- Clinical science
Schizophrenia
Abstract
Schizophrenia is a severe psychiatric disorder characterized by chronic or recurrent psychosis. The majority of patients with schizophrenia initially experience symptoms in their 20s. The exact mechanism is unknown, but it is thought to be related to increased dopaminergic activity in the mesolimbic neuronal pathway and decreased dopaminergic activity in the prefrontal cortical pathway. Clinical features include positive psychotic symptoms, negative psychotic symptoms, cognitive impairment, catatonia, and mood symptoms. The mainstay of treatment is psychoeducation and antipsychotic therapy with dopamine antagonists.
Epidemiology
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Prevalence
- < 1%
- Lifetime risk: ♂ = ♀
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Age of onset: young adults aged 18–35
- Men: typically early 20s
- Women: typically late 20s
References:[1][2]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
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Multiple factors
- Dysregulation of dopaminergic activity
- ↓ Dopamine in prefrontal cortical pathway → negative symptoms of psychosis
- ↑ Dopamine in mesolimbic pathway → positive symptoms of psychosis
- Enlarged lateral and third ventricles
- ↓ Volume of the hippocampus and amygdala
- Altered glucose metabolism → reduced glucose in the prefrontal cortex
- Dysregulation of dopaminergic activity
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Risk factors
- Stress and psychosocial factors
- Frequent use of cannabis
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Genetics
- If any first-degree relative is affected: 12%
- If monozygotic twin is affected: 50%
- If both parents are affected: 40%
Clinical features
Schizophrenia tends to present initially with a prodrome of negative symptoms (classically social withdrawal) that precedes the positive psychotic symptoms (i.e., hallucinations and bizarre behaviors).
Features | |
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Positive symptoms of psychosis |
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Negative symptoms of psychosis |
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Cognitive symptoms |
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Mood symptoms and anxiety |
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Catatonia |
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Neurological abnormalities |
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Metabolic abnormalities |
Positive symptoms are usually an exaggeration of normal thoughts, speech, and/or behavior, while negative symptoms involve a deficit or absence of these normal processes..
Subtypes and variants
Subtypes of schizophrenia according to DSM IV (no longer in use) | |
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Characteristics | |
Disorganized schizophrenia |
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Paranoid schizophrenia |
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Catatonic schizophrenia |
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Undifferentiated schizophrenia |
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Residual schizophrenia |
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Diagnostics
Schizophrenia is a clinical diagnosis. Diagnostic criteria include (according to DSM-5):
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A) ≥ 2 of the following symptoms for ≥ 1 month (at least one of the symptoms must be from the group that is bolded)
- Delusions
- Hallucinations
- Disorganized speech
- Grossly disorganized or catatonic behavior
- Negative symptoms
- B) Symptoms must cause social, occupational, or personal functional impairment.
- C) Some sign of illness must persist for at least 6 months.
- D) Schizoaffective disorder and mood disorder with psychotic features have been ruled out.
- E) Symptoms must not be due to a medical or substance use disorder.
- F) If there is a history of autism spectrum disorder or other communication disorder beginning in childhood, the additional diagnosis of schizophrenia is made only if prominent delusions or hallucinations are also present for at least a month (or less if successfully treated).
Brain imaging of schizophrenia patients often shows cortical atrophy and enlargement of the cerebral ventricles.
References:[3]
Differential diagnoses
Psychotic disorders | |
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Schizophrenia |
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Brief psychotic disorder |
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Schizophreniform disorder |
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Schizoaffective disorder |
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Delusional disorder |
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Delusional symptoms in partner of individual with delusional disorder |
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Mood disorder with psychotic features |
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Personality disorders | |
Schizotypal personality disorder |
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Schizoid personality disorder |
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Borderline personality disorder |
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Please note: Personality disorders should not be diagnosed if there is an underlying general medical condition or substance use disorder that can better explain the symptoms. |
Mood-congruent delusions are usually seen in severe depression/mania, whereas schizoaffective disorder presents with delusions that are not congruent with the mood!
References:[1][2][4]
The differential diagnoses listed here are not exhaustive.
Treatment
- Hospitalization if acutely psychotic
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General approach: Establish therapeutic alliance when taking care of patients with delusions
- Acknowledge the patient's emotional state
- Avoid validation of delusions or confronting patients about the delusional nature of their complaints
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Antipsychotic treatment: see antipsychotics for more details
- Acute psychotic episodes: short-acting antipsychotics (e.g., olanzapine ) +/- mood stabilizer for acute mania (e.g., lithium, valproate, carbamazepine), if present
- First-line treatment: second-generation antipsychotics (atypical antipsychotics; e.g., olanzapine, risperidone, quetiapine), which are especially effective at treating positive psychotic symptoms
- Alternatively, first-generation antipsychotics (typical antipsychotics) in depot form for those at risk of poor adherence (e.g., fluphenazine, haloperidol, chlorpromazine)
- Clozapine for treatment-resistant schizophrenia: persistent positive symptoms (i.e., delusions, hallucinations, and/or disorganized speech) despite trials of ≥ 6 weeks of 2 different antipsychotics at their maximum doses
- Treatment during pregnancy: See antipsychotics.
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Psychoeducation (used as an adjunct to avoid relapse)
- Patient, family, and group psychosocial therapy and education
- Cognitive behavioral therapy
- Supportive social measures
Long-acting injectable antipsychotics should be considered for patients struggling with compliance and frequent relapses!
References:[1]
Prognosis
Schizophrenia is a progressive disease that causes significant disability, with > 30% of patients presenting with psychosocial dysfunction.
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Predictive factors for an unfavorable course of the illness
- Family history
- Earlier onset of disease
- Poor network of social support
- Being male
- Slow onset of illness
- More negative symptoms
- Concomitant substance use disorder
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Predictive factors for a favorable course of the illness
- Later onset of disease
- Being female
- Mood symptoms
- Good network of social support
- Acute onset of illness
- More positive symptoms
Patients with schizophrenia are at an increased risk of alcohol abuse, depression, violence, and suicide (∼ 50% will attempt suicide)!