Schizophrenia is a mental disorder characterized by the presence of positive symptoms (delusions, hallucinations), disorganization, and negative symptoms (poverty of thought, amotivation).
Risk Factor (affected) | Average Relative Risk (%) |
---|---|
Monozygotic twin | 50-70% |
Both parents | 40-60% |
Dizygotic twin or 1st degree relative | 9-18% |
2nd degree relative (e.g. - grandparent) | 3-6% |
3rd degree relative (e.g. - 1st cousin) | 2-3% |
Urbanicity | 2-3% |
Migration | 2-3% |
1st or 2nd trimester maternal infection | 2-3% |
Winter birth | 1.1% |
Obstetric and Perinatal Complications | 2-3% |
Paternal Age >35 | 1.5-3% |
Male Gender | 1.4% |
At least 2
of the following, each present for a significant portion of time during a 1
-month period (or less if successfully treated). At least 1
of these must be (1), (2), or (3):
For a significant portion of the time since the onset of the disturbance, level of functioning in at least 1
major area, such as work, interpersonal relations, or self-care, is markedly below the level achieved prior to the onset (or when the onset is in childhood or adolescence, there is failure to achieve expected level of interpersonal, academic, or occupational functioning).
Continuous signs of the disturbance persist for at least 6
months. This 6
-month period must include at least 1
month of symptoms (or less if successfully treated) that meet Criterion A
(i.e. - active-phase symptoms) and may include periods of prodromal or residual symptoms. During these prodromal or residual periods, the signs of the disturbance may be manifested by only negative symptoms or by 2
or more symptoms listed in Criterion A
present in an attenuated form (e.g. - odd beliefs, unusual perceptual experiences).
Schizoaffective disorder and depressive or bipolar disorder with psychotic features have been ruled out because either:
The disturbance is not attributable to the physiological effects of a substance (e.g. - a drug of abuse, a medication) or another medical condition.
If there is a history of autism spectrum disorder or a communication disorder of childhood onset, the additional diagnosis of schizophrenia is made only if prominent delusions or hallucinations, in addition to the other required symptoms of schizophrenia, are also present for at least 1
month (or less if successfully treated).
Specify if:
Specify if:
Specify current severity:
7
days) on a 5-point scale ranging from 0 (not present) to 4 (present and severe).Name | Rater | Description | Download |
---|---|---|---|
Positive and Negative Syndrome Scale (PANSS) | Clinician | The patient is rated from 1 to 7 on 30 different symptoms based on the interview as well as reports of family members or primary care hospital workers. It is a 45-minute clinical interview. | Link |
Brief Psychiatric Rating Scale (BPRS) | Clinician | The BPRS is has 24 symptom constructs, each rated on a 7-point scale of severity ranging from “not present” to “extremely severe.” | Download |
Calgary Depression Scale for Schizophrenia (CDSS) | Clinician | The CDSS is a 9 item scale that measures the level of depression in individuals with schizophrenia. | Link |
A wide variety of mental disorders and medical conditions can manifest with psychotic symptoms, and must be considered in the differential diagnosis of a schizophreniform disorder or schizophrenia diagnosis, or any diagnosis of a primary psychotic disorder.[52]
The term psychosis has been defined in various ways in the medical literature over time. The narrowest and current definition of psychosis is hallucinations and delusions, with the lack of reality testing or insight. A broader definition of psychosis would also include disorganized thought, emotions, and behaviour. This loose definition was more common in the past, and schizophrenia was often overdiagnosed as a result.
Type | Onset | Length | Psychotic Symptoms | Mood Symptoms | Functional Decline? |
---|---|---|---|---|---|
Brief psychotic disorder | Sudden | 1 day to 1 month | At least 1 of: • Delusions • Hallucinations • Disorganized speech • Grossly disorganized or catatonic behaviour | No | Full resolution of symptoms |
Schizophreniform disorder | Can be prodromal | 1 month to 6 months | At least 2 of: • Delusions • Hallucinations • Disorganized speech • Grossly disorganized or catatonic behaviour • Negative symptoms | No | Not required |
Schizophrenia | Can be prodromal | > 6 months | At least 2 of: • Delusions • Hallucinations • Disorganized speech • Grossly disorganized or catatonic behaviour • Negative symptoms | No | Required |
Schizoaffective disorder | Can be prodromal | Major mood episode + 2 weeks of isolated psychotic symptoms + predominantly mood symptoms over course of illness | • Delusions or hallucinations for 2 or more weeks, which must be in absence of a major mood episode (depressive or manic) during the lifetime duration of the illness | Required | Not required |
Delusional disorder | Can be prodromal | > 1 month | • One or more delusions, with no other psychotic symptoms. | No | Normal function aside from impact of delusions |
All patients who are on long-term antipsychotics must be medically monitored routinely.
Initiation | 1 month after initiation | 3 months after initiation | Then annually | |
---|---|---|---|---|
Electrolytes, Cr, LFTs, TSH | ✓ | As clinically indicated | As clinically indicated | As clinically indicated |
Fasting plasma glucose | ✓ | As clinically indicated | ✓ | ✓ |
HbA1c | ✓ | - | ✓ | ✓ |
Lipid panel (total cholesterol, LDL, HDL, triglycerides) | ✓ | As clinically indicated | ✓ | ✓ |
Body mass (BMI) | ✓ | ✓ | ✓ | ✓ |
Blood pressure (BP) | ✓ | As clinically indicated | ✓ | ✓ |
Extrapyramidal symptom (EPS) exam | ✓ | ✓ | ✓ | ✓ |
Endocrine function history (gynecomastia, galactorrhea, libido) | ✓ | - | ✓ | ✓ |
Prolactin | If clinically indicated | If clinically indicated | If clinically indicated | If clinically indicated |
ECG (QT monitoring) | If clinically indicated (some clinicians will order this routinely as a baseline) | - | If on multiple QTc-prolonging medications (or if clinically indicated) | As clinically indicated, or yearly |
Smoking history | ✓ | - | ✓ | ✓ |
Guideline | Location | Year | Website | |
---|---|---|---|---|
Canadian Schizophrenia Guidelines | Canada | 2017 | - | Link |
National Institute for Health and Care Excellence (NICE) | UK | 2014 | - | Link |
Scottish Intercollegiate Guidelines Network (SIGN) | UK | 2013 | - | Link |
American Psychiatric Association (APA) | USA | 2021 | - | Link |
Royal Australian and New Zealand College of Psychiatrists (RANZCP) | AUS, NZ | 2016 | - | Link |