Schizophrenia

Entitlement Eligibility Guideline (EEG)

Date reviewed: 22 January 2025

Date created: May 2011

ICD-11 code: 6A20

VAC medical code: 00607 Schizophrenia

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Definition

Schizophrenia is a condition in the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition - Text Revision (DSM-5-TR) category of schizophrenia spectrum and other psychotic disorders. The common features of schizophrenia may include delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behaviour, and negative symptoms.

The following is a list of terms contained in Criterion A of the criteria set for schizophrenia:

Delusion is a false fixed belief. The content may include a variety of themes:

  • persecutory, for example, belief one is being followed
  • referential, for example, a passage from a book is specifically directed at oneself
  • religious, for example, belief one is an important religious figure.

Non-bizarre delusions are derived from plausible life experiences, for example the belief one is under surveillance by the police. Bizarre delusions are clearly implausible, for example the belief one’s internal organs are removed and replaced with someone else’s organs.

A belief is not considered to a delusion if it is reasonable given the context, for example a belief one will be assaulted in a threatening environment.

Hallucination is a sensory experience that has no basis in external stimulation. In schizophrenia, auditory hallucinations are the most common. An example would be hearing a voice maintaining a running commentary on the person's behaviour or thoughts.

Disorganized speech infers the presence of disorganized thinking. Elements may include, for example:

  • derailment or loose associations (disorderly switching from one topic to another)
  • tangentiality (answers to questions may be loosely related or completely unrelated)
  • incoherent speech, severe enough to impair communication (word salad).

Grossly disorganized behaviour may be manifested in a variety of ways, for example dressing in an unusual manner, unpredictable and untriggered agitation or catatonic behaviour. Catatonic behaviours can be a complete lack of verbal and motor responses (mutism and stupor), maintenance of a rigid, inappropriate or bizarre posture or purposeless or excessive motor activity without obvious cause (catatonic excitement).

Negative symptoms are a reduction or loss of normal functions which account for a substantial portion of the morbidity associated with schizophrenia.

The two negative symptoms which are prominent in schizophrenia are:

  • diminished emotional expression
  • avolition.

Diminished emotional expression is a reduction in nonverbal communication such as facial expression, eye contact, or gestures of the head or hands.

Avolition is a decrease in motivation for self-initiated and purposeful activities, for example showing little interest in work or social activities.

Other negative symptoms include:

  • alogia – diminished speech output
  • anhedonia – decreased ability to experience pleasure from current or past experiences
  • asociality – lack of interest in social interactions.

Diagnostic standard

A diagnosis from a qualified medical practitioner (family physician or psychiatrist), nurse practitioner, or a registered/licensed psychologist is required.

The diagnosis is made clinically. Supporting documentation should be as comprehensive as possible.

Clinical features

Schizophrenia is a complex condition which reflects an interaction between genetic vulnerability and environmental contributors. None of the considerations for schizophrenia alone is sufficient for the development of schizophrenia, and they operate at various levels to contribute to the onset and progression of schizophrenia. Research and understanding of schizophrenia continues to evolve.

Biological considerations: Schizophrenia has a well-established genetic component. Genome-wide analyses of schizophrenia have identified more than 100 genetic contributors. Genes alone are not sufficient to account for schizophrenia and some of the risk may be due to gene-environment interactions. Studies in twins who share 100% of their genes show a concordance rate of 40-50%, suggesting both genetic and environmental factors contribute to the development of schizophrenia.

Advances in neuroscience have identified neurochemical disturbances and brain functional changes in different regions of the brain for individuals living with schizophrenia. Neuroanatomical changes have been shown in the early stages of psychosis that are different than those associated with normal development. Several neurotransmitters are also involved in the pathology of schizophrenia, including dopamine, glutamate, gamma-aminobutyric acid, and acetylcholine.

Environmental considerations: Environmental risk factors for schizophrenia include pregnancy and birth complications, childhood trauma, migration, social isolation, urban living, and substance abuse. These factors may act alone or in combination towards the development of schizophrenia. Advanced paternal age has been associated with schizophrenia, suggesting that age-associated mutations in male germ cells may play a role. The impact of maternal age is unclear from present research with mixed findings.

Trauma and social differences have been extensively investigated as potential risk factors for schizophrenia. Social inequalities are associated with psychosis. First-episode psychosis patients are more likely to live alone, be single or unemployed, live in rented accommodation, live in overcrowded conditions, and receive an income below the poverty line. These conditions are found at first contact with psychiatric services but exist up to five years prior to the onset of psychosis.

Growing up in an urban environment has frequently been associated with an increased risk of schizophrenia or psychosis in general. The more years a child spends in an urban area, the greater the risk becomes. Conversely, research shows living in or near a greenspace (appreciable to the size of the greenspace) during childhood lessens the risk of later developing schizophrenia.

Substance use is highly prevalent in psychotic individuals. There is good evidence that a number of substances can induce psychosis. Cannabis has been consistently reported to be associated with schizophrenia, with a dose-response relationship between extent of use and risk of psychosis.

Slightly more males than females are diagnosed with schizophrenia. Females tend to be diagnosed later in life than males, with a second spike of diagnoses later in life. Females tend to experience more mood-related symptoms that may increase in severity over the course of their lives. Psychotic symptoms have been observed to worsen during the premenstrual time period when estrogen levels are dropping, improve during pregnancy when estrogen levels are high, and worsen again postpartum when estrogen levels quickly drop. There is evidence the prognosis may be worse in males as they experience negative symptoms, disorganized thinking, and social impairment more frequently.

Criteria set

The schizophrenia criteria set is derived from the DSM-5-TR.

This EEG provides the DSM-5-TR diagnostic criteria; however, the International Classification of Diseases 11th Revision (ICD-11) is also considered an acceptable diagnostic standard.

Criterion A

Two (or more) of the following, each present for a significant portion of time during a one-month period (or less if successfully treated). At least one of these must be (1), (2) or (3):

  1. delusions
  2. hallucinations
  3. disorganized speech (e,g., frequent derailment or incoherence)
  4. grossly disorganized or catatonic behaviour
  5. negative symptoms (i.e., diminished emotional expression or avolition).

Criterion B

For a significant portion of the time since the onset of the disturbance, level of functioning in one or more major areas, 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).

Criterion C

Continuous signs of the disturbance persist for at least six months. This six-month period must include at least one 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 two or more symptoms listed in Criterion A present in an attenuated form (e.g., odd beliefs, unusual perceptual experiences).

Criterion D

Schizoaffective disorder and depressive or bipolar disorder with psychotic features have been ruled out because either: 1) no major depressive or manic episodes have occurred concurrently with the active-phase symptoms, or 2) if mood episodes have occurred during active-phase symptoms, they have been present for a minority of the total duration of the active and residual periods of the illness.

Criterion E

The disturbance is not attributable to the physiological effects of a substance (e.g., a drug of abuse, a medication) or another medical condition.

Criterion F

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 one month (or less if successfully treated).

Entitlement considerations

In this section

Section A: Causes and/or aggravation

Section B: Medical conditions which are to be included in entitlement/assessment

Section C: Common medical conditions which may result, in whole or in part, from schizophrenia and/or its treatment

Section A: Causes and/or aggravation

Causal or aggravating factors versus predisposing factors

Causal or aggravating factors directly result in the onset or aggravation of the claimed psychiatric condition.

Predisposing factors make an individual more susceptible to developing the claimed condition. They are experiences or exposures which affect the individual's ability to cope with stress. For example, severe childhood abuse may be a predisposing factor in the onset of a significant psychiatric condition later in life. These factors do not cause a claimed condition. Partial entitlement should not be considered for predisposing factors.

Physical/constitutional symptoms are prevalent in people living with psychiatric diagnoses and are often associated with psychological distress. Physical and mental health symptoms frequently co-occur. Physical symptoms associated with psychiatric conditions are included in entitlement/assessment. However, once a symptom has developed into a separate and distinct diagnosis, the new diagnosis becomes a separate entitlement consideration.

For Veterans Affairs Canada (VAC) entitlement purposes, the following factors are accepted to cause or aggravate schizophrenia, and may be considered along with the evidence to assist in establishing a relationship to service. The factors have been determined based on a review of up-to-date scientific and medical literature, as well as evidence-based medical best practices. Factors other than those listed may be considered, however consultation with a disability consultant or medical advisor is recommended.

The timelines cited below are for guidance purposes. Each case should be adjudicated on the evidence provided and its own merits.

Factors

  1. Experiencing the death of a related child (biological, adopted, step or foster child) within the five years before the clinical onset or aggravation of schizophrenia.
  2. Experiencing the early death of a parent (before the individual is 18 years old) within the ten years before the clinical onset of schizophrenia.  
  3. Having a substance use disorder, involving cannabis, within the ten years before the clinical onset of schizophrenia.
  4. Using cannabis at least twice a week for a continuous period of at least six months before the age of 18 years, within the ten years before the clinical onset of schizophrenia.
  5. Having a clinically significant psychiatric condition at the time of the aggravation of schizophrenia. A clinically significant psychiatric condition as defined by the DSM-5-TR is a syndrome characterized by clinically significant disturbance in an individual’s cognition, emotion, regulation, or behaviour that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning.
  6. Directly experiencing a traumatic event(s) within the six months before the aggravation of schizophrenia.

    Traumatic events include, but are not limited to:

    • exposure to military combat
    • threatened or actual physical assault
    • threatened or actual sexual trauma
    • being kidnapped
    • being taken hostage
    • being in a terrorist attack
    • being tortured
    • incarceration as a prisoner of war
    • being in a natural or human-made disaster
    • being in a severe motor vehicle accident
    • killing or injuring a person
    • experiencing a sudden, catastrophic medical incident.
  7. In-person witnessing of a traumatic event(s) as it occurred to another person(s) within the six months before the aggravation of schizophrenia.

    Witnessed traumatic events include, but are not limited to:

    • threatened or serious injury to another person
    • an unnatural death
    • physical or sexual abuse of another person
    • a medical catastrophe in a close family member or close friend.
  8. Experiencing repeated or extreme exposure to aversive details of a traumatic event(s) within the six months before the aggravation of schizophrenia.

    Exposures include, but are not limited to:

    • viewing and/or collecting human remains
    • viewing and/or participating in the clearance of critically injured casualties
    • repeated exposure to the details of abuse and/or atrocities inflicted on another person(s)
    • dispatch operators exposed to violent or accidental traumatic event(s).

    Note: If the exposure under factor eight is to electronic media, television, movies and pictures, the exposure must be work related.

  9. Living or working in a hostile or life-threatening environment for a period of at least four weeks before the aggravation of schizophrenia.

    Situations or settings which have a pervasive threat to life or body including but not limited to:

    • being under threat of artillery, missile, rocket, mine or bomb attack
    • being under threat of nuclear, biologic or chemical agent attack
    • being involved in combat or going on combat patrols.
  10. Inability to obtain appropriate clinical management of schizophrenia.

Section B: Medical Conditions which are to be included in entitlement/assessment

Section B provides a list of diagnosed medical conditions/categories which are considered, for VAC purposes, to be included in the entitlement and assessment of schizophrenia.

Note:

  • If specific conditions are listed for a category, only those conditions are included in the entitlement and assessment of schizophrenia. Otherwise, all conditions within the category are included in the entitlement and assessment of schizophrenia.
  • Separate entitlement is required for a DSM-5-TR condition not included in Section B of this EEG.
  • Somatic symptom and related disorders, such as functional neurological symptom disorder (conversion disorder), somatic symptom disorder, illness anxiety disorder, and bodily distress disorder (ICD-11 diagnosis) are entitled separately and assessed on individual merits.

Section C: Common medical conditions which may result, in whole or in part, from schizophrenia and/or its treatment

Section C is a list of conditions which can be caused or aggravated by schizophrenia and/or its treatment. Conditions listed in Section C are not included in the entitlement and assessment of schizophrenia. A consequential entitlement decision may be considered where the individual merits and the medical evidence of the case support a consequential relationship. Conditions other than those listed in Section C may be considered; consultation with a disability consultant or medical advisor is recommended.

  • Tardive akathisia
  • Persistent medication-induced parkinsonism
  • Tardive dyskinesia.

If it is claimed a medication required to treat schizophrenia resulted in whole, or in part, in the clinical onset or aggravation of a medical condition the following must be established:

  • The medication was prescribed to treat schizophrenia.
  • The individual was receiving the medication at the time of the clinical onset or aggravation of the condition being claimed to the medication.
  • The current medical literature supports the medication can result in the clinical onset or aggravation of the condition being claimed to the medication.
  • The medication use is long-term, ongoing, and cannot reasonably be replaced with another medication or the medication is known to have enduring effects after discontinuation.

Note: Individual medications may belong to a class of medications. The effects of a specific medication may vary from the grouping. The effects of the specific medication should be considered.

Related VAC guidance and policy:

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