interview should be focused on the consultation question when needed.
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Understand the patient's illness experience - Developmental and personal history, key dynamic conflicts, personality traits, coping strategies, and defense mechanisms help make the patient's response to illness comprehensible and guide both psychotherapy and advice to the primary team.
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Write a synthesizing report - Include specific recommendations for additional evaluation and intervention, limited to what is medically necessary. Accompany with a discussion with the referring physician. - Kaplan & Sadock's Comprehensive Textbook of Psychiatry, p. 6791-6792
4. Common Psychiatric Disorders and Their Management
4a. Delirium
Delirium is the most common psychiatric emergency in medically ill in-patients. Key principles:
Non-pharmacological first-line measures:
- Treat the underlying medical cause (infection, metabolic disturbance, medication toxicity, withdrawal)
- Reorientation, sleep-wake cycle restoration, minimizing sedating medications, removing unnecessary catheters/restraints, ensuring adequate hydration and nutrition
- Involve family members for reorientation
Pharmacological management:
- Benzodiazepines are avoided (except in alcohol or sedative-hypnotic withdrawal) because they can exacerbate delirium and increase fall risk. The exception: alcohol withdrawal delirium (delirium tremens) is treated with benzodiazepines (e.g., lorazepam infusion/bolus, tapered slowly).
- Antipsychotics are the most studied class. Review evidence in non-ICU patients shows unclear efficacy on delirium severity/duration/mortality; however, expert consensus supports a limited role for patients with severe distress, agitation, or psychotic symptoms.
- Haloperidol remains the agent of choice for behavioral/psychotic symptoms in delirium due to:
- Availability (oral and IV routes)
- Minimal hypotension
- Not anticholinergic
- Does not depress respiration
- Does not impair glucose regulation
- QTc monitoring required: Obtain baseline QTc before starting; do not use IV haloperidol if QTc ≥450 ms (male) or ≥470 ms (female); discontinue if QTc increases >25% above baseline
- Dosing in older adults: 0.25-0.5 mg IV every 8 hours scheduled + 0.25-0.5 mg IV every 6 hours as needed; oral doses are higher (0.5-1 mg). Continue for 2-3 days then taper over 2-3 days once agitation resolves
- Atypical antipsychotics (risperidone, olanzapine, quetiapine) are equally effective to haloperidol for agitation/psychosis in delirium and are generally well tolerated
- Dexmedetomidine (alpha-2 agonist) in mechanically ventilated ICU patients: shown to produce more delirium/coma-free days than lorazepam (7 vs. 3 days, p=0.01)
- Limited evidence for melatonin, ramelteon, or cholinesterase inhibitors - Kaplan & Sadock's Comprehensive Textbook of Psychiatry, p. 12887-12888
For acute agitation in unselected ill patients (uncertain etiology - psychiatric disorder, delirium, or substance-induced):
- Antipsychotic alone or combined with a benzodiazepine is used
- Classic IM combination: haloperidol 5 mg + lorazepam 2 mg
- Monotherapy with lorazepam, midazolam, droperidol, or haloperidol is recommended first; add benzodiazepine-antipsychotic combination if monotherapy fails - Kaplan & Sadock's Comprehensive Textbook of Psychiatry, p. 9820
4b. Depression in the Medically Ill
- Highly prevalent (10-40%) in medical in-patients; often underdiagnosed because somatic symptoms of depression overlap with those of physical illness
- Screening tools validated for medically ill patients: Hospital Anxiety and Depression Scale (HADS) is preferred because it de-emphasizes somatic items
- Studies using HADS have identified 10-15% of medical in-patients who would qualify for prophylactic treatment
- Management:
- Psychotherapy: Cognitive-behavioral therapy (CBT), supportive therapy, and problem-solving therapies are effective; goals are adapted to the illness (e.g., addressing barriers to treatment adherence in diabetes, loss of role/function in arthritis, existential concerns in terminal illness)
- Pharmacotherapy: SSRIs are first-line (consider drug-drug interactions, hepatic function, risk of serotonin syndrome). Must consider side effect profiles specific to the medical condition (e.g., weight gain, cardiac risk, QTc prolongation)
- ECT: May be treatment of choice for severely depressed, suicidal, or pregnant patients who cannot take medications, or in geriatric/medically ill patients where rapid response is needed
- Interventions for depression in diabetic patients have shown both reduced depressive symptoms and reduction in medical costs of care
4c. Anxiety in the Medically Ill
- Anxiety is often a reaction to the medical condition or its treatments (e.g., chemotherapy-related anticipatory anxiety)
- Must be distinguished from anxiety secondary to a medical cause (e.g., hyperthyroidism, pheochromocytoma, cardiac arrhythmia, respiratory disease, medication side effects)
- Management:
- Treat underlying medical cause first
- Psychosocial interventions: CBT, relaxation techniques, mindfulness-based approaches, supportive therapy
- Pharmacotherapy: Short-term benzodiazepines (use with caution in respiratory disease, elderly, or delirium-prone patients); SSRIs/SNRIs for persistent anxiety; buspirone
- Education of the patient and family about the medical condition reduces anxiety significantly
4d. Somatic Symptom and Related Disorders
- Psychological factors that contribute to or worsen medical symptoms
- Management involves avoiding unnecessary investigations (while ensuring adequate evaluation), consistent communication with a single treating physician, psychotherapy (particularly CBT), and judicious use of antidepressants for comorbid depression/anxiety
4e. Primary Psychiatric Disorders Managed in the Medical Setting
(e.g., schizophrenia, bipolar disorder in a medically ill patient)
- Continue effective psychiatric medications where medically feasible
- Adjust for organ dysfunction (renal, hepatic)
- Watch for drug-drug interactions with medical treatments (e.g., lithium toxicity with NSAIDs or diuretics; antipsychotic effects on QTc, metabolic syndrome, or tardive dyskinesia with prolonged use)
- Increased awareness of antipsychotic risks in patients with dementia (increased mortality)
5. Psychopharmacology in the Medically Ill: Special Considerations
When prescribing psychotropic medications to medically ill patients, the following must always be evaluated:
| Factor | Key Issues |
|---|
| Drug-drug interactions | Most psychotropics are hepatically metabolized (CYP450 system); check interactions with all medical drugs |
| Liver function | Reduced first-pass metabolism, altered drug distribution |
| Renal function | Affects lithium, certain antipsychotics, some antidepressants |
| Cardiovascular effects | QTc prolongation (haloperidol, TCAs, many antipsychotics), orthostatic hypotension |
| Metabolic effects | Weight gain, hyperglycemia (atypical antipsychotics), dyslipidemia |
| Contraindications | e.g., bupropion in seizure disorder, lithium in renal failure, MAOIs with many medications |
| Special populations | Elderly (reduced doses), renal/hepatic impairment, pregnancy |
6. Psychosocial Interventions
Every major modality has been used in C-L psychiatry:
- Dynamic/insight-oriented therapy: Addressing illness meaning, coping with disability
- Supportive therapy: Providing emotional support, normalizing distress
- Cognitive-behavioral therapy (CBT): Challenging maladaptive illness beliefs, behavioral activation
- Family and group therapy: Addressing caregiver burden, peer support for chronic illness
- Goals vary by disease stage:
- Addressing changes in role and function (all chronic conditions)
- Coping with pain and physical changes (arthritis, chronic pain)
- Addressing death and dying (terminal cancer, advanced heart failure)
- Improving treatment adherence (diabetes, HIV, transplant)
An extensive body of research has demonstrated that psychosocial interventions improve quality of life and psychiatric conditions; some evidence suggests positive impacts on treatment adherence and even medical outcomes. - Kaplan & Sadock's Comprehensive Textbook of Psychiatry, p. 6793
7. Capacity Assessment and Special Evaluations
C-L psychiatrists are frequently asked to evaluate:
- Decision-making capacity: Does the patient understand, appreciate, reason, and communicate a choice? Capacity is decision-specific and fluctuates (unlike competence, which is a legal determination)
- Pre-transplantation psychological evaluation: Assessing psychiatric stability, substance use, adherence potential, social support
- Quality of life and end-of-life symptom management in terminally ill patients
8. Service Models
| Model | Description |
|---|
| Traditional C-L | Psychiatrist responds to individual consultations on the inpatient unit |
| Colocation (PCBH) | Mental health provider embedded in a medical clinic; improves access but limited population-level impact |
| Collaborative Care Model (CoCM) | Systematic approach: behavioral health care manager + consulting psychiatrist + PCP work together; has the strongest RCT evidence for improving quality of care and outcomes for depression, anxiety, and substance use conditions in medical settings; reimbursement approved in 2017 |
Key Takeaway
The assessment of psychiatric disorders in medically ill in-patients requires an integrated approach: thorough psychiatric and medical history, MSE with cognitive assessment, appropriate diagnostic workup, and clear communication with the primary team. Management combines targeted pharmacotherapy (adapted for drug interactions, organ function, and medical comorbidities), evidence-based psychosocial interventions, and liaison work with the treating team. Delirium demands prompt identification and treatment of the underlying medical cause; depression and anxiety require validated screening tools suited to medically ill populations; and all psychotropic prescribing must weigh the significant pharmacokinetic and pharmacodynamic differences in this population.
Sources:
- Kaplan & Sadock's Comprehensive Textbook of Psychiatry - Chapter 27.1: The Clinical Practice and Evaluation Process and Treatments in C-L Psychiatry (pp. 6790-6795)
- Kaplan & Sadock's Comprehensive Textbook of Psychiatry - Chapter 55.3g: Delirium pharmacotherapy (pp. 12887-12888)
- Kaplan & Sadock's Comprehensive Textbook of Psychiatry - Chapter on Agitation in Medically Ill Patients (pp. 9820-9821)
- Kaplan and Sadock's Synopsis of Psychiatry - Section 25.1: Consultation-Liaison Psychiatry (p. 2445)