[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Conditions](https://durgical.com/en/conditions/) › Schizophrenia [Conditions](https://durgical.com/en/conditions/) · [Psychiatry](https://durgical.com/en/conditions/) # Schizophrenia Schizophrenia is a serious mental illness with psychosis, such as hallucinations and delusions, and loss of drive. Early treatment helps recovery. Updated 2026-11-01 ## Structures involved Tap one to see what it is and open it in 3D. - [Frontal lobe](https://durgical.com/en/anatomy/superior-frontal-gyrus/) - [Temporal lobe](https://durgical.com/en/anatomy/middle-temporal-gyrus/) - [Hippocampus](https://durgical.com/en/anatomy/hippocampus/) - [Caudate nucleus](https://durgical.com/en/anatomy/caudate-nucleus/) - [Midbrain](https://durgical.com/en/anatomy/midbrain/) - [Substantia nigra](https://durgical.com/en/anatomy/substantia-nigra/) - [Putamen](https://durgical.com/en/anatomy/putamen/) - [Thalamus](https://durgical.com/en/anatomy/thalamus/) - [Pituitary gland](https://durgical.com/en/anatomy/pituitary-gland/) ## Why it happens - [Multifactorial (complex) disorders](https://durgical.com/en/general-pathology/multifactorial-disorders/) - [Trisomies 21, 18 and 13, and the 22q11.2 deletion](https://durgical.com/en/general-pathology/trisomies-21-18-and-13-and-the-22q11-2-deletion/) - [The main neurotransmitters](https://durgical.com/en/physiology/the-main-neurotransmitters/) - [Dopamine](https://durgical.com/en/biochemistry/molecules/dopamine/) ## What it is A chronic psychotic disorder with positive symptoms (delusions, hallucinations, disorganised speech and behaviour), negative symptoms and cognitive impairment, lasting at least six months with at least one month of active symptoms and a decline in functioning. ## Who gets it Affects about 1 in 300 people worldwide. It usually begins in late adolescence or early adulthood, slightly earlier in men. Many people with psychosis in low- and middle-income countries, including Latin America, do not receive specialist care, and stigma is common. ## Causes - Strong genetic component with many genes of small effect - Neurodevelopmental factors: obstetric complications, prenatal infection or malnutrition - Environmental factors that interact with genetic risk ## Risk factors - First-degree relative with schizophrenia - Heavy cannabis use in adolescence - Advanced paternal age - Obstetric complications and prenatal infection - Urban upbringing, migration, childhood trauma and social adversity ## Pathophysiology The dopamine hypothesis: excess dopamine in the mesolimbic pathway produces positive symptoms, while low dopamine in the mesocortical pathway to the prefrontal cortex is linked to negative and cognitive symptoms. Blocking D2 receptors in the nigrostriatal pathway ([substantia nigra](https://durgical.com/en/anatomy/substantia-nigra/) to caudate and [putamen](https://durgical.com/en/anatomy/putamen/)) causes extrapyramidal effects, and in the tuberoinfundibular pathway raises prolactin. Glutamate (NMDA) hypofunction also contributes; imaging shows enlarged ventricles and reduced cortical and hippocampal volume. ## Classification - Brief psychotic disorder: less than one month - Schizophreniform disorder: one to six months - Schizophrenia: six months or more - Schizoaffective disorder: psychosis plus major mood episodes, with psychosis also present without mood symptoms ## Symptoms and signs - Delusions (persecutory, of reference, of control) - Hallucinations, most often auditory voices - Disorganised speech (loosening of associations) and behaviour - Negative symptoms: flat affect, alogia, avolition, anhedonia and social withdrawal - Cognitive impairment: attention, memory and executive function - Poor insight into the illness ## Red flags - Suicidal thoughts or command hallucinations to harm self or others - Severe agitation or aggression - Catatonia - Fever, rigidity, confusion and autonomic instability on antipsychotics (neuroleptic malignant syndrome) - Fever, sore throat or infection on clozapine (possible agranulocytosis) ## Diagnosis **Clinical** Clinical diagnosis by DSM-5 or ICD-11 criteria: two or more core symptoms (at least one of delusions, hallucinations or disorganised speech) with continuous signs for six months and functional decline, after excluding mood disorders, substances and medical causes. **Tests** To rule out other causes: blood count, glucose, electrolytes, [kidney](https://durgical.com/en/anatomy/kidney/), [liver](https://durgical.com/en/anatomy/liver/) and thyroid function, drug screening, HIV and syphilis serology. Baseline weight, waist, glucose and lipids, and an ECG before antipsychotics when indicated. **Imaging** MRI or CT in a first episode with atypical features or neurological signs to exclude tumours, encephalitis or other lesions; may show enlarged ventricles. ## Differential diagnosis - Substance-induced psychosis (cannabis, stimulants, alcohol withdrawal) - Bipolar disorder or depression with psychotic features - Schizoaffective, schizophreniform and delusional disorders - Delirium and dementia - Medical causes: [temporal lobe](https://durgical.com/en/anatomy/middle-temporal-gyrus/) epilepsy, autoimmune encephalitis, brain tumour, neurosyphilis ## Goal of treatment Control psychotic symptoms, prevent relapse, support recovery of functioning and social inclusion, and protect physical health. ## Treatment **Medical** Antipsychotics, first- and second-generation, are the core of treatment; long-acting injectable forms help when adherence is poor. Clozapine is reserved for treatment-resistant schizophrenia (after two adequate trials) and reduces suicidal behaviour. **Acute** Acute agitation: calm de-escalation first, then antipsychotics with or without benzodiazepines; hospital admission when there is risk to self or others. **Conservative** Psychosocial care: family psychoeducation, cognitive behavioural therapy for psychosis, social skills training, supported employment and community mental health care. **Follow-up** Monitoring of adverse effects: extrapyramidal symptoms, tardive dyskinesia, hyperprolactinaemia, weight, glucose and lipids (metabolic syndrome), QT prolongation; regular neutrophil counts on clozapine. Nursing: adherence, safety and physical health. ## Drugs for this condition - [Prochlorperazine](https://durgical.com/en/pharmacology/prochlorperazine/) ## Complications - Suicide - Cardiovascular disease and metabolic syndrome, shortening life expectancy - Substance use and tobacco dependence - Homelessness, unemployment and social exclusion - Treatment effects: tardive dyskinesia, neuroleptic malignant syndrome, agranulocytosis with clozapine ## Prognosis Variable: a significant share recover well and many improve, while others have a relapsing or chronic course. Good prognosis factors include acute onset, later onset, clear triggers, prominent positive symptoms, good premorbid functioning and early treatment. ## Prevention - Early intervention services for a first episode of psychosis - Reducing cannabis use in adolescents - Maintenance treatment and family support to prevent relapse ## Test yourself Think of the answer, then tap the question to see it. ## Which dopamine pathway is linked to the positive symptoms of schizophrenia? The mesolimbic pathway, with excess dopamine activity. ## How long must symptoms last for a diagnosis of schizophrenia? At least six months, including at least one month of active symptoms. ## When is clozapine indicated, and what must be monitored? Treatment-resistant schizophrenia (and suicidal behaviour); neutrophil counts because of agranulocytosis risk. ## What are three negative symptoms of schizophrenia? Flat affect, alogia (poverty of speech) and avolition; also anhedonia and social withdrawal. ## Which pathway blockade causes raised prolactin? D2 blockade in the tuberoinfundibular pathway. [Add to my cards (5)](https://durgical.app/estudiar/?add=/en/conditions/schizophrenia/) ## Related conditions - [Bipolar disorder](https://durgical.com/en/conditions/bipolar-disorder/) - [Major depressive disorder](https://durgical.com/en/conditions/major-depressive-disorder/) - [Suicidal behaviour and suicide risk](https://durgical.com/en/conditions/suicidal-behaviour-and-suicide-risk/) - [Alcohol use disorder](https://durgical.com/en/conditions/alcohol-use-disorder/) - [Metabolic syndrome](https://durgical.com/en/conditions/metabolic-syndrome/) - [Obesity](https://durgical.com/en/conditions/obesity/) - [Parkinson disease](https://durgical.com/en/conditions/parkinson-disease/) Educational information, not medical advice. For any symptom, see a health professional. Sources: [Schizophrenia](https://www.who.int/news-room/fact-sheets/detail/schizophrenia) (World Health Organization, 2025); [Schizophrenia](https://medlineplus.gov/schizophrenia.html) (MedlinePlus (National Library of Medicine), 2025). [← All conditions](https://durgical.com/en/conditions/) ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/conditions/schizophrenia/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/conditions/schizophrenia/