TextbookPsychiatry & Mental HealthFirst Episode Psychosis

First Episode Psychosis

First episode psychosis represents the initial presentation of psychotic symptoms. Early intervention within 2 weeks via EIP services significantly improves long-term outcomes.

Key Facts

Duration of untreated psychosis (DUP) is the strongest modifiable prognostic factor — shorter DUP = better outcomes NICE mandates referral to EIP services within 2 weeks; EIP provides care for 3 years, ages 14-65 Prodromal symptoms may precede FEP by 1-5 years: social withdrawal, declining function, unusual ideas First-line: Low-dose oral atypical antipsychotic + CBTp + family intervention Cannabis is the most important modifiable risk factor — high-potency use in adolescence doubles risk Up to 25% may have underlying organic cause — thorough investigation is mandatory Incidence ~32 per 100,000/year; peak age 18-24; Black Caribbean populations have 5-10× higher rates in UK 75% of psychotic disorders begin before age 25

Overview

Key Facts

FEP is a critical period where early comprehensive intervention has the greatest impact on long-term outcomes. NHS mandates access to EIP services for all cases.

Epidemiology

Incidence approximately 32 per 100,000/year in the UK. Peak onset 18-24 years. Males have earlier onset. Significant health inequalities — Black Caribbean and Black African populations have 5-10× higher rates.

Aetiology

Genetic predisposition + neurodevelopmental factors + environmental stressors (cannabis, social adversity, urban environment) → dopaminergic dysregulation → psychosis (stress-vulnerability model).

Pathophysiology

  • Prodromal phase (1-5 years before FEP): Progressive neurobiological change before threshold symptoms
  • Critical period hypothesis: First 2-5 years after FEP are a window of neuroplasticity where intervention has maximal impact
  • Mesolimbic dopamine overactivity drives positive symptoms
  • Excessive synaptic pruning in adolescence may contribute (C4 gene association)

Clinical Presentation

Prodromal Features

  • Declining academic/occupational performance
  • Social withdrawal, suspiciousness, irritability
  • Unusual/magical thinking, sub-threshold psychotic experiences
  • Sleep disturbance, reduced motivation

Psychotic Episode

  • Positive symptoms: Delusions, hallucinations, thought disorder
  • Behavioural change: Bizarre behaviour, agitation, self-neglect
  • Cognitive decline, negative symptoms may be present from outset

Red Flags

  • Organic features (confusion, visual hallucinations, seizures, focal neurology) — investigate urgently
  • Catatonia (immobility, mutism, posturing) — medical emergency
  • High suicide risk: ~5% die by suicide within first 5 years
  • Command hallucinations to harm self/others

Differential Diagnosis

DiagnosisKey FeaturesInvestigation
Substance-induced psychosisTemporal relationship to drug use, resolves with abstinenceUrine drug screen
Bipolar maniaElevated mood, episodic courseMood assessment, collateral
Autoimmune encephalitisYoung woman, movement disorder, seizures, psychiatric symptomsNMDA receptor antibodies, MRI, EEG
DeliriumFluctuating consciousness, acute onset, medical causeSeptic screen, bloods
Temporal lobe epilepsyBrief episodes, automatisms, déjà vuEEG
Psychotic depressionMood-congruent delusions during severe depressionPHQ-9

Diagnosis / Investigation

Bedside

  • Full MSE and neurological examination
  • Risk assessment: Suicide, violence, self-neglect, vulnerability
  • Collateral history: Essential

Bloods

  • FBC, U&Es, LFTs, TFTs, fasting glucose, HbA1c, lipids: Baseline and organic screen
  • Calcium, B12, folate, CRP: Metabolic/inflammatory causes
  • HIV, syphilis serology: Infective causes
  • Urine drug screen: Cannabis, amphetamines, cocaine
  • NMDA receptor antibodies: If encephalitis suspected

Imaging

  • MRI brain: Recommended in all FEP to exclude organic pathology

Special Tests

  • ECG: Baseline before antipsychotic
  • EEG: If seizures suspected
  • Neuropsychological assessment: Baseline cognitive profile

Management

Non-pharmacological

  • EIP team: Comprehensive care package for 3 years
  • CBTp: ≥16 sessions
  • Family intervention: ≥10 sessions — reduces relapse by ~50%
  • Supported employment/education: IPS model
  • Physical health monitoring: Annual metabolic screening

Pharmacological

  • Low-dose atypical antipsychotic: Aripiprazole 5-15mg, risperidone 1-4mg, or olanzapine 5-15mg
  • Start lowest dose, titrate slowly; trial 4-6 weeks before switching
  • Continue ≥1-2 years after FEP
  • Clozapine if failed 2 adequate trials

Referral Criteria

  • All suspected FEP — EIP team within 2 weeks (NHS standard)
  • Organic features — neurology
  • Under 14 — CAMHS
  • Postpartum psychosis — perinatal team

Prognosis

  • ~25% single episode with full recovery
  • ~50% relapsing-remitting course
  • ~25% chronic, treatment-resistant illness
  • DUP >3 months associated with significantly worse outcomes
  • Suicide: ~5% in first 5 years
  • EIP services reduce hospitalisation by 50% and improve employment
  • Cannabis cessation after FEP significantly improves outcomes

Other Relevant Information

EIP Core Components (NICE CG178)

ComponentDetails
Antipsychotic medicationLow-dose atypical, shared decision-making
CBTp≥16 sessions
Family intervention≥10 sessions
Supported employmentIPS model
Physical healthMetabolic monitoring
Substance misuse supportIntegrated approach
Carer supportAssessment and support