Skizofrenia

01Pathophysiology

Schizophrenia is a chronic, severe mental disorder characterized by impaired reality testing that disrupts thought content, thought process, perception, emotion, behavior, motivation, and cognition (including working memory, spatial/verbal memory, and executive function). The PNPK Skizofrenia 2025 defines it as a condition with persistent symptoms and frequent relapses that significantly reduce quality of life, ranking among the top 20 causes of disability worldwide.

The central pathophysiological model revolves around dopamine dysregulation. The mesolimbic pathway is hyperactive, producing excessive dopamine signaling that drives positive symptoms (hallucinations, delusions, disorganized speech and behavior). Conversely, the mesocortical pathway is hypoactive, meaning dopamine is deficient in the prefrontal cortex, which accounts for negative symptoms (flat affect, avolition, alogia, anhedonia, social withdrawal) and cognitive deficits (impaired attention, problem-solving, and executive function). This dual-pathway model is why antipsychotics that broadly block D2 receptors can improve positive symptoms while simultaneously worsening or failing to treat negative and cognitive symptoms.

Serotonin (5-HT2A) also plays a role. Second-generation antipsychotics provide combined D2 and 5-HT2A blockade, which partially restores dopamine transmission in the mesocortical pathway and accounts for their somewhat better profile for negative symptoms compared to first-generation agents.

The glutamate hypothesis (NMDA receptor hypofunction) provides an additional explanatory layer: reduced glutamatergic signaling leads to downstream dopamine dysregulation, particularly in prefrontal circuits. This is supported by the observation that NMDA antagonists like phencyclidine (PCP) and ketamine can reproduce both positive and negative symptoms in healthy individuals.

The disease follows a staged clinical trajectory as outlined in the PNPK Skizofrenia 2025 (adapted from RANZCP). It begins with a prodromal/pre-psychotic phase (Stages 1a-1b) marked by subtle cognitive decline and subthreshold psychotic symptoms, progresses to a first psychotic episode (Stage 2) where full diagnostic criteria are met, and may advance to persistent/recurrent illness (Stages 3a-3c) and eventually chronic, treatment-refractory disease (Stage 4). The concept of Duration of Untreated Psychosis (DUP) is critical: the PNPK states that the average DUP in Indonesia is 84 weeks (21 months), and a DUP exceeding 6 months predicts worse negative symptoms, poorer cognitive and social outcomes, and reduced treatment response. The WHO recommends initiating treatment within 3 months of symptom onset.

The prevalence is approximately 0.5 to 1% across populations worldwide. Indonesia estimates about 2.6 million people with schizophrenia, with a household prevalence of 3 per 1,000 (SKI 2023). Affected individuals have a standardized mortality ratio 2 to 4 times that of the general population and die 10 to 25 years earlier, largely from cardiovascular disease, metabolic syndrome, and suicide.

02Classification and Clinical Manifestation

DSM-5 vs. ICD-10

Symptom Domains

Clinical Staging

Disease Course Specifiers

03Diagnostic Workup

The PNPK Skizofrenia 2025 emphasizes that there is no single test that definitively confirms schizophrenia. Diagnosis is entirely clinical, established through comprehensive psychiatric evaluation including history-taking, mental status examination, and collateral information from family or close contacts. This is the best initial step in every vignette.

The most common exam trap is a question that tempts you to order imaging or labs to "confirm" schizophrenia. Brain imaging and labs are ordered to rule out organic and substance-induced psychosis, not to make the diagnosis. The PNPK recommends MRI (preferred over CT) for first-episode psychosis to exclude structural pathology, and laboratory panels (CBC, metabolic, thyroid, toxicology) to screen for medical mimics.

Quantitative scales like the PANSS (Positive and Negative Syndrome Scale) are used for documenting severity and tracking treatment response. The PNPK highlights the PANSS-6 (a 6-item version covering delusions, conceptual disorganization, hallucinations, blunted affect, social withdrawal, and lack of spontaneity) as highly correlated with the full 30-item scale and sensitive to change with treatment. PANSS-remission criteria (items P1, P2, P3, N1, N4, N6, G5, G9 all scoring 3 or below) are used for referral back and defining clinical stability.

A structured diagnostic interview such as the MINI (Mini International Neuropsychiatric Interview) or SCID (Structured Clinical Interview for DSM) may be used, particularly in research contexts, to systematically confirm the diagnosis.

04Management and Treatment

First-Line Antipsychotic Dosing

Step 1: Start an SGA at a low dose and titrate gradually. The PNPK recommends SGAs over first-generation antipsychotics (FGAs) for the first psychotic episode due to better tolerability and lower extrapyramidal side effect (EPS) risk. Young patients and first-episode patients respond at lower doses and are more sensitive to side effects, so the principle is "start low, go slow" except in psychiatric emergencies.

Step 2: Assess response at 2 to 3 weeks. If response is inadequate, increase the dose and optimize psychosocial interventions. Evidence shows that a patient who does not achieve at least a 20% symptom reduction within 2 weeks at a therapeutic dose is unlikely to achieve a 50% reduction in the next 4 to 6 weeks. This is the signal to adjust management.

Step 3: If no response by 6 to 8 weeks, cross-taper to a different SGA. The PNPK algorithm advises cross-over switching to another SGA.

Step 4: If the second antipsychotic trial also fails, review causes of failure (nonadherence, substance use, psychosocial stressors). Consider olanzapine if not yet tried.

Step 5: If two adequate trials fail, switch to clozapine. Clozapine is the only antipsychotic proven superior to other antipsychotics in treatment-resistant schizophrenia. The PNPK is clear: clozapine initiation requires slow titration (starting 12.5 mg once or twice daily, increasing by 25 to 50 mg/day to a target of 300 to 450 mg/day, with larger increases of up to 100 mg per week if needed). Rapid dose escalation risks cardiovascular collapse, seizures, orthostatic hypotension, and excessive sedation, especially when co-administered with benzodiazepines.

Clozapine safety monitoring: The most feared adverse effect is severe neutropenia (ANC <500/uL). Risk is highest in the first 6 months. The PNPK mandates baseline and ongoing ANC monitoring. If clozapine is interrupted for 30 days or more, the patient must restart from the initial titration protocol and monitoring schedule.

Step 6: For treatment-resistant patients with inadequate clozapine response, consider ECT augmentation. The PNPK recommends ECT combined with antipsychotics when rapid clinical response is a priority. ECT index treatment combined with clozapine may be beneficial. If ECT index is effective, consider continuation ECT for at least 6 months (weekly for 1 month, then biweekly). ECT electrode placement may be right unilateral, bifrontal, or bitemporal. Generally, unilateral is given at 3 to 6 times the seizure threshold, while bitemporal/bifrontal is given at 1.5 times the threshold.

Adjunctive benzodiazepines are used short-term in the acute phase: diazepam for agitation/aggression, lorazepam for anxiety, temazepam for sleep disturbance.

Maintenance treatment: The PNPK states that after resolution of positive symptoms from an acute episode, patients should receive maintenance antipsychotic therapy for 2 and possibly up to 5 years or more. In a 5-year follow-up of first-episode patients, 81.9% relapsed when treatment was discontinued. If discontinuation is attempted, taper the medication over a minimum of 3 to 6 months with close monitoring.

Long-Acting Injectables (LAI) may be offered as first-line treatment within a shared decision-making framework, and are especially useful for patients with poor adherence. The PNPK notes that LAI can be given as a primary treatment strategy, not just as a last resort for nonadherence.

Non-pharmacological interventions are integral components of care across all phases:

Cognitive Behavioral Therapy for Psychosis (CBTp): minimum 16 sessions recommended. Helps patients develop alternative explanations for maladaptive cognitive assumptions.

Psychoeducation: both patient and family education about diagnosis, treatment, relapse prevention, and crisis planning. A 12-session program is the typical standard.

Family interventions: reduce relapse and rehospitalization rates.

Supported employment and education services: focus on competitive employment placement with ongoing support.

05Differential Diagnosis and Distractors

06Traps and High-Yield Pearls

The single most common way students lose points on schizophrenia questions is by ordering a lab or imaging study to "confirm" the diagnosis when the vignette has already provided a clear clinical picture. There is no confirmatory test. Brain MRI, CBC, TSH, and urine drug screen are ordered to exclude other etiologies, never to confirm schizophrenia. When the vignette describes a young adult with 6+ months of auditory hallucinations, paranoid delusions, flat affect, and functional decline with a negative toxicology and normal labs, the answer is schizophrenia and the next best step is starting an antipsychotic, not ordering further tests.

The second major trap involves the duration criterion. DSM-5 requires a total illness duration of at least 6 months (which can include prodromal or residual symptoms), with at least 1 month of active-phase symptoms. ICD-10 only requires 1 month of active symptoms. If the vignette specifies a 3-month total duration with full psychotic features, the DSM-5 answer is schizophreniform disorder, not schizophrenia. If the symptoms last less than 1 month, it is brief psychotic disorder. This time-based hierarchy is a favorite testing target.

The third classic trap is the treatment-resistant schizophrenia question. After two adequate antipsychotic trials have failed, the next best step is clozapine, never a third conventional antipsychotic and never polypharmacy with two non-clozapine agents. The PNPK Skizofrenia 2025 is unequivocal: clozapine is the only antipsychotic with proven superiority for treatment-resistant disease. The required monitoring (ANC for agranulocytosis risk) is also high-yield.

Another frequently tested pearl is the distinction between primary and secondary negative symptoms. A vignette describing a patient with flat affect, social withdrawal, and amotivation who is on a high-potency FGA (like haloperidol) is testing whether you recognize drug-induced parkinsonism (secondary negative symptoms) and know to switch to an SGA or reduce the dose, rather than diagnosing worsening illness.

Finally, know the comorbidities: 50% comorbid depression, 47% substance use disorders, 29% PTSD, 23% OCD, and 15% panic disorder (PNPK Skizofrenia 2025). A vignette describing a patient with schizophrenia and new-onset depressive symptoms is testing whether you address the mood disorder (consider antidepressant augmentation or psychotherapy) rather than simply increasing the antipsychotic dose.

The core competency being tested across all schizophrenia questions is your ability to recognize the disease through its symptom domains, sequence the diagnostic exclusion of organic causes correctly, select first-line pharmacotherapy with an awareness of side-effect profiles, and identify the clear threshold for clozapine initiation.