PATHOPHYSIOLOGIC PROBLEMS RELATED TO SCHIZOPHRENIA

Schizophrenia is a psychotic illness that can affect a person’s functional and cognitive ability, perception and expression of emotion. A psychotic illness is one where the individual’s mental state is disturbed to the extent that they have difficulty distinguishing external reality from their internal perceptions². Schizophrenia is perhaps best described as a syndrome that is identifiable by a cluster of signs and symptoms, which have diverse pathogenic bases³. The symptoms of schizophrenia can be debilitating in that they affect the person’s ability to think, to concentrate, to relate, and to function in usual day-to-day activities. The symptoms can be divided into two groups: positive and negative. Positive symptoms include disorders of thinking and perception including delusions, hallucinations and bizarre behaviour. Negative symptoms include reduced levels of energy and motivation, attention deficit, blunted affect, passive social withdrawal and impairment in social functioning, loss of motivation, poverty of speech and poor rapport^2,4,5.

The criteria for diagnosing schizophrenia include the presence of characteristic symptoms:

The presentation of an acute episode of schizophrenia is often a critical event that requires an immediate and comprehensive response. People with schizophrenia also frequently suffer emotional symptoms, such as depression and anxiety. Suicidal ideation may be present, with 10% of people with schizophrenia completing suicide⁷.

A number of subtypes of schizophrenia have been identified. The Diagnostic and Statistical Manual of Mental Disorders⁶ identified five subtypes: paranoid, disorganised, catatonic, undifferentiated and residual. A number of biological researchers use subtypes of type I or positive schizophrenia, which has a preponderance of positive symptoms; and type II or negative schizophrenia, which has a preponderance of negative symptoms².

COURSE OF THE ILLNESS

The course of schizophrenia is often marked by a prodromal phase in which there may be changes in the person’s social behaviour. Some of these changes, particularly those of withdrawal, irritability and anger, moodiness, and loss of interest in appearance and social relationships, may seem to be related to age-specific behaviours in adolescence. Other symptoms during the prodromal phase may include depression, suspiciousness, anxiety, and sleep disturbance. The first episode of schizophrenia usually occurs between the late teens and early thirties. The trajectory of the illness is highly variable. It may be brief (up to 2 years) with remission, or may last much longer with residual symptoms. Around 25% of people with the illness have a full remission following one or more episodes⁵. Around one third of people with schizophrenia will have a recovery from the acute phase that is marked by fewer relapses and fewer hospitalisations for acute episodes than those who retain residual symptoms. While this group may still require ongoing treatment and support, they will be able to function in the community⁸. Positive symptoms of delusions and hallucinations and disorders of thinking predominate in the early episodes of the illness, but tend to decrease in intensity over time. Loss of social and work skills, self-care and relationships may feature in the residual phase.

Better outcome is associated with

Relapse following treatment is associated with

AGE OF ONSET AND INCIDENCE OF SCHIZOPHRENIA

The age of onset of schizophrenia peaks for men at 18–24 years, and peaks for women at 24–32 years. The overall lifetime prevalence for schizophrenia of 1% is the same for men and women; however, better outcome is related to older age at onset^2,4. The prevalence of schizophrenia has been shown to be similar across gender, race, religion, population density, and level of industrialisation⁷.

PATHOPHYSIOLOGY OF SCHIZOPHRENIA

The early descriptions of schizophrenia by Kraepelin and Bleuler in the early 1900s described it as a biological disorder¹⁰. Later theories ventured into psychological and familial explanations, focusing attention on the psychology of the person, or family communication. These explanations have not been supported by scientific studies and recent research has focussed on genetics, brain pathology and brain chemistry.

VULNERABILITY-STRESS MODELS

The biological defects related to genetic factors, brain pathology and biochemical changes, while showing consistent and strong association with schizophrenia, are not a sufficient condition for the occurrence of the disorder¹⁶. The occurrence of a particular mental disorder in a particular individual needs to be understood by the presence of interacting biological, psychological, and social factors. The vulnerability-stress model is based on the understanding that a certain percentage of the population will, because of particular genetic and brain development factors, be vulnerable to schizophrenia. In certain psychological and environmental conditions, this vulnerability will be expressed as an episode of schizophrenia. Having a vulnerability to schizophrenia does not necessarily imply that the person will develop an episode of the disorder. Whether or not the person will experience the disorder, and whether or not the person will suffer relapses of the disorder, is dependent upon

These three factors interact, thus providing a model for aetiology of schizophrenia that recognises biological, psychological and sociological influences^5,16.

TESTS TO CONFIRM SCHIZOPHRENIA

While changes in brain structure and chemistry have been identified as vulnerability factors related to schizophrenia, there is no specific biological marker, and thus no biochemical test or brain scan that can identify schizophrenia at this point in time¹⁷.

NURSING IMPLICATIONS

The diagnosis of schizophrenia is made by careful and comprehensive psychological and biological assessment including assessment of presenting problems, history of the illness, premorbid personality and functioning, corroborating information, family history, and observation. The presence of delusions, hallucinations, disorganised speech and behaviour are characteristic symptoms of acute psychosis that may indicate a schizophrenic process. Positive symptoms tend to fluctuate over time and the client may be unwilling to discuss delusional material until there is a level of trust. The negative symptoms of loss of interest, withdrawal, anergia, poverty of speech, poor self-care and a blunted emotional response may be observed. The person presenting with a range of symptoms indicative of schizophrenia may also present with high levels of anxiety, depression, or aggressive responses related to delusional material. There is a high level of substance misuse and dependency in people presenting with schizophrenia⁸.

TREATMENT

Treatment for schizophrenia involves a combination of pharmacological and psychotherapeutic interventions^5,18. Early treatment of schizophrenia is important. The duration of untreated psychosis has been associated with cognitive deterioration. Early treatment may increase the likelihood of symptomatic relief, reduce cognitive deficits¹⁹, and decrease the adverse effects on family and social networks²⁰. The place of treatment needs to be assessed in light of the person’s safety, the ability of the family to provide containment and support, and the availability of community mental health services. Hospitalisation should be considered if there is any concern for the safety of the person, family and community.

PHARMACOLOGY

Drugs, which aim to reduce the symptoms of schizophrenia, are called antipsychotics. Traditional antipsychotic drugs, such as chlorpromazine, haloperidol and trifluoperazine, block D2 receptors and have an effect on positive symptoms, but little effect on the negative symptoms that can have a significant impact on the person’s quality of life and functional status. These drugs may also produce sedation, emotional settling, and psychomotor slowing. In addition, these drugs have a range of peripheral and central nervous system side effects that range from minor effects, such as constipation and dry mouth, to chronic movement disorders and life-threatening neuroleptic malignant syndrome².

Atypical antipsychotic drugs such as olanzapine, risperidone, and quetiapine are much better tolerated, although patients taking these drugs still need monitoring for neuroleptic malignant syndrome, extrapyramidal and a range of other side effects, including significant weight gain. In addition, atypical antipsychotics have been significantly associated with the onset of diabetes mellitus²¹. This group of drugs is called atypical because of their difference from the earlier antipsychotic agents. The atypical antipsychotic agents differ in terms of their neurotransmitter and neuroreceptor activity and their effect on negative symptoms. These drugs have less effect on D2 receptors, but antagonise other dopamine and serotonin receptor sites. They are being increasingly favoured in clinical practice. First-episode psychosis is usually treated with one of the atypical antipsychotic drugs. Monitoring of effectiveness includes observation of both positive and negative symptoms. An anxiolytic, such as diazepam, can be added in the short term to reduce distress levels of anxiety, agitation and insomnia. Monitoring for side effects includes observation for signs of dystonia (impaired muscle tone, often in the head, neck and tongue) shaking, stiffness and restlessness. Physical observations should include temperature, blood pressure and pulse as medication may alter cardiovascular function or have toxic effects. In the longer term, maintenance doses of atypical antipsychotics can be used, with continued monitoring. Clozapine may be effective when other treatments have failed. The use of clozapine is limited to registered centres, and in addition to the previously mentioned adverse effects, there is need to monitor for the severe adverse effects of neutropenia, agranulocytosis, and myocarditis^2,20.

PSYCHOTHERAPY

Psychotherapeutic treatment is as important to recovery from a psychotic illness as medication. An episode of schizophrenia can render the person’s view of themselves and their world as confusing, unreliable and chaotic. At the very least, the person needs someone who is empathetic and knowledgeable about the illness and the human response to the illness, about the pharmacological treatments and about recovery.

COGNITIVE BEHAVIOURAL TECHNIQUES

Cognitive behavioural techniques have proved effective in teaching coping skills for the management of symptoms of schizophrenia and the development of problem-solving responses. A more detailed discussion of cognitive behavioural therapy is included later in this chapter. Trygstad et al. demonstrated that behavioural management of persistent auditory hallucinations was clinically effective²². Rector and Beck reviewed studies of cognitive behavioural therapy and schizophrenia and concluded that cognitive behavioural therapy, in conjunction with pharmacology and other psychosocial treatments, improves outcomes of treatment of positive and negative symptoms²³.

Further interventions are considered in the section on Nursing Implications at the end of this chapter.

PREVALENCE, NATURAL HISTORY AND COURSE OF DEPRESSION

Depression is disconcertingly prevalent in the community, an observation that has been confirmed by the findings of a number of large-scale epidemiological studies conducted internationally. In Australia, the National Survey of Mental Health and Wellbeing estimated that some 5.8% of the adult population (or approximately 778,000 adults) had an identifiable depressive disorder in the 12 months prior to the survey³⁰. The National Co-morbidity Survey, a second large survey of the epidemiology of mental disorders in the USA, found the overall lifetime rate of major depressive episode to be 17.1% (12.7% among males, and 21.3% among females)³¹.

Differences in the prevalence rates reported between epidemiological studies are likely to be accounted for by differing methodologies employed in each study, for example the use of different survey questionnaires. However, it can be stated with some confidence that between 5 and 10% of the adult population will experience a major depressive episode in a 12-month period²⁶.

Depression frequently co-occurs with other mental disorders, for example anxiety symptoms or disorders occur in approximately 30% of patients with depression, and approximately 30% of people with depression experience panic attacks³². There are a number of medical illnesses where depression is a frequent concomitant condition, or where there seems to be evidence of the primary medical illness precipitating depression – either through a biologically mediated process and/or due to the stress associated with chronic, disabling or life-threatening illness. The incidence of depression among medically ill populations has been found to be as high as 15%³³. Medical illnesses or syndromes where there is evidence of an association with depression include, but are not limited to, the list in Table 16.1.

TABLE 16.1 SOME MEDICAL ILLNESSES OR SYNDROMES ASSOCIATED WITH DEPRESSION

The average age of onset of major depressive disorder is in the late 20s; however, depression can occur at any age³⁴, with depression in the elderly and childhood depression being common and sometimes under-recognised by health professionals^35,36. The onset of symptoms of major depression can be insidious, with symptoms increasing in frequency and severity over several weeks or months, or onset can be sudden. The duration of an episode of major depression is variable, lasting from weeks to years. Left untreated an episode of major depression can last for six to nine months^34,37.

While many people experience only a single episode of major depression and recover fully, approximately 50–85% of people will experience subsequent episodes of major depression³⁸. Approximately 20% of people who experience a major depressive episode will experience a relapse within 12 months³⁹, an important consideration for planning preventative treatment, such as maintenance antidepressant medication or ‘booster sessions’ where psychological treatment has been used.