II. Epidemiology
-
Prevalence: 0.3 to 0.7% worldwide across all ethnicities, nationalities (up to 1% in U.S.)
- Most common Psychotic Disorder
- However, in U.S., black patients are disproportionately diagnosed over non-hispanic whites
- Gara (2012) Arch Gen Psychiatry 69(6): 593-600 [PubMed]
- Gender: Equal among men and women
- Men present ages 18 to 25 years old
- Women present age 25 to mid-30s and also after age 40 years old
- Children rarely present age <15 years (but case reports in children as young as 5 years old)
- Age
- Age onset in transition from Adolescence to Adulthood
- Men present earlier than women (see above)
- First attack usually occurs before 40 years old (although some women may present later)
III. Pathophysiology
- Polygenic Threshold Model
- Combination of genetic predisposition and environmental factors
- Heredity Concordance
- Monozygotic twins: 69%
- Dizygotic: 13%
- Schizoid Personality Disorder
- Associated with Schizophrenia (RR=50)
- Protective factors in the family environment
- Uncommon criticism
- Straightforward communication
- Altered Neurotransmission
- Glutamate, Serotonin and Dopamine have altered activity in the Hippocampus, Midbrain, corpus striatum and prefrontal cortex
- Increased and dysregulated Dopamine exacerbates positive symptoms (Antipsychotics primarily reduce Dopamine)
- Other factors
- Inflammatory Cytokines
- Endocrine, Physical associations are only coincidental
- Neurohumoral: Super sensitive receptors
- Neurophysiologic: Spiking or slow waves at Hippocampus
IV. Risk Factors
-
Family History or Genetic Risk Factors (most significant risk)
- However, most patients with Schizophrenia have no Family History
- Schizophrenia confers an increased risk of mental illness to family members
- Increased risk includes Schizophrenia, schizoaffective disorder, Bipolar Disorder, Major Depression
- Monozygotic twin: 50% lifetime Incidence
- Dizygotic twin: 17% lifetime Incidence
- First degree relative: 6-17% lifetime Incidence
- Lewis (2000) Neuron 28:325-34 [PubMed]
- Environmental Risk Factors
- Obstetric complications (e.g. neonatal hypoxic events)
- Maternal or early childhood infections (e.g. Toxoplasmosis, Rubella, HSV 2, Influenza)
- Maternal or early childhood nutritional deficiency (e.g. Folic Acid Deficiency, Iron Deficiency, Vitamin D Deficiency)
- Early childhood CNS Infection
- Advanced paternal age (over 55 years old)
- Childhood Trauma
- Marijuana (or Cannabis) use
- Excess Stimulation of Cannabinoid Receptor 1 may trigger increased Dopamine release
- Risk increases with degree of consumption
- Arseneault (2002) BMJ 325(7374): 1212-3 [PubMed]
- Marconi (2016) Schizophr Bull 42(5): 1262-9 [PubMed]
V. Types
- See Psychosis Types
VI. History
VII. Symptoms: Phases
- Premorbid Phase
- Typically asymptomatic
- Prodromal phase
- Social withdrawal
- Loss of interest in school or work
- Hygiene and grooming deteriorate
- Angry outbursts
- Unusual behavior
- Syndromic Phase
- Chronic or Residual Phase
- Variable depending on Medication Compliance and social support
VIII. Signs
- See Psychosis Exam
IX. Labs
- See Psychosis Labs
- Indicated to exclude other causes in the Psychosis Differential Diagnosis
X. Differential Diagnosis
XI. Diagnosis
- See Schizophrenia Diagnosis
- Schizophrenia is a clinical diagnosis
- Lab and imaging are solely indicated to exclude other possible causes in the differential diagnosis
- Schizophrenia has no specific lab or imaging findings
XII. Associated Conditions
- Anxiety Disorder
- Panic Disorder
- Postraumatic Stress Disorder
- Obsessive Compulsive Disorder
XIII. Management: General
- See Psychosis for acute management
- See Neuroleptic Medications
- Urgent psychiatry referral
- Admission to a controlled setting is preferred for acute Psychosis
- Medication initiation
- Patients should be offered medication management at the time of initial diagnosis
- In the primary care setting, consult with a psychiatrist if considering the start of an Antipsychotic
- Medication adverse effects and monitoring requirements should be discussed prior to starting Antipsychotics
- Do not use a loading dose of Antipsychotics
- Response to first 2-4 weeks of therapy is predictive of longterm response
- Maximal effect may not be evident for months after initiating therapy
- Medications help patients return to baseline functioning (esp. social), quality of life and prevent longterm Disability
- Schizophrenia medication management is intended for lifelong, continuous use
- Relapse and decompensation occurs when medications are stopped
- Adjunctive therapy (improves quality of life, relapse rates, Medication Compliance)
- Cognitive Behavioral Therapy for Psychosis should be offered to patients with Schizophrenia
- Acceptance and Mindfulness-based therapy
- Meta-cognitive therapy
- Positive psychology interventions
- Cognitive remediation training
- Decreases positive symptoms
- Improves concentration, memory and problem solving
- Other measures
- Family interventions
- Social skill training
- Electroconvulsive Therapy
- Weekly telephone-based care management
- Decreases rehospitalization rates
- Cognitive Behavioral Therapy for Psychosis should be offered to patients with Schizophrenia
XIV. Management: Pitfalls
-
Atypical Antipsychotics offer no significant effectiveness benefit over first generation agents
- Select agents based on which adverse effects are expected to be least tolerated
- First generation agents cause Extrapyramidal Side Effects most significantly
- Second generation agents (atypicals) cause weight gain and metabolic changes most significantly
- Manage metabolic adverse effects including weight gain (e.g. Metformin, Topiramate)
- Monitor and manage Tardive Dyskinesia
- Patients stop their medications frequently
- Patients who stopped meds within 18 months: 74%
- Relapse is very high risk after stopping medications (within 1-2 years)
- Lieberman (2005) New Engl J Med 353:1209-23 [PubMed]
- Delay in treatment significantly worsens prognosis
- Best outcomes are with early diagnosis
- Wyatt (1997) Psychol Med 27:261-8 [PubMed]
- Monotherapy with a single Antipsychotic may be preferred
- However more than 50% of Schizophrenia patients may be on more than one Antipsychotic
- Consider adjunctive use of Antidepressants or mood stabilizers where appropriate
- Consider switching to a different Antipsychotic after an adequate duration and dose
- Consider Clozapine in treatment resistant Schizophrenia (review Clozapine adverse effects)
- Consider long-acting injectables when Medication Compliance is low
- If a second Antipsychotic is required, consider an agent that balances the adverse effects of the first
- Barbui (2009) Schizophr Bull 35(2):458-68 [PubMed]
XV. Prognosis
- High risk of Suicide
- Lifetime risk: 5-10% (13 fold higher than the general population)
- Increased risk with Auditory Hallucinations, Delusions, Substance Abuse or prior Suicide attempt
- Higher rate of overall mortality
- Death rates are 2-4 fold higher than the general population
- Cardiovascular disease (RR 2-3, premature and accelerated) is the most common cause of death in Schizophrenia
- Increased risks of cardiovascular disease, respiratory disease, stroke, cancer and Venous Thromboembolism
- Encourage Tobacco Cessation
XVI. References
- (2000) DSM IV, American Psychiatric Association, p. 297-343
- (2013) DSM V, American Psychiatric Association, p. 99
- Arnold (2024) Am Fam Physician 109(5): 482-3 [PubMed]
- Crawford (2022) Am Fam Physician 106(4): 388-96 [PubMed]
- Freedman (2003) N Engl J Med 349:1738-49 [PubMed]
- Holder (2014) Am Fam Physician 90(11): 775-82 [PubMed]
- Lewis (2000) Neuron 28:325-34 [PubMed]
- Schultz (2007) Am Fam Physician 75:1821-9 [PubMed]