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CDHO Advisory: Psychosis and Schizophrenia









Use of the dental hygiene interventions of scaling of teeth and root planing including curetting surrounding tissue, orthodontic and restorative practices, and other invasive interventions for persons1 with psychosis and schizophrenia.


Cite as College of Dental Hygienists of Ontario, CDHO Advisory Psychosis and Schizophrenia, 2023-06-05


Scaling of teeth and root planing including curetting surrounding tissue, orthodontic and restorative practices, and other invasive interventions (“the Procedures”).



Psychosis and schizophrenia


Advanced practice nurses
Dental assistants
Dental hygienists
Health professional students Nurses
Public health departments
Regulatory bodies


To guide dental hygienists at the point of care relative to the use of the Procedures for persons who have psychosis and schizophrenia, chiefly as follows.

  1. Understanding the medical condition.
  2. Sourcing medications information.
  3. Taking the medical and medications history.
  4. Identifying and contacting the most appropriate healthcare provider(s) for medical advice.
  5. Understanding and taking appropriate precautions prior to and during the Procedures proposed.
  6. Deciding when and when not to proceed with the Procedures proposed.
  7. Dealing with adverse events arising during the Procedures.
  8. Keeping records.
  9. Advising the patient/client.


Child (2 to 12 years)
Adolescent (13 to 18 years)
Adult (19 to 44 years)
Middle Age (45 to 64 years)
Aged (65 to 79 years)
Aged 80 and over
Parents, guardians, and family caregivers of children, young persons and adults with psychosis and schizophrenia.


For persons who have psychosis and schizophrenia: to maximize health benefits and minimize adverse effects by promoting the performance of the Procedures at the right time with the appropriate precautions, and by discouraging the performance of the Procedures at the wrong time or in the absence of appropriate precautions.



Terminology used in this Advisory

Resources consulted

Nomenclature varies among clinical centres. The following reflects common though not necessarily universal usages.

  1. Psychosis, psychoses, and psychotic disorders are mental experiences of psychotic episodes in which there is a distortion of or loss of contact with reality and which
    1. commonly include
      1. disorganization of behaviour and thinking
      2. delusions
      3. hallucination
    2. occur with various conditions, including schizophrenia.
  2. Schizophrenia is a severe, complex, chronic and disabling mental illness characterized by
    1. psychosis and psychotic episodes
    2. abnormal thinking
    3. deterioration in occupational, interpersonal and self-supportive abilities
    4. flattened emotions
    5. loss of contact with reality.

Other terminology is as follows.

  1. Concurrent disorder
    1. an alternative term for comorbidity specific to psychiatry
    2. the condition when a psychiatric disorder co-exists with a substance-use disorder and/or a gambling disorder.
  2. Delusions, fixed, false beliefs that
    1. are inconsistent with the person’s culture
    2. are misinterpretations of events and their significance
    3. have no basis in fact
    4. imply the person is
      1. being spied on
      2. having his or her thoughts listened to
      3. having his or her body controlled by external, hostile forces
      4. receiving thoughts that are implanted in his or her mind
      5. under threat of harm.
  3. Hallucinations, disturbances of perception which involve
    1. hearing voices, the most common hallucination, that comment on behaviour, are insulting or give commands
    2. seeing, tasting, smelling or feeling something that has no basis in reality.
  4. Psychotic episodes, experiences over periods of time
    1. when symptoms of psychosis may be strong enough to
      1. create a medical or other emergency
      2. interfere with the normal life of the person by variously affecting
        1. behaviour even to the extent of self-harm or violence
        2. mood
        3. thoughts
        4. sensations
    2. which vary
      1. among persons and episodes
      2. in duration
        1. from a few hours to days
        2. continuing indefinitely pending appropriate treatment and support
    3. which have three phases
      1. pre-psychotic, comprising
        1. changes in the way feelings, thoughts and perceptions are described
        2. early indications that are vague, variously including
          1. anxiety
          2. decreased motivation
          3. depressed mood
          4. deterioration in functioning
          5. odd beliefs or magical thinking
          6. reduced concentration
          7. sleep disturbance
          8. suspiciousness
          9. withdrawal from family, friends and social life
      2. full psychotic phase, characterized by
        1. symptoms and signs of psychotic episodes
        2. distress caused by the symptoms
        3. behaviour so out of character that family members
          1. become deeply concerned
          2. seek help
      3. treated psychosis, recovery with treatment in which
        1. recurrence remains a risk even though, for some persons, there may be no recurrence of the first episode of psychosis
        2. some of the symptoms of the full psychotic phase may linger.
  5. Schizophrenia phases, which
    1. cycle frequently or infrequently throughout the illness
    2. comprise
      1. schizophrenia prodromal phase, which
        1. may last weeks or months
        2. is characterized by
          1. confusion
          2. listlessness and apathy
          3. loss of interest in usual activities
          4. preference for being alone
          5. preoccupations with religion or philosophy
          6. problems concentrating
          7. withdrawal from friends and family members
      2. psychotic episodes, which are often frightening to the person and others
      3. schizophrenia residual phase, which
        1. resembles the schizophrenia prodromal phase
        2. is characterized by
          1. listlessness
          2. trouble concentrating
          3. withdrawal from friends and family members.

Overview of psychosis and schizophrenia

Resources consulted

Occurrence of psychosis


  1. is more common than is widely believed
  2. about 3 percent of all individuals experience a psychotic episode in their lifetime
  3. affects males and females equally, though women
    1. seem to be affected at a later age than men
    2. appear to respond better than men to most treatments
    3. are at increased risk of relapse
      1. during the premenstrual phase of the menstrual cycle
      2. after childbirth
      3. during or around the menopause
  4. occurs in all cultures and at all socioeconomic levels
  5. is more likely to occur where there is a family history of serious mental illness
  6. occurs in
    1. adolescence or early adulthood as first episodes, which
      1. may signal onset of schizophrenia or other serious conditions
      2. are challenging for diagnosis because of the wide range of conditions that it may herald
      3. require thorough medical assessment at an early stage
      4. are often alarming, disorienting and distressing for the person, and the family and associates
      5. vary in the duration, lasting
        1. only a few days when induced by substances or alcohol
        2. indefinitely until treated when caused by schizophrenia or bipolar disorder (CDHO Advisory)
    2. childhood, though not commonly, and may signal risk factors
  7. if left untreated, worsens and severely disrupts the lives of the person and the family.

Cause of psychosis


  1. lacks a single, clearly defined cause, though is believed linked with biochemical imbalance in the brain
  2. has causes that include
    1. drugs and medications
      1. alcohol and certain drugs of abuse, during use and withdrawal (CDHO Advisory)
      2. some prescription drugs, such as steroids and stimulants
    2. brain tumors or cysts
    3. dementia
    4. degenerative brain diseases, such as
      1. Parkinson’s disease (CDHO Advisory)
      2. Huntington’s disease
    5. HIV/AIDS (CDHO Advisory) and other infections that affect the brain
    6. some types of epilepsy (CDHO Advisory)
    7. stroke (CDHO Advisory)
  3. also occurs as an associated condition of various psychiatric disorders.

Risk factors of psychosis

Psychosis may

  1. prevent persons from functioning normally and caring for themselves
  2. if left untreated cause persons to harm themselves or others
  3. create a medical or other emergency when the person
    1. loses contact with reality
    2. engages in potentially self-injurious or dangerous behaviour
  4. signal the onset of psychiatric conditions that require prompt medical attention
  5. signal risk factors for conditions such as schizophrenia and bipolar disorder (CDHO Advisory), such as
    1. considerable social impairment
    2. family history of mental illness
    3. high levels of suspicion or paranoia
    4. high levels of unusual thoughts
    5. history of substance abuse
    6. recent deterioration in functioning.

Signs and symptoms of psychosis

Psychosis presents signs and symptoms that

  1. may be first detected by family or healthcare or other professionals because the person may not perceive the nature or significance of the symptoms
  2. may develop
    1. gradually, causing early-stage symptoms to be dismissed or ignored
    2. suddenly and obviously to the person, and to family, friends and associates
  3. are broadly categorized as obvious signs and symptoms, which include
    1. delusions, especially reflected in unfounded fears or suspicions
    2. hallucinations
    3. disorders of
      1. behaviour, which may become
        1. disorganized to a degree sufficient to impair activities of daily living, including
          1. caring for self
          2. dressing appropriately
          3. keeping appointments
          4. maintaining oral hygiene
          5. planning the day and following through with tasks previously easily performed as part of normal life
          6. preparing even simple meals
        2. dangerous to
          1. self through
            1. suicide
            2. self-injury
          2. others through violence
      2. mood, reflected in
        1. depression accompanied by
          1. thoughts of death or suicide
          2. withdrawal from social activity
        2. difficulty in expressing feelings
        3. inappropriate or intense outbursts of emotion
        4. flatness of emotions
      3. thought and thinking patterns, manifested by
        1. difficulty concentrating
        2. difficulty communicating with other people
        3. disconnected thoughts that
          1. are confused
          2. appear to vanish temporarily
          3. cause the person to randomly jump from subject to subject
            1. in thinking
            2. in speaking
        4. thoughts of depression and anxiety reflective of the prevailing mood
        5. loss of memory
  4. manifest as psychotic episodes
  5. may be experienced by the person as symptoms such as
    1. belief that others can manipulate his/her thoughts, or that s/he can manipulate the thoughts of others
    2. change from usual behaviour
    3. confused or disorganized thoughts
    4. deterioration in work or study
    5. excessive suspiciousness
    6. feeling of being ‘changed’ in some way
    7. loss of energy or motivation
    8. paranoid thoughts
    9. perceptions of voices or visions perceptible to no one else
    10. preoccupations with unusual or bizarre ideas
    11. thoughts that are too fast or too slow
    12. withdrawal from friends or family
  6. may be manifested by signs that
    1. are apparent to the person’s family, friends and associates
    2. vary widely from person to person and may change over time, including
      1. abnormal displays of emotion
      2. acknowledgement by the person of
        1. hallucinations
        2. confusion
        3. delusions
        4. depression
      3. disorganized thought and speech
      4. illusions
      5. loss of touch with reality
      6. mania
      7. suicidal tendency
      8. unfounded fear or suspicion.

Medical investigation of psychosis

Psychosis is

  1. investigated with psychiatric evaluation and medical testing, including
    1. blood tests for
      1. abnormal electrolyte and hormone levels
      2. HIV/AIDS (CDHO Advisory) and other infections
    2. screening for substances of abuse (CDHO Advisory)
    3. MRI examination of the brain
  2. is challenging for diagnosis because psychotic reactions
    1. are to some degree within normal human experience
    2. occur as symptoms of various distinct mental and physical disorders, such as
      1. schizophrenia in which psychotic symptoms
        1. last for at least six months
        2. are accompanied by a significant decline in ability to function
      2. bipolar disorder (CDHO Advisory) in which symptoms pertain to mood disturbance rather than thought disturbance
      3. depression (CDHO Advisory) with psychotic features
      4. substance-induced psychosis associated substances such as
        1. alcohol
        2. amphetamines
        3. cocaine
        4. LSD
        5. marijuana
      5. psychosis associated with physical illness or head injury
      6. brief psychotic disorder, also called reactive psychosis, which
        1. lasts less than a month
        2. is often triggered by major stress such as a death in the family
      7. delusional disorder, powerful and persistent beliefs in things without basis in reality.

Treatment of psychosis

Psychosis, which is treatable but curable only when the cause is recognizable and curable, requires

  1. prompt treatment for the best long-term outcome
  2. treatment that variously comprises
    1. hospitalization
    2. antipsychotic medication to
      1. relieve symptoms of psychosis in the acute phase to reduce the possibility of harm to self or others
      2. help prevent further psychotic episodes
    3. psychosocial interventions, such as counseling.

Prevention of psychosis

Psychosis prevention is directed at the cause when this is recognizable and correctable.

Prognosis of psychosis


  1. depends on the extent to which the cause is recognizable and correctable
  2. is improved by appropriate treatment, which includes medications, education and support
    1. with which a first episode
      1. may be followed by full recovery
      2. may never recur
    2. which may be required life-long for control of symptoms.

Social considerations of psychosis

Psychosis highlights education and support for the person and family caregivers that is

  1. aimed at allowing the person to maintain daily routines as much as possible
  2. delivered with the recognition that, without effective treatment, education and support, psychosis can overwhelm the lives of families as well as persons with the condition.

Occurrence of schizophrenia


  1. affects
    1. men and women, and persons of all races, cultures, and social classes, and exists world-wide
    2. an estimated 1 percent of the Canadian population, for a total of about 380,000 persons
  2. occurs most often in the age range 16 to 30 years, and also in children after the age of 5, though rarely, and may resemble other disorders of childhood such as autism (CDHO Advisory)
  3. is the greatest disabler of young persons
  4. is a complex illness which is regarded by some authorities as a group of several different illnesses with similar symptoms and signs
  5. may occur
    1. gradually, with first symptoms that initially may seem more bewildering than serious
    2. suddenly and develop rapidly
  6. has three phases
  7. was previously classified by the American Psychiatric Association (prior to the fifth edition of Diagnostic and Statistical Manual of Mental Disorders, which acknowledged that schizophrenia exists on a spectrum of presentations) as
    1. paranoid schizophrenia, characterized by hallucinations with or without delusions, which usually are of persecution
    2. hebephrenic (disorganized) schizophrenia, characterized by
      1. confusion and strange ideas
      2. disorganized behaviour and speech
      3. inappropriate responses
      4. moodiness
      5. muted emotion
      6. poor concentration
    3. catatonic schizophrenia, characterized by effects on mobility, which may
      1. be excessive
      2. be impaired
      3. include unusual postures
    4. undifferentiated schizophrenia
    5. residual schizophrenia

Cause of schizophrenia


  1. lacks a single known cause
  2. is believed to involve some type of genetic mutation but whether schizophrenia is inherited or whether alternatively it results from genetic mutation that occurs after fertilization of the ovum remains the subject of intense research
  3. may originate in faulty development of neurons in the fetal brain.

Risk factors of schizophrenia

Schizophrenia risk

  1. increases the likelihood of attempts at suicide, compared to persons without schizophrenia: suicide risk is a medical emergency
  2. may be increased by
    1. drugs of misuse and alcohol (CDHO Advisory) because these can
      1. impair the action of antipsychotic medications
      2. worsen schizophrenia symptoms; marijuana is an example
      3. undermine compliance with treatment plans
    2. cigarette smoking because the withdrawal symptoms that result from quitting may temporarily exacerbate schizophrenia.

Signs and symptoms of schizophrenia


  1. is accompanied by troublesome signs and symptoms which
    1. differ in nature and vary in severity from person to person
    2. may be classified as
      1. psychotic episodes, sometimes called positive symptoms because these bring ‘add-in’ symptoms during the development of the episodes
      2. negative symptoms, subtractions from the range of feelings usual for the person, which
        1. occur once psychosis is stabilized
        2. include loss of
          1. energy
          2. interest
          3. motivation
          4. sense of humour
          5. warmth
      3. cognitive symptoms, which
        1. occur once a psychosis is stabilized
        2. include
          1. disorganized thoughts
          2. memory problems
          3. difficulty
            1. concentrating
            2. following instructions
            3. planning
            4. making decisions
            5. completing everyday tasks, such as
              1. self-care generally
              2. oral hygiene
              3. dressing appropriately
              4. preparing simple meals
      4. emotional symptoms, which
        1. occur once a psychosis is stabilized
        2. include
          1. depression
          2. difficulty expressing feelings
          3. dulled emotions
          4. inappropriate emotions
      5. physical symptoms of an inexplicable or strange nature
  2. may be associated with
    1. violence, which occurs
      1. only in a minority of persons with schizophrenia
      2. usually at home with family members
    2. suicide risk.

Medical investigation of schizophrenia

Schizophrenia lacks a definitive diagnostic test.

Treatment of schizophrenia


  1. becomes a medical emergency when the person
    1. hears voices telling him or her to hurt himself or herself, or others
    2. feels the urge to hurt himself or herself, or others
    3. is feeling hopeless or overwhelmed
    4. is seeing things that are not present or which have no existence
    5. feels unable to leave the house
    6. is unable to care for self
  2. lacks a cure, but can be controlled by
    1. medication, including antipsychotics, which
      1. act against the psychotic symptoms of illnesses such as schizophrenia
      2. cannot cure the illness, but they can remove or reduce the symptoms
      3. may abbreviate a psychotic episode
      4. have various side effects
      5. are generally effective for schizophrenia; they
        1. act rapidly in controlling important symptoms, but all have side-effects
        2. differ in the dosage prescribed to produce therapeutic effects, and are selected carefully for the individual person
    2. psychosocial treatments, which
      1. help persons
        1. cope with their condition from day to day
        2. find medication that suits them
      2. include
        1. drug and alcohol treatment, often combined with other treatments for schizophrenia
        2. family education
        3. illness management skills
        4. rehabilitation for
          1. employment
          2. living skills
        5. support groups
        6. psychotherapy.

Prevention of schizophrenia

Schizophrenia lacks a cure or means of prevention, but does respond to treatment provided that this is complied with.

Prognosis of schizophrenia

Schizophrenia prognosis

  1. is difficult to predict because
    1. symptoms often improve to the point at which persons with condition are able to function independently in the community if they are
      1. consistent in their compliance with medication
      2. supported in housing
      3. supported with appropriate psychosocial services
    2. some persons
      1. are at risk for repeated episodes, especially during the early stages of the illness
      2. may need supported housing, job training, and other community support programs.
      3. may not be able to live alone, and so require group homes or other long-term, structured accommodation
  2. generally is best when diagnosis
    1. has been early
    2. treatment began promptly
    3. medication has been complied with.

Social considerations of schizophrenia


  1. poses particular challenges for the person in
    1. accepting the importance of compliance with medication
    2. avoiding stress
    3. continuing at school
    4. establishing and maintaining relationships
    5. finding a job and a place to live
    6. having a social life
    7. overcoming stigmatization and prejudice
  2. requires involvement of family caregivers who
    1. support the person affected with continuity that encourages appropriate communication
    2. learn about
      1. psychotic episodes
      2. schizophrenia
    3. work closely with healthcare professionals
    4. provide information useful to healthcare professionals
    5. often experience a heavy and at times unbearable emotional, social and financial burden which
      1. affects the family and the person
      2. may increase the risk of suicide on the part of the person
    6. are increasingly involved with collaborative healthcare delivery
  3. draws heavily on support groups and programs, which, among other things, help the family caregiver to help the person
    1. take medications correctly and manage side effects
    2. notice the early signs of a relapse and understand what to do if symptoms return
    3. cope with symptoms that occur even when medication is being taken
    4. manage money
    5. use public transportation.

Comorbidity, complications and associated conditions

Comorbid conditions are those which co-exist with psychosis and schizophrenia but which are not believed to be caused by it. Complications and associated conditions are those that may have some link with it. Distinguishing among comorbid conditions, complications and associated conditions may be difficult in clinical practice. The range, complexity and variability of the effects of psychosis and schizophrenia, possibly complicated by delays in diagnosis, create particular difficulties in differentiating among comorbidities and complications.

Resources consulted

  1. Some 50 to 80 percent of persons with schizophrenia are likely to experience a substance-use disorder in their lifetime, a concurrent disorder that is receiving increasing attention, through
    1. advancement in the treatment of co-occurring schizophrenia and substance use disorders
    2. increasing emphasis on the importance of support for families and family caregivers, among others, in addressing substance use disorders involving persons with a mental illness
    3. recognition that failure to simultaneously treat the mental illness, such as schizophrenia, and the substance use disorder delays or derails recovery
    4. highlighting best practices, service gaps and support needs faced by family members, family caregivers and service providers.
  2. Comorbid conditions, complications and associated conditions for psychosis and schizophrenia include conditions that harm health and are linked with substance abuse, smoking, inadequate diet, poor compliance with medications and multiple remissions and relapses, and poor health generally include
    1. cardiac disease (CDHO Advisory)
    2. diabetes (CDHO Advisory)
    3. emphysema (CDHO Advisory)
    4. lung cancer (CDHO Fact Sheet)
    5. oral cancer (CDHO Advisory).
  3. Comorbid conditions, complications and associated conditions for psychosis and schizophrenia
    1. include
      1. bipolar disorder (CDHO Advisory)
      2. brain tumors (CDHO Advisory)
      3. delusional disorder
      4. dementia (CDHO Advisory)
      5. depression (CDHO Advisory) with psychotic features
      6. dependence on alcohol, certain drugs of abuse and medications (CDHO Advisory)
      7. epilepsy (CDHO Advisory)
      8. Parkinson’s disease (CDHO Advisory)
      9. personality disorders
      10. psychotic depression
      11. stroke (CDHO Advisory)
    2. arise because of
      1. inactive lifestyle
      2. side effects of medications
      3. the person’s inability to communicate with healthcare providers, leading to inadequate medical care.

Oral health considerations

Resources consulted

  1. Oral healthcare
    1. is an appropriate treatment for schizophrenia
    2. may need specialized services for persons with schizophrenia living in the community.
  2. Comparative population studies show that the dental health of persons with schizophrenia is relatively poor, involving
    1. high rates of dental caries and periodontal disease
    2. oral ulceration
    3. difficulty in speaking (which may also be a manifestation of schizophrenia)
    4. dysphagia
    5. thrush.
  3. The Procedures can be performed on persons with schizophrenia provided that the dental hygienist has a broad awareness of the condition and understands the particular factors that must be taken into careful consideration.
  4. Factors favouring oral disease include
    1. the person’s lack of ability or motivation for oral hygiene self-care
    2. substance abuse and smoking
    3. adverse effects of antipsychotic medications and their interactions with medications used
      1. in oral healthcare
      2. for concurrent disorders and comorbidities.
  5. Because the antipsychotic drug clozapine may cause bone marrow suppression, the Procedures should not begin until the dental hygienist is assured by the primary care physician that the white blood cell count is within normal limits.
  6. Among the factors favouring the independent life for persons with schizophrenia is good oral health.
  7. Throughout dental hygiene treatment, families will likely benefit from support and education about oral healthcare, with due regard to the particular challenges created by psychosis and schizophrenia, including problems with the person’s
    1. keeping and tolerating appointments, which may require increased frequency and reduced duration of appointments
    2. coping with the activities of daily living
    3. persisting with self-care including oral hygiene, which may be improved if the family caregiver is provided with appropriate instruction
    4. avoiding unhealthy behaviours such as
      1. poor nutritional habits
      2. smoking
      3. substance abuse.
  8. Factors requiring attention in providing oral healthcare to persons with psychosis and schizophrenia include
    1. the current status of the illness, whether in
      1. the residual phase, with the possibility of relapse provoked by stressful factors
      2. relapse, marked by re-emergence of psychotic manifestations, resulting in impairment of the person’s
        1. understanding of the Procedures and their importance
        2. ability to give valid consent for treatment
        3. cooperation during the Procedures
        4. compliance with oral healthcare advice and medical advice generally
        5. control over delusions and hallucinations, which may in bizarre ways involve the mouth
    2. communications, which should take account of the possibility that, for the person, spoken words and ordinary gestures may have acquired meanings comprehensible only to him or her, and therefore should as an alternative to the spoken word emphasize
      1. diagrams, colorful posters and use of mirrors to convey information and explanations
      2. modeled demonstrations in which the dental hygienist brushes and flosses his or her own teeth
      3. a large mirror for instruction on correct tooth brushing, flossing techniques and use of artificial saliva products, antimicrobial agents, and fluoride mouth rinses
      4. written instructions because these can be better organized than spoken exchanges
      5. specific communication protocols, such as refraining from
        1. engaging too closely in conversation if it takes a direction that is irrelevant or logically inconsistent with the matter at hand
        2. speaking as though the person is absent
        3. using words, phraseology or diction that, however unintentionally, may be perceived as teasing or mimicry
    3. stress, which if
      1. increased may provoke psychotic, unusual or difficult-to-manage reactions
      2. decreased may reduce the possibility of psychotic reactions
      3. unavoidable may require temporary increase in antipsychotic medication
    4. abnormal preoccupations, which may not be immediately evident to the oral healthcare professional, and which may interfere with oral healthcare and oral self-care
    5. abnormal behaviours, beliefs, movements and reflexes involving the mouth or face, such as
      1. abnormal gag reflex, creating the requirement for the airway to be carefully protected
      2. delusions
      3. dysphagia
      4. grimacing
      5. hallucinations
      6. self-injury
    6. circumstances in which the person is frightened, distressed or, rarely, potentially violent, which are avoided or responded to with measures such as implementing an office action plan for handling psychiatric emergencies that includes
      1. protocols for the emergency response
      2. telephone numbers of
        1. family and other caregiver(s)
        2. appropriate agencies and local mental health organizations
        3. emergency services
        4. family physician
    7. medication regimes
      1. that are consistent in that, when successfully established, they are unlikely to be changed or substituted, which facilitates the tracking of side-effects
      2. may have side-effects with consequences for the Procedures or other oral healthcare that must be treated or responded to directly; these include
        1. bone marrow suppression leading to low white blood cell counts
        2. dry mouth
        3. movement abnormalities
        4. mucosal lesions from yeast or other infections.


Sourcing medications information

  1. Adverse effect database
  2. Specialized organizations
  3. Medications considerations
    All medications have potential side effects whether taken alone or in combination with other prescription medications, or as over-the-counter (OTC) or herbal medications.
  4. Information on herbals and supplements
  5. Complementary and alternative medicine

Types of medications: psychosis and schizophrenia

  1. Persons with schizophrenia need to take medication indefinitely because vulnerability to psychotic episodes may never fully abate, even though some or all of the symptoms reduce or disappear.
  2. Antipsychotic medications comprise
    1. typical antipsychotics, the first generation of antipsychotic medications, which include
    2. atypical antipsychotics, the second generation of antipsychotic medications, which include
  3. In addition to antipsychotic medications other types may also be used to treat particular symptoms such as depression, anxiety or sleep difficulties.

Side-effects of medications

See the links above for side-effects and warnings about the individual medications.

Side-effects generally with antipsychotic medications

  1. are especially common during the psychotic episodes of schizophrenia during which the dose of medication may need to be raised temporarily
  2. may require additional medication to combat side effects
  3. vary among the antipsychotic medications, may subside in time, and include some combination of
    1. blurred vision
    2. changes in menstrual cycles
    3. decrease in libido
    4. dizziness
    5. drowsiness
    6. dry mouth
    7. muscle spasms
    8. muscular stiffness
    9. rapid heartbeat
    10. restlessness
    11. skin rashes
    12. tremor
    13. weight gain
  4. from long-term use of certain antipsychotic medications may include
    1. involuntary movements (tardive dyskinesia) of the face, eyes, tongue, mouth or jaw, that, through unceasing mandibular movements may cause
      1. dislodging of complete removable prostheses
      2. orofacial pain from mucosal ulcers
      3. fatigue of the masticatory muscles
    2. spasms of the jaw muscles that may cause
      1. dislocation of the temporomandibular joint
      2. impaired gag reflex
      3. increased incidence of death from obstructive asphyxia
    3. hyposalivation, caused by blocking the normal stimulation of the salivary glands, which favours periodontal disease and its consequences
    4. bone marrow suppression and blood count changes leading to ulcers and thrush infections in the mouth
  5. may discourage persons from persevering with medication though, over time, the side-effects may weaken
  6. with the atypical antipsychotic medications include
    1. excessive salivation, which is common with clozapine, and which can be severe, though it usually ceases after about two weeks following start of the medication
    2. increased risk for all-cause mortality, so that the antipsychotic medications are not approved or are subject to warnings for use in elderly demented patients
  7. include interactions with other medications such as
    1. anticonvulsants
    2. anticoagulants
    3. antihypertensives
    4. anxiolytics
    5. analgesics
    6. antidepressants
    7. medications used for Parkinson’s disease.
  8. include potentiation of the effects of central nervous system depressants such as
    1. alcohol
    2. antihistamines
    3. certain sleep medications
    4. narcotics.


The dental hygienist in taking the medical and medications history-taking should

  1. focus on screening the patient/client prior to treatment decision relative to
    1. key symptoms
    2. medications considerations
    3. contraindications
    4. complications
    5. comorbidities
    6. associated conditions
  2. explore the need for advice from the primary or specialized care provider(s)
  3. inquire about
    1. pointers in the history of significance to psychosis and schizophrenia, such as problems with previous dental/dental hygiene care or minor surgery
    2. symptoms indicative of relapse in the residual phase of schizophrenia
    3. the patient/client’s understanding and acceptance of the need for oral healthcare
    4. medications considerations, including over-the-counter medications, herbals and supplements
    5. problems with infections generally and specifically associated with dental/dental hygiene care
    6. the patient/client’s current state of health
    7. how the patient/client’s current symptoms relate to
      1. oral health
      2. health generally
      3. recent changes in the patient/client’s condition.


Identifying and contacting the most appropriate healthcare provider(s) from whom to obtain medical or other advice pertinent to a particular patient/client

The dental hygienist should

  1. record the name of the physician/primary care provider most closely associated with the patient/client’s healthcare, and the telephone number
  2. obtain from the patient/client or parent/guardian written, informed consent to contact the identified physician/primary healthcare provider
  3. use a consent/medical consultation form, and be prepared to securely send the form to the provider
  4. include on the form a standardized statement of the Procedures proposed, with a request for advice on proceeding or not at the particular time, and any precautions to be observed.


Infection Control

Dental hygienists are required to keep their practices current with infection control policies and procedures, especially in relation to

  1. the CDHO’s Infection Prevention and Control Guidelines (2022)
  2. relevant occupational health and safety legislative requirements
  3. relevant public health legislative requirements
  4. best practices or other protocols specific to the medical condition of the patient/client.


  1. Initiation of the Procedures is contraindicated if:
    1. the patient/client is not under medical management for psychosis or schizophrenia;
    2. the patient/client displays psychotic signs/symptoms that pose a risk to himself/herself or the dental hygienist during procedures (e.g., disorganized behaviour); or
    3. the patient/client is taking the antipsychotic drug clozapine, which may cause bone marrow suppression; the Procedures should not begin until the dental hygienist confirms with the patient/client’s physician that the white blood cell count is within normal limits.
  2. With an otherwise healthy patient/client whose symptoms are under control and whose treatment is proceeding normally, the dental hygienist should implement the Procedures, though these may be postponed pending medical advice, which may be required if the patient/client has
    1. awaits medical clearance regarding possible immunosuppression associated with the use of antipsychotic medication;
    2. has previously undiagnosed psychosis or schizophrenia;
    3. has suboptimally treated psychosis or schizophrenia (which can adversely affect informed consent, decision-making, and behaviour);
    4. exhibits psychotic signs/symptoms that may pose risk during, or cause inability to perform, Procedures;
    5. is medically unstable; in particular, malignant neuroleptic syndrome is a medical emergency;
    6. has not complied with pre-medication (e.g., sedative), when indicated and as directed by prescribing physician;
    7. has comorbidity, complication or an associated condition of psychosis and schizophrenia;
    8. has not recently or ever sought and received medical advice relative to oral healthcare procedures;
    9. has recently changed significant medications, under medical advice or otherwise;
    10. has recently experienced changes in his/her medical condition such as medication or other side effects of treatment;
    11. is deeply concerned about any aspect of his or her medical condition.
  3. The dental hygienist
    1. should be prepared to treat patients/clients whose psychosis or schizophrenia is under good control (and does adversely affect informed consent, decision-making, and behaviour nor pose risk for Procedures), even if the experience is time-consuming and stressful
    2. may need advice from the patient/client’s primary care physician to address uncertainties associated with providing oral healthcare to individual patient/clients.


Dental hygienists are required to initiate emergency protocols as required by the College of Dental Hygienists of Ontario’s Standards of Practice, and as appropriate for the condition of the patient/client.

First-aid provisions and responses as required for current certification in first aid.


Subject to Ontario Regulation 9/08 Part III.1, Records, in particular S 12.1 (1) and (2) for a patient/client with a history of psychosis and/or schizophrenia, the dental hygienist should specifically record

  1. a summary of the medical and medications history
  2. any advice received from the physician/primary care provider relative to the patient/client’s condition
  3. the decision made by the dental hygienist, with reasons
  4. compliance with the precautions required
  5. all Procedure(s) used
  6. any advice given to the patient/client.


The dental hygienists should

  1. urge the patient/client to alert any healthcare professional who proposes any intervention or test
    1. that he or she has a history of psychosis and schizophrenia
    2. to the medications he or she is taking
  2. should discuss, as appropriate, and with regard to communication requirements and, if required, information exchange with the family caregiver
    1. the importance of the patient/client’s
      1. self-checking the mouth regularly for new signs or symptoms
      2. reporting to the appropriate healthcare provider any changes in the mouth
    2. the need for regular oral health examinations and preventive oral healthcare
    3. oral self-care including information about
      1. choice of toothpaste
      2. tooth-brushing techniques and related devices
      3. dental flossing
      4. mouth rinses
      5. management of a dry mouth
    4. the importance of an appropriate diet in the maintenance of oral health
    5. for persons at an advanced stage of a disease or debilitation
      1. regimens for oral hygiene as a component of supportive care and palliative care
      2. the role of the family caregiver, with emphasis on maintaining an infection-free environment through hand-washing and, if appropriate, wearing gloves
      3. scheduling and duration of appointments to minimize stress and fatigue
    6. comfort level while reclining, and stress and anxiety related to the Procedures
    7. medication side effects such as dry mouth, and recommend treatment
    8. mouth ulcers and other conditions of the mouth relating to psychosis and schizophrenia, comorbidities, complications or associated conditions, medications or diet
    9. pain management.



  1. Promoting health through oral hygiene for persons who have psychosis and schizophrenia.
  2. Reducing the adverse effects, such as provocation of psychotic episodes or unusual or difficult-to-manage reactions, in persons who have psychosis and schizophrenia, by
    1. generally increasing comfort level in the course of dental hygiene interventions
    2. appropriate communication
    3. provision of advice on scheduling and duration of appointments.
  3. Reducing the risk that oral health needs are unmet.


  1. Causing or provoking psychotic, unusual or difficult-to-manage reactions
  2. Performing the Procedures at an inappropriate time, such as
    1. when the patient/client is unable to understand, give valid consent for, and cooperate with the Procedures
    2. in the presence of complications for which prior medical advice is required
    3. in the presence of acute oral infection without prior medical advice.
  3. Disturbing the normal medications and dietary routines of a person with psychosis and schizophrenia, or exacerbating resistance to medications compliance.
  4. Inappropriate management of pain or medication.






2011-10-01; 2018-11-05; 2023-06-05


College of Dental Hygienists of Ontario, regulatory body
Greyhead Associates, medical information service specialists


College of Dental Hygienists of Ontario


College of Dental Hygienists of Ontario, Practice Advisors


Dr Gordon Atherley
O StJ , MB ChB, DIH, MD, MFCM (Royal College of Physicians, UK), FFOM (Royal College of Physicians, UK), FACOM (American College of Occupational Medicine), LLD (hc), FRSA

Dr Kevin Glasgow

Lisa Taylor

Giulia Galloro

Carolle Lepage


The College of Dental Hygienists of Ontario gratefully acknowledges the Template of Guideline Attributes, on which this advisory is modelled, of The National Guideline Clearinghouse™ (NGC), sponsored by the Agency for Healthcare Research and Quality (AHRQ), U.S. Department of Health and Human Services.

Denise Lalande
Final layout and proofreading

© 2009, 2011, 2018, 2023 College of Dental Hygienists of Ontario


1 Persons includes young persons and children