Psychosis Differential Diagnosis

Aka: Psychosis Differential Diagnosis, Psychosis Cause, Primary psychosis, Secondary Psychosis, Organic Psychosis

1. See Also
   1. Psychosis
   2. Psychosis Symptoms
   3. Psychosis Exam
   4. Psychosis Types
   5. Drug Induced Psychosis
   6. Psychosis Diagnostic Testing
   7. Schizophrenia
   8. Schizophrenia Diagnosis
   9. Delirium
2. Differential Diagnosis: Psychiatric Conditions
   1. Schizophrenia
      1. Psychosis for >6 months, with an acute phase lasting one month or more
   2. Schizophreniform Disorder
      1. Psychosis Symptoms for >1 month and <6 months
      2. Consistent with Schizophrenia, but <6 months duration
   3. Schizoaffective disorder
      1. Psychosis with active phase symptoms for 1 month with concurrent Mood Disorder
      2. No Alcohol Dependence
   4. Schizotypal Personality Disorder
      1. Persistent personality features that do not meet criteria for Schizophrenia and related conditions
   5. Delusional disorder
      1. Non-bizarre Delusions without Hallucinations for 1 month
      2. No Alcohol Dependence
   6. Brief Psychotic Disorder
      1. Delusions, Hallucinations and Disorganized Speech or behavior for at least one day, but less than one month
   7. Shared Psychotic Disorder
      1. Folie a deux
   8. Autism spectrum disorder (or communication disorders)
      1. Social interaction deficits with repetitive and restricted behaviors
   9. Bipolar I Disorder
      1. Psychosis with manic phase
      2. Presents with 7 days or more of elevated or expansive mood, decreased sleep, goal directed activity
   10. Major Depression
       1. Psychotic depression or drug resistant depression with Psychosis limited to times of Mood Disorder
   11. Postpartum Psychosis
       1. Brief Psychotic Disorder onset during pregnancy or within 4 weeks of delivery
   12. Posttraumatic Stress Disorder
       1. Psychotic symptoms related to reaction to precipitating event
   13. Obsessive Compulsive Disorder and Body Dysmorphic Disorder
       1. Significant Obsessions, compulsions or preoccupations related to body or associated repetitive behaviors
3. Differential Diagnosis: Organic Conditions (Secondary Psychosis)
   1. Drug Induced Psychosis
      1. See Drug Induced Psychosis
      2. Medication toxicity
      3. Substance Abuse
   2. Medications and Antibiotics (Antibiomania)
      1. Clarithromycin
      2. Ciprofloxacin
      3. Corticosteroids
   3. Electrolyte disturbance
      1. Hyponatremia
      2. Hypercalcemia
      3. Hypocalcemia
      4. Hypomagnesemia
   4. Endocrine and Metabolic disorders
      1. Hypoglycemia (or Hyperglycemia)
      2. Hypothyroidism or Hyperthyroidism
      3. Cushing Syndrome
      4. ACTH Producing Lung Cancer
      5. Hyperparathyroidism
      6. Acute intermittent porphyria
      7. Adult onset Tay-Sachs
      8. Wilson Disease
   5. Infectious disorders
      1. Sepsis
      2. HIV Infection
      3. Syphilis (neurosyphillis)
      4. Encephalitis
   6. Neurologic disorders
      1. Hepatic Encephalopathy
      2. Delirium
      3. Dementia (e.g. Alzheimer Disease, Lewy Body Dementia)
      4. Tic Disorder
      5. Huntington's Chorea
      6. Temporal Lobe Epilepsy (or other Seizure Disorder)
      7. Brain Tumor
      8. Multiple Sclerosis
      9. Parkinson Disease
   7. Miscellaneous conditions
      1. Vitamin B1 Deficiency (Thiamine deficiency)
      2. Vitamin B3 Deficiency (Niacin Deficiency)
      3. Vitamin B12 Deficiency
      4. Systemic Lupus Erythematosus
      5. Porphyria
      6. ICU Psychosis
      7. Sleep Deprivation (e.g. Sleep Apnea)
   8. Malignancy
      1. Ovarian Teratoma
      2. Small Cell Lung Cancer
      3. Paraneoplastic limbic Encephalitis
4. References
   1. (2013) DSM V, American Psychiatric Association, p. 99
   2. (2000) DSM IV, American Psychiatric Association, p. 297-343
   3. Freedman (2003) N Engl J Med 349:1738-49 [PubMed]
   4. Griswold (2015) Am Fam Physician 91(12):856-63 [PubMed]
   5. Holder (2014) Am Fam Physician 90(11): 775-82 [PubMed]
   6. Schultz (2007) Am Fam Physician 75:1821-9 [PubMed]