1. Criteria

Two or more characteristic symptoms are present for a significant part of 1 month, or less if successfully treated.
At least one symptom is delusions, hallucinations, or disorganized speech.
The characteristic symptoms are delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms such as diminished emotional expression or avolition.

For a significant portion of the time since onset, level of functioning in work, interpersonal relations, or self-care is markedly below the prior level.

Continuous signs of disturbance persist for at least 6 months.

Schizoaffective disorder and mood disorders with psychotic features have been ruled out appropriately.

The disturbance is not attributable to a substance or another medical condition.

Functioning in work, interpersonal relations, or self-care is markedly below prior level.
If there is a history of autism spectrum disorder or communication disorder of childhood onset, prominent delusions or hallucinations must also be present for at least 1 month.

2. Context

Schizophrenia is a chronic psychotic illness in which delusions, hallucinations, disorganization, and negative symptoms begin to reshape how a person functions over time. The diagnosis becomes clearer when the psychotic symptoms persist, functioning drops, and shorter or mood-driven explanations stop fitting well.
Timeline: The timing matters. You need at least 1 month of active symptoms within a broader disturbance that lasts 6 months or longer.
Mandatory symptom mix: Not every symptom combination qualifies. You need at least two core psychotic symptoms, and one of them must be delusions, hallucinations, or disorganized speech.
Functional anchor: A real drop in work, relationships, school performance, or self-care helps separate schizophrenia from briefer or less entrenched psychotic syndromes.
Clinical focus: Broad clinician-rated severity measure across positive, negative, and general psychopathology.

3. Validated scales

PANSS

Broad clinician-rated severity measure across positive, negative, and general psychopathology.

BPRS

Shorter psychosis severity instrument for inpatient or consultation settings.

CGI-S

Fast global severity check when full psychosis scales are not practical.

AIMS

Essential when monitoring tardive dyskinesia during antipsychotic treatment.

4. FDA approved treatments

Treatment of schizophrenia

FDA-approved antipsychotics for schizophrenia vary by age bracket and formulation; verify product-specific labeling.

Treatment-resistant schizophrenia and suicidality

Clozapine carries distinct FDA labeling for treatment-resistant schizophrenia and for reducing recurrent suicidal behavior in schizophrenia or schizoaffective disorder.

Long-acting injectable options

These are useful when adherence is a major driver of relapse risk; check each product for oral overlap and maintenance requirements.

Common off-label medications

Interventional psychiatry modalities

ECT is used in catatonia, severe psychosis, or clozapine-resistant cases.
TMS is under investigation for hallucinations and negative symptoms.
Ketamine is not a standard schizophrenia treatment and is mainly research-limited here.

5. Top management articles

Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia The Lancet, 2013
Clozapine for the treatment-resistant schizophrenic Archives of General Psychiatry, 1988
The American Psychiatric Association practice guideline for the treatment of patients with schizophrenia APA guideline

Simple Psych

Schizophrenia