What is the diagnosis and treatment plan for a 56-year-old patient with a history of Bipolar 1 Disorder, presenting with catatonia, psychosis, and substance use disorders?

Primary Diagnosis and Differential Diagnoses

This patient has catatonia secondary to Bipolar I Disorder with acute psychotic exacerbation, complicated by polysubstance use (cannabis, alcohol, methamphetamine). The positive lorazepam response by day 3 confirms the catatonia diagnosis, and the documented history of Bipolar I Disorder with seven prior involuntary admissions establishes the underlying psychiatric etiology 1, 2.

Primary Diagnosis

Catatonia Associated with Bipolar I Disorder (F20.2 + F31.2)

The diagnosis is supported by:

• Classic catatonic features: mutism, stupor, staring, withdrawal, minimal environmental responsiveness, and thought blocking—all documented on admission 1, 2
• Positive lorazepam challenge: Clinical improvement with verbalization by day 3 of lorazepam treatment is diagnostic and therapeutic confirmation 1, 3, 4
• Underlying Bipolar I Disorder: Seven prior involuntary psychiatric admissions for psychotic episodes with grave disability establish chronic severe mental illness 5
• Acute psychotic exacerbation: Disorganized behavior, poverty of speech, internal preoccupation, and inability to care for self indicate active psychosis 6, 1

Critical Differential Diagnoses to Exclude

1. Malignant Catatonia (Life-Threatening Emergency)

• Must monitor for: autonomic instability (temperature dysregulation, blood pressure changes, tachycardia, tachypnea) which would indicate progression to malignant catatonia 2
• Current vital signs show elevated BP (requiring monitoring) but no frank autonomic instability yet 2
• Mortality risk: Malignant catatonia is fatal without treatment—requires immediate escalation to ECT if autonomic signs develop 5, 2

2. Neuroleptic Malignant Syndrome (NMS)

• Key distinguishing features: NMS presents with rigidity, hyperthermia, elevated creatine kinase, and recent antipsychotic exposure 2
• This patient was on quetiapine at home but labs show no evidence of NMS (normal temperature, no documented rigidity or elevated CK) 2
• Critical pitfall: NMS and malignant catatonia can be clinically indistinguishable—both require immediate benzodiazepines and consideration of ECT 5, 2

3. Substance-Induced Psychotic Disorder with Catatonia

• Active substances: THC-positive UDS, reported alcohol use ("2 quarts"), admitted methamphetamine use (though UDS negative) 6
• Against pure substance etiology: Catatonia persisting beyond acute intoxication/withdrawal window, documented chronic psychiatric history, and response pattern more consistent with primary psychiatric illness 6, 7
• Clinical reality: Polysubstance use is complicating factor but not primary driver given seven prior similar presentations 6

4. Medical/Metabolic Encephalopathy

• Ruled out by workup: Normal metabolic panel, negative infectious workup, TSH normal, no acute toxic/metabolic cause identified 6, 7
• Hyperglycemia (glucose 140 mg/dL): Reflects poorly controlled diabetes, not acute cause of catatonia 7
• Mild hypokalemia: Likely nutritional from homelessness, not sufficient to cause catatonic presentation 7

5. Delirium vs. Catatonia (Critical Distinction)

• Against delirium: No fluctuating consciousness, no acute disorientation beyond baseline psychosis, cranial nerves intact 7
• Catatonia can co-occur with delirium: This patient shows primarily catatonic features without the fluctuating consciousness characteristic of delirium 2
• Missing this distinction doubles mortality: The lorazepam response confirms catatonia as primary syndrome 7, 2

6. Autoimmune Encephalitis

• Consider if: Catatonia refractory to benzodiazepines, new-onset seizures, or atypical features develop 2
• Current assessment: No focal neurological deficits, cranial nerves intact, no seizure activity documented 2
• When to escalate workup: If no response to adequate lorazepam trial (up to 24 mg/day) or clinical deterioration 2, 8

Secondary Diagnoses Requiring Concurrent Management

• Cannabis Use Disorder: Active use confirmed by positive UDS 6
• Alcohol Use Disorder: Reported heavy drinking, though serum ethanol negative on presentation 6
• Methamphetamine Use Disorder: Admitted use per ED records 6
• Type 2 Diabetes Mellitus: Hyperglycemia (140 mg/dL) indicates poor control 5
• Hypertension: Elevated BP (requiring monitoring and treatment) 5
• Cellulitis, right hand: Currently being treated with cephalexin 5
• Grave disability with chronic homelessness: Seven involuntary admissions, unable to care for self 5

Treatment Algorithm

Immediate Management (Days 1-7)

Continue lorazepam for catatonia (currently showing response):

• Dose escalation up to 24 mg/day in divided doses if symptoms persist 1, 3, 4
• 80% of catatonia responds to benzodiazepines 3
• Monitor for respiratory depression with high doses 3

Antipsychotic management for underlying psychosis:

• Continue cross-titration from quetiapine to risperidone in preparation for long-acting injectable 1
• Avoid large initial antipsychotic doses—they increase side effects without hastening recovery 1
• Critical monitoring: Metabolic parameters (BMI monthly × 3 months then quarterly, fasting glucose and lipids at 3 months then yearly) given diabetes and antipsychotic use 5

If Catatonia Persists Beyond 7-10 Days

Escalate to ECT (electroconvulsive therapy):

• ECT is treatment of choice for: refractory catatonia, malignant catatonia, or when medications cannot be tolerated 5, 3
• ECT achieves improvement in patients who fail benzodiazepines 3
• Do not delay ECT if autonomic instability develops (malignant catatonia) 5, 2

Alternative if Lorazepam-Refractory (Research Evidence)

• NMDA antagonists (amantadine): Emerging evidence for lorazepam-refractory catatonia 8
• Stimulants (methylphenidate): Case reports show efficacy in bipolar-related catatonia after benzodiazepines fail 9

Ongoing Psychiatric Management (Weeks 2-6)

• Continue antipsychotic for 4-6 weeks before determining efficacy (therapeutic effects apparent after 1-2 weeks) 1
• If symptoms persist after adequate trial: Switch to antipsychotic with different pharmacodynamic profile 1
• Transition to long-acting injectable (risperidone LAI) given history of non-adherence and seven prior admissions 1

Substance Use Treatment

• Address polysubstance use once acute catatonia and psychosis stabilize 5
• Cannabis, alcohol, and methamphetamine use all complicate psychiatric management and increase relapse risk 6

Disposition and Long-Term Planning

• Maintain continuity of care with same clinicians for at least 18 months 1
• Include family/supports in treatment planning (though none currently identified) 1
• Address grave disability: Conservatorship evaluation, housing placement, disability benefits application 5
• Psychosocial interventions: Psychoeducation, medication adherence support, substance use treatment once stabilized 5

Critical Pitfalls to Avoid

• Don't miss malignant catatonia: Monitor vital signs closely for autonomic instability—this is a medical emergency requiring immediate ECT 5, 2
• Don't confuse catatonia with delirium: Fluctuating consciousness indicates delirium (different management); catatonia maintains awareness 7, 2
• Don't delay ECT if benzodiazepines fail: Waiting too long increases morbidity and mortality 5, 3
• Don't overlook metabolic monitoring: This patient has diabetes and is on antipsychotics—requires intensive metabolic surveillance 5
• Don't discontinue antipsychotics prematurely: Need 4-6 week trial, and given seven prior admissions, long-term maintenance is essential 1
• Don't ignore substance use: Polysubstance use significantly increases relapse risk and must be addressed for long-term stability 6