CHAPTER 37—PSYCHOTIC DISORDERS
SCHIZOPHRENIA AND SCHIZOPHRENIA-LIKE SYNDROMES
PSYCHOTIC SYMPTOMS IN DELIRIUM
PSYCHOTIC SYMPTOMS IN MOOD DISORDER
PSYCHOTIC SYMPTOMS IN DEMENTIA
SYNDROMES OF ISOLATED HALLUCINATIONS
Psychotic symptoms are defined as either hallucinations, that is, perceptions without stimuli, or delusions, that is, fixed, false, idiosyncratic ideas. Hallucinations are abnormal perceptions that can be in any of the five sensory modalities (auditory, visual, tactile, olfactory, gustatory). Delusions are unfounded ideas that can be suspicious (paranoid), grandiose, somatic, self-blaming, or hopeless. This chapter focuses on conditions in which psychotic symptoms are prominent and central to making the diagnosis. It only briefly discusses other disorders, such as dementia, delirium, and the mood disorders, in which psychotic symptoms can occur but whose defining features are in the cognitive or mood realms and which are discussed elsewhere. (See Dementia; Delirium; Depression and Other Mood Disorders.)
Hallucinations and delusions occur in a variety of disorders. The evaluation of a person with hallucinations and delusions (Figure 37.1) should first evaluate for underlying sources such as delirium, dementia, stroke, or Parkinson’s disease. An acute onset of altered level of consciousness or inability to sustain attention suggests delirium. Next, a primary mood disorder should be considered. Only after other causes are excluded should the diagnosis of a schizophrenia-like state be made. It should be noted that delirium, most often superimposed on an underlying dementia, is the most common cause of new-onset psychosis in late life.
Schizophrenia is defined as a chronic psychiatric disorder characterized by positive symptoms (eg, hallucinations, delusions, and thought disorder) and negative symptoms (eg, social dilapidation and apathy). Mood disorder and cognitive disorder should be excluded. In men, schizophrenia has a modal onset at age 18; onset after age 45 years is uncommon. In women, on the other hand, modal age of onset is 28, and 20% to 30% of cases begin after age 45. Ten percent to 15% of cases of schizophrenia first come to clinical attention after patients have reached 59 years of age.
In older persons, schizophrenia-like conditions are characterized by onset after age 44, prominent persecutory (paranoid) delusions, and multimodal hallucinations. For example, patients commonly complain that items are being stolen or report that they are being persecuted unjustly. Hallucinations often manifest in complaints, for example, that a neighbor is persistently banging on walls or the roof, that someone is pumping gas under the door, or that electrical sensations are being sent through the walls of the person’s home and into his or her body. A schizophrenia-like psychosis can be diagnosed only when cognitive disorder, mood disorder, or other explanatory medical conditions such as delirium or focal brain pathology have been excluded (Figure 37.1).
The schizophrenia-like psychoses of late life differ from schizophrenia beginning in early life in two ways. First, thought disorder, a sign described as speech in which a series of thoughts are not connected to one another in a logical fashion, is much less common in elderly patients, comprising only 5% of cases. In early-onset schizophrenia, thought disorder is present in approximately 50% of cases. It is important to note that thought disorder in schizophrenia occurs in the absence of an impaired sensorium (ie, delirium). When illogical speech occurs in late life, a delirium or dementia should be excluded. A second significant difference is the rarity of social deterioration and dilapidation among elderly patients. Thus, personality is often intact in late-onset cases. However, there is a dearth of long-term follow-up studies, so it is unknown whether social deterioration and personality changes occur after many years of symptoms.
Late-onset schizophrenia is more common among women. The population-based incidence of late-onset schizophrenia is unknown, but the lifetime prevalence of schizophrenia is 1% among both men and women.
Late-onset schizophrenia-like psychoses affect predominantly women, with the female:male ratio ranging from 5:1 to 10:1. It has been speculated that later onset is due to decreasing natural estrogen levels, but there is little evidence to support this hypothesis. Many persons with late-onset schizophrenia-like psychosis have been able to hold responsible jobs and work efficiently, but premorbid isolation and “schizoid” (socially isolated personality) traits are common. Studies report greater degrees of brain white matter hyperintensities on magnetic resonance imaging scans in late-onset schizophrenia, a finding that suggests that brain vascular disease is a risk factor. However, this finding has not been adequately replicated, and other causes of white matter hyperintensities are plausible.
One condition that may be confused with late-onset schizophrenia is frontotemporal dementia (formerly referred to as Pick’s disease), as it may involve features of socially inappropriate and odd behaviors as well as premorbidly odd or “schizoid” personality features. (See Dementia.)
Because suspiciousness and paranoid delusions are commonly the most prominent symptoms, the physician’s first task in treating late-onset psychosis is often to establish a trusting therapeutic relationship with the patient. On occasion, the suspicious ideas are plausible (eg, the claim that the patient is being financially abused by a relative), but usually the delusions are bizarre and implausible. It is rarely effective to confront the patient with the unreality or implausibility of his or her ideas. The patient is more likely to respond positively if the physician empathizes with the distress that the symptoms cause (“I can see how upset you are by all of this”). If patients ask whether the physician “believes” them, a response such as, “I don’t hear anything like that, but I appreciate the fact that you do” is both honest and empathic. The symptoms are usually frightening and distressing to the patients and can lead to unusual behaviors. For example, patients who develop concerns that their food is being poisoned may exhibit unusual eating habits or food avoidance. Furthermore, suspiciousness can isolate the patient from friends and family. Therefore, encouraging patients to maintain important relationships and seeking their permission to discuss the source of symptoms with close family members or friends may help these patients maintain important, supportive relationships.
Clinical experience and descriptive case series suggest that antipsychotic drugs are as effective in late-onset schizophrenia as in early-onset cases. Most specialist physicians recommend the newer atypical antipsychotic drugs because they are less likely to cause tardive dyskinesia, a side effect for which older age is a predisposing factor. Doses should be increased at semi-weekly or weekly intervals, as needed. While doses are being titrated, patients should be monitored for the emergence of extrapyramidal side effects (parkinsonian tremor, rigidity, dystonia) and other movement disorders. These should be treated by lowering dosage and switching to an alternative antipsychotic if necessary. Polypharmacy should be avoided by reducing or switching antipsychotic medication rather than adding a medication for extrapyramidal symptoms. The more common side effects with quetiapine are sedation and orthostatic hypotension; with risperidone, extrapyramidal symptoms; and with olanzapine, weight gain and sedation (Table 37.1).
No studies are available to guide the length of treatment. Clinical experience suggests that patients who respond to antipsychotic medications should be continued on the minimal effective dose for at least 6 months. For patients who relapse on treatment or when the dosage is lowered, maintenance over a longer term (at least 1 to 2 years) is recommended. Patients should be monitored for the emergence of tardive dyskinesia, a syndrome characterized by repetitive involuntary movements of the oral and limb musculature. If tardive dyskinesia develops, the dosage of the antipsychotic agent should be lowered, if possible. Depending on the duration of exposure, tardive dyskinesia may worsen or appear when the antipsychotic is discontinued or the dose is lowered, or when switching from one antipsychotic to another. At the time antipsychotic drugs are initiated or as soon as symptoms improve enough so that the patient can understand the risk, he or she should be informed of the risk of tardive dyskinesia and the possibility that it can be irreversible.
Hallucinations, particularly visual hallucinations, can be a symptom of delirium, even when it is mild. The onset of delirium is usually acute, and there is often an identifiable metabolic or infectious cause. The mental status examination reveals multiple cognitive impairments and a diminished level of consciousness. (See Delirium.)
Delusions can be seen in major depression and in the manic phase of bipolar disorder. These delusions are described as “mood congruent.” That is, in patients with depression, the delusional content usually reflects self-deprecation, self-blame, hopelessness, or the conviction of ill health. A patient may complain that she has no blood or that her intestines are not working, for example; another patient may believe that he has caused a terrible wrong and deserves to be punished (a self-blaming delusion). Some patients become convinced that they are dying and that nothing can be done to help them when there is no physiologic evidence to support their concerns. Other common depressive delusions are the conviction that one has no insurance, no clothing, or no money when this is not true (delusion of poverty). Delusions congruent with mania are grandiose. Examples include the person’s belief that that he or she is infallible, can do impossible physical or intellectual activities, has skills and abilities that no other human being has, or is a special personage such as Jesus Christ. (See Depression and Other Mood Disorders.)
Patients with dementia experience both hallucinations and delusions. These are usually less complex than the delusions seen in schizophrenia or mood disorder. Common delusions in dementia are the belief that one’s belongings have been stolen or moved, or the conviction that one is being persecuted. Delusions that one’s spouse is unfaithful (delusions of infidelity) are also common. (See Dementia.)
Management of psychosis in dementia is particularly challenging, as the use of antipsychotic medication warrants careful consideration of risks and side effects. There has been recent attention to potential side effects of the newer antipsychotic medications in the class of atypical antipsychotics when used in patients with dementia. This group includes aripiprazole, olanzapine, risperidone, clozapine, quetiapine, and ziprasidone. One concern involves the risk of cerebrovascular adverse events (eg, stroke, transient ischemic attack) with risperidone, when such events were observed in clinical trials of risperidone in elderly patients with dementia-related psychosis. It is important to note that these clinical trials included patients with vascular dementia. The mechanism for the risk of cerebrovascular events has not yet been clarified. The observation of increased cerebrovascular events resulted in the addition of a warning to the product information. A class warning regarding atypical antipsychotics has already been applied concerning the risk of hyperglycemia in both younger and older patients with schizophrenia. The U.S. Food and Drug Administration has asked all manufacturers of atypical antipsychotic drugs to include a warning on the increased risk of developing hyperglycemia and diabetes. The mechanism for these adverse effects is unclear, although the fact that weight gain occurs with most of these medications may account for the increased rate of hyperglycemia.
Suspiciousness can be viewed as a personality trait, that is, an aspect of all human beings that varies among people in its degree of prominence. One epidemiologic study has found that suspiciousness becomes more common in older Americans and affects 4% of those aged 65 and over. It is distinguished from psychotic disorders by the understandable nature of the ideas (for example, excessive worry about safety) and the absence of other psychotic symptoms.
Between 10% and 13% of patients with significant visual impairment (bilateral acuity worse than 20/60) experience visual hallucinations. These can take the form of shapes such as diamonds or rectangles but more commonly consist of complex hallucinations such as small children, multiple animals, or a vivid scene such as one would see in a movie. This condition, first described more than 200 years ago, goes by the eponym Charles Bonnet syndrome. The criteria for this syndrome are as follows:
It has been suggested that this syndrome is a concomitant of the phantom limb syndrome caused by retinal lesions. However, visual hallucinations have also been reported in persons with field defects due to cortical lesions of the visual pathways.
The best treatment of the Charles Bonnet syndrome is information and support. Patients should be told that the hallucinations are a sign of eye disease, not mental illness. An occasional patient has partial insight or loses insight and becomes very distressed by this symptom. When this distress is significant or leads to dangerous behavior, a cautious trial of low doses of an atypical antipsychotic medication is occasionally beneficial.
Patients with Parkinson’s disease, stroke, and other brain disorders occasionally experience delusions and hallucinations without prominent cognitive impairment or other evidence of psychiatric disorder. Delirium due to a superimposed condition should be excluded. In patients with Parkinson’s disease, the symptoms may be secondary to prescribed dopaminergic agent, but some patients experience visual hallucinations prior to the onset of any pharmacotherapy. Education and support should be offered to all patients with these symptoms. If the patients experience significant emotional distress or the symptoms lead to dangerous or upsetting behavior, cautious use of an antipsychotic medication is appropriate. For patients with Parkinson’s disease and hallucinations, quetiapineOL 12.5 to 75 mg or olanzapineOL 2.5 to 5.0 mg daily may be beneficial. Some patients require clozapineOL 12.5 to 75.0 mg daily. However, clozapine requires a complete blood cell count once a week for 6 months and then biweekly thereafter because of the risk of granulocytopenia.
Dementia associated with Lewy bodies is increasingly recognized as an important cause of hallucinations in late life. The clinical scenario typically involves cognitive decline accompanied by motor features of parkinsonism. However, prominent visual hallucinations are a key part of the diagnosis. These hallucinations are often vivid and troubling. (See Dementia.)
Dementia associated with Lewy bodies presents a challenge similar to that of psychosis in Parkinson’s disease because the drugs in the class approved to treat psychosis, the antipsychotics, have been shown to worsen the parkinsonian symptoms. No trial data are available to guide drug choice, but there are case reports of significant improvement through the use of cholinesterase inhibitorsOL. If an antipsychotic medication must be used, then the treatment strategies outlined above are appropriate if there is careful attention to the risk of extrapyramidal side effects. Nonpharmacologic treatments include redirection, reassurance, and explanation.
■ Howard R, Rabins PV, Castle DJ, eds. Late Onset Schizophrenia. Petersfield, UK: Wrightson Biomedical Publishing Ltd.; 1999.
This is a compilation of presentations at an international consensus conference summarizing current thought on this condition. Chapter topics include epidemiology, clinical presentation, neuroimaging, and treatment. One chapter presents the view that this is not a unique syndrome.
■ Kertesz A, Munoz DG. Frontotemporal dementia. Med Clin North Am. 2002;86(3):501–518.
The clinical features of frontotemporal dementia are described. The under-recognition of this disorder and its pathologic and genetic features are discussed.
■ Marsh L. Neuropsychiatric aspects of Parkinson’s disease. Psychosomatics. 2000; 41(1):15–23.
This article nicely reviews the range of psychiatric symptoms seen in association with Parkinson’s disease, including hallucinations, delusions, anxiety symptoms, mood symptoms, and obsessive-compulsive phenomena. Treatment is discussed.
■ McKeith IG, Burn DJ, Ballard CG, et al. Dementia with Lewy bodies. Semin Clin Neuropsychiatry. 2003;8(1):46–57.
This review of dementia associated with Lewy bodies addresses the clinical characteristics and criteria for diagnosis as well as the literature on neuropathology and genetic implications.
■ Sachdev P, Brodaty H, Rose N, et al. Schizophrenia with onset after 50 years of age: 2: neurological, neuropsychological and MRI investigation. Br J Psychiatry. 1999; 175:416–421.
This article examines the correlates and risk factors of late-onset schizophrenia in a well-studied sample. It focuses on the question of whether structural brain damage is the primary progenitor of late-onset schizophrenia.
Peter V. Rabins, MD, MPH