Psychiatry & Family Medicine & Neurology
Schizophrenia
Schizophrenia is a severe, chronic psychiatric disorder - among the most incapacitating - characterized by a variable combination of positive psychotic symptoms (hallucinations + delusions + disorganization of thought and behavior), negative symptoms (affective blunting + alogia + avolition + anhedonia + social withdrawal) and cognitive deficits (impaired working memory + attention + executive functions), usually evolving in acute episodes interspersed with residual phases of persistent negative and cognitive symptoms. It affects around 1 % of the world's population, regardless of culture, with no significant gender predominance - although men generally develop the disease earlier (peak incidence 18-25 years) and with a more severe picture than women (peak incidence 25-35 years, with a second peri-menopausal peak). Its pathophysiology is multifactorial, involving polygenic genetic vulnerability (heritability of 80 % - concordance in monozygotic twins of 50 %) interacting with environmental factors (obstetric complications + prenatal infections + cannabis + urbanization + immigration + early adversity) to produce neurodevelopmental abnormalities neurological development characterized by deregulation of the dopaminergic (mesolimbic hyperactivity → positive symptoms + mesocortical hypoactivity → negative and cognitive symptoms) + glutamatergic (NMDA receptor hypofunction → dissociation of information processing) and serotonergic systems. Prognosis is extremely variable: one-third of patients have a favorable course with complete remission under treatment + one-third an intermediate course with relapses and partial remissions + and one-third a severe course with persistent disability - early treatment at the first psychotic episode and long-term medication compliance are the two most important modifiable prognostic factors.
Symptoms — Clinical Dimensions
- Positive symptoms (excess or distortion of normal functions): auditory hallucinations (most frequent—voices commenting on actions + voices conversing with each other + voices giving commands) + visual hallucinations + tactile + olfactory (less frequent) + delusions (persecution++ + reference + grandeur + control + influence + jealousy + erotomania) + disorganized thought process (tangentiality + derailment + neologisms + thought fragmentation) + disorganized or catatonic behavior
- Negative symptoms (decrease or absence of normal functions): Emotional blunting (reduced emotional facial expression + monotonous voice) + alogia (poverty of speech + delayed responses) + avolition (inability to initiate activities) + anhedonia (inability to experience pleasure) + social withdrawal + abulia + poor hygiene + negative symptoms are the most debilitating in daily life and the least well-treated by antipsychotics
- Cognitive deficits Working memory problems + attention and vigilance deficits + executive function disorders + slowed information processing + social cognition deficits (theory of mind) + cognitive deficits often precede psychosis and persist during symptomatic remission → main cause of functional impairment
- Disorganization symptoms: Disorganized speech + severely disorganized behavior + catatonia (stupor + rigidity + bizarre postures + echophenomena) + inappropriate affect
DSM-5 Diagnostic Criteria
- Criterion A — 2 or more symptoms for ≥ 1 month: delusional ideas + hallucinations + disorganized speech + grossly disorganized or catatonic behavior + negative symptoms + at least one of the first 3 must be present
- Criterion B — Social or occupational dysfunction: The level of functioning in work, relationships, or self-care is significantly lower than it was before the onset of the disorder.
- Criterion C — Duration: continuous signs of the disorder for at least 6 months (including at least 1 month of active Criterion A symptoms) + may include prodromal and residual phases
- Criterion D - Exclusion of Schizoaffective Disorder and Bipolar Disorder
- Criterion E - Exclusion of a general medical condition or substance
- Criterion F — Relationship with ASD: if a history of autism spectrum disorder — diagnosis of schizophrenia only if prominent hallucinations or delusions for ≥ 1 month
Differential diagnosis
| Diagnosis | Distinctive elements |
|---|---|
| Schizoaffective disorder | Affective episodes (major depression + mania) concomitant with psychotic symptoms + represent a substantial portion of the total duration |
| Bipolar disorder with psychotic features | Psychotic symptoms confined to mood episodes (mania + depression) + euthymia between episodes |
| Major depressive disorder with psychotic features | Mood-congruent psychosis (depressive themes) + confined to depressive episodes |
| Substance-induced psychosis | Cannabis + cocaine + amphetamines + psilocybin + ketamine → psychosis occurring during intoxication or withdrawal → resolution upon cessation of the substance (but may trigger true schizophrenia in vulnerable individuals) |
| Organic psychosis (medical condition) | Temporal lobe epilepsy + cerebral lupus + autoimmune encephalitis (anti-NMDAR) + neurosyphilis + Wilson's disease + hyperglycemia + hyponatremia + severe hypothyroidism → laboratory workup + EEG + brain MRI + systematic neuronal antibodies in the first psychotic episode |
| Schizotypal personality disorder | No frank psychosis + mild perceptual distortions + magical thinking + chronic social isolation without an acute episode |
Assessment after the first psychotic episode
- Biological tests : Kidney function tests + ionogram + blood glucose + creatinine + liver panel + TSH + calcium + B12 + folate + serologies (HIV + syphilis + hepatitis) + urine drug screen (cannabis + cocaine + amphetamines + opioids) + blood copper + ceruloplasmin if young patient (Wilson's disease)
- Anti-neuronal antibodies Systematic testing for anti-NMDAR, anti-LGI1, anti-CASPR2, anti-AMPAR, and anti-GABA-B antibodies during the first psychotic episode to rule out autoimmune encephalitis (anti-NMDAR encephalitis = a treatable organic cause of psychosis)
- EEG if temporal epilepsy suspicion + or paroxysmal symptoms
- Brain MRI Systematic assessment in the first psychotic episode to rule out an organic cause (tumor, demyelination, focal atrophy, leukodystrophy)
- Basal metabolic assessment: Weight + BMI + waist circumference + fasting blood glucose + lipid profile + BP → before initiation of antipsychotics (reference for monitoring induced metabolic syndrome)
ℙ️
Anti-NMDA receptor encephalitisAnti-NMDAR encephalitis) is an organic and potentially curable cause of severe acute psychosis—particularly in young women—that can be mistaken for early-onset schizophrenia. The presentation combines psychosis + agitation + catatonia + epilepsy + dysautonomia + abnormal movements. Systematically testing for anti-NMDAR antibodies (blood + CSF) at the first psychotic episode prevents treating autoimmune encephalitis, which requires immunotherapy + and investigation for ovarian teratoma, with antipsychotics alone.
Pharmacological treatment
- Second-generation (atypical) antipsychotics — first-line: risperidone (2–8 mg/day) + olanzapine (10–20 mg/day) + quetiapine (300–750 mg/day) + aripiprazole (10–30 mg/day) + ziprasidone (120–160 mg/day) + paliperidone (6–12 mg/day) + lurasidone (40–160 mg/day) + asenapine → effective on positive symptoms + different side effect profile depending on the molecule + weight gain ++ (olanzapine) + metabolic syndrome + diabetes + dyslipidemia + prolactinemia (risperidone) + prolonged QTc (ziprasidone + quetiapine)
- 1st-generation antipsychotics (typical — 2nd line): haloperidol + fluphenazine + chlorpromazine → effective on positive symptoms but little effect on negative symptoms + high risk of extrapyramidal symptoms (EPS): parkinsonism + acute dystonia + akathisia + tardive dyskinesia → reserved for refractory forms + or for acute phase IV + or if cost is a constraint
- Clozapine (Clozaril®) — reserved for refractory schizophrenia: indicated after failure of 2 adequate antipsychotics (dose + duration) + most effective on positive AND negative symptoms + reduces suicidal risk (only antipsychotic with this indication) + dreaded side effects: agranulocytosis (0.5–1 % — mandatory weekly CBC monitoring × 18 weeks + monthly thereafter) + dose-dependent seizures + myocarditis + major weight gain + hypersalivation + sedation
- Long-acting antipsychotics (LAIs — depot injectables): Risperidone (Risperdal Consta® — 2 weeks) + Paliperidone (Invega Sustenna® monthly + Invega Trinza® quarterly) + Aripiprazole (Abilify Maintena® monthly + Aristada® 6 weeks) + Haloperidol decanoate + Fluphenazine decanoate → improve adherence + reduce relapses → to be preferred from the first episode if adherence is problematic
Non-pharmacological treatment and rehabilitation
- Psychoeducation for the patient and family + understanding of the illness + recognition of relapse signs + importance of adherence + reduction of family expressed emotion (EE) which increases the risk of relapse
- Cognitive Behavioral Therapy for Psychosis (CBTp): Reduces distress related to hallucinations and delusions + improves functioning + recommended as a complement to pharmacological treatment
- Cognitive remediation: Structured cognitive training programs (memory + attention + executive functions) → modest but significant improvement in cognitive performance and functioning
- Psychosocial Rehabilitation: Social skills retraining + Individual Placement and Support (IPS) employment support + supervised housing + community resources → improved social and vocational integration
- Early intervention for first episode: early psychosis intervention programs (EPIP — Early Psychosis Intervention Program in Quebec) → specialized teams + intensive follow-up + reduced time to treatment → significantly improves long-term prognosis
Psychiatric emergency
Call 911 or go immediately to the psychiatric emergency room if a person presents with a first episode of acute psychosis (hallucinations + delusions + disorganized behavior + significant agitation) OR if a person known to have schizophrenia experiences a severe relapse with agitation OR suicidal ideation OR behavior dangerous to themselves or others. Schizophrenia is associated with a suicide risk 10 to 20 times higher than the general population — suicidal ideation should always be assessed. For outpatient follow-up of stable schizophrenia and coordination with psychiatric teams, Clinique Omicron offers consultations at its service points in Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.
Consult at Clinique Omicron
Clinique Omicron's Nurse Practitioners (NPs) provide follow-up care for patients with stabilized schizophrenia in coordination with psychiatric teams. This includes monitoring antipsychotic treatment and its metabolic effects (blood glucose, lipids, weight, blood pressure), blood count monitoring for patients on clozapine, managing common medical comorbidities (smoking, diabetes, cardiovascular issues), referrals to psychiatric emergencies during relapses, and referrals to psychosocial rehabilitation programs available in Quebec. Consultations are available at several service points across Quebec and via telemedicine. To make an appointment, visit cliniqueomicron.ca.
The content of this page is for informational purposes only and does not replace the advice of a doctor or psychiatrist. Schizophrenia is a complex illness requiring specialized psychiatric care. Antipsychotics should never be stopped abruptly without medical advice — stopping suddenly significantly increases the risk of psychotic relapse. If thoughts of self-harm arise, consult a doctor or call 1-866-CALL (277-3553) — the Quebec provincial crisis line.
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