Psychosis in the Elderly

The differential diagnosis in an elderly patient such as Ms. A who presents with delusions, hallucinations, and behavioral disturbance can include psychosis related to delirium, general medical conditions, affective illness, dementia, schizophrenia or other primary psychotic disorders, and substance abuse or dependence.

From the initial interview and mental status examination, we can judge that there were three leading conditions that may have been contributing to Ms. A’s presentation of paranoid delusions, visual hallucinations, restlessness, and difficulty in being redirected: delirium; major depressive disorder, recurrent, severe with psychotic features; and dementia with delusions, depressed mood, and behavioral disturbance. Ms. A suffered from medical conditions that could predispose her to a delirium or a psychotic disorder due to a general medical condition. Because she presented with a clouded sensorium, which supported a diagnosis of delirium, a diagnosis of a psychotic disorder due to a general medical condition could not be fully supported at initial presentation.

There may be interactions among delirium, depression, and dementia. Elderly patients with dementia may have a lower threshold for delirium, and delirium has been associated with the development of dementia (1) . Similarly, depression may be a risk factor for developing dementia or be a prodrome of dementia (2) .

According to her son, Ms. A had a history of “strange thoughts” since early adulthood, raising the question of a possible primary psychotic disorder, such as schizophrenia, schizoaffective disorder, or delusional disorder, as part of her differential diagnosis. However, her premorbid social/occupational functioning and her course of illness did not support these diagnoses. It was judged that Ms. A’s “strange thoughts” were in fact unique overvalued ideas that were unlikely to have been truly psychotic in nature. Because she had not abused alcohol or other illicit substances in the past, and these were not accessible to her recently, substance abuse or dependence was not considered a likely cause of Ms. A’s psychotic symptoms. Alcohol and prescription drugs seem to be the main substances of abuse in the elderly, although illicit recreational drug abuse or dependence may become more prevalent with the aging of the baby boomers, who have an overall increased prevalence of illicit drug abuse that persists as this generation ages (3) .

Misuse or abuse of potentially addictive prescription drugs (benzodiazepines, opiates, and the like) and other drugs cited in the updated Beers criteria (4) for potentially inappropriate medication use in the elderly is of growing concern, as many elderly hospital admissions may be related to medications or toxic effects of medications. Inappropriate use of or withdrawal from centrally active prescriptions, over-the-counter and alternative medications, alcohol, and other psychoactive substances may trigger psychotic symptoms.

To determine or confirm what may be causing or interacting to cause the psychotic symptoms and to rule out additional etiologies, a thorough workup incorporating psychiatric, neurologic, and medical aspects of the history of the present illness, as well as blood, urine, brain, cardiac, and radiographic studies and other specialty assessments, was carried out.

The evaluation was prioritized according to clinical acuity and intervention impact, as indicated by the history and initial examination. Of the three leading conditions (delirium, depression with psychosis, and dementia), delirium was the most acute, emergent problem for which intervention would have great impact if a medically based reversible cause could be identified and addressed in a timely fashion. As described below, when Ms. A’s delirium cleared, signs and symptoms of her depressive illness with psychosis became more prominent. Once her depression with psychosis was stabilized, her underlying dementia was more clearly apparent and interventions related to it were considered.

Delirium has been reported to be the third most common cause of psychosis in elderly outpatients, associated with 12.2% of diagnoses (8) . Delirium-related psychosis is characterized by thought disturbance with themes that tend to be from the current environment and situations, with poverty of thinking and irrationality, and with hallucinations (often visual) (9, 10) .

Ms. A was worked up and treated for conditions that can cause delirium, such as inappropriate drug use, withdrawal from drugs, infection, urinary retention, constipation, physiologic abnormalities, cardiovascular problems, intracranial strokes, seizures or hemorrhages, and sensory deprivation.

The medications that Ms. A was taking at the time of admission were reviewed. Because of modest efficacy and minimal effectiveness of most psychotropic agents in managing behavioral disturbances, multiple drugs are often used in the hope that there will be some combined efficacy. This all too often has the unintended consequence of exacerbating behavioral difficulties. For Ms. A, it was noted that sedative, antipsychotic, anticonvulsant, and antidepressant medications (lorazepam, quetiapine, divalproex, and sertraline) had been prescribed in relatively large doses for agitation, anxiety, delusions, hallucinations, mood instability, and depression. At high doses and in combination, they were judged to be adding to her acute confusional state. Thus, a psychotropic “drug holiday” was initiated. Psychotropic medications were tapered down in dose and then discontinued, despite Ms. A’s history of major depression with psychosis and Alzheimer’s type dementia with behavioral disturbance. Ms. A would then be monitored for emergent psychiatric signs and symptoms as her delirium cleared, and psychotropic medications would be reintroduced sequentially if clinically appropriate as her delirium resolved.

Ms. A also was found to have an E. coli urinary tract infection and constipation, both of which may contribute to delirium, especially in elderly persons with dementia. To treat the infection, Ms. A received antibiotics according to the results of the urine culture antibiotic sensitivities. Fluid intake was encouraged, and she was started on a probiotic. For constipation, a bowel regimen with a high-fiber diet, increased oral fluids, a bulk former, a stool softener, and an intestinal stimulant was initiated.

Her levels of free T ₄ and total T ₃ were low, and the thyroid-stimulating hormone level was elevated, suggesting that Ms. A had not been taking adequate doses of her thyroid medication. A hypothyroid state can cause a delirium and resemble a dementia. Endocrinologic consultation was obtained and levothyroxine dosages were readjusted.

In her more lucid moments, Ms. A conveyed that she had pain, which can contribute to delirium. She gestured on separate occasions to her stomach. In the light of such cardiac risk factors as chronic atrial fibrillation, hypertension, and hypercholesterolemia, aspirin had been prescribed to prevent ministrokes. After reviewing Ms. A’s clinical condition and medications further, it was judged that the aspirin might be causing her abdominal discomfort, despite the use of medication for gastroesophageal reflux disease. In her current situation, it was judged that the risks outweighed the benefits of continuing on aspirin therapy, and the aspirin was discontinued. Within a few days, her complaints of abdominal distress declined. Reducing pharmacologic treatments when appropriate may be more helpful than adding more medication.

Ms. A’s sensorium continued to clear, and she had fewer episodes of psychosis and purposeless hyperactivity. When such episodes occurred, they were intermittent and consisted of brief periods of delusions with pacing, during which times she was redirectable. She was more responsive to interactive and milieu interventions, occupational therapy, and physical therapy.

Major depression has been reported to be the second most common diagnosis in elderly outpatients, accounting for most psychosis in this population (8) . In contrast to psychosis associated with delirium, depression-related psychosis in the elderly is often characterized by themes of somatic troubles, persecution, guilt, and poor self-esteem (11) .

Psychosis is an important aspect of dementia and poses a major health concern for the elderly. Dementia has been reported to be the most common diagnosis accounting for psychosis in elderly outpatients (8) . Estimates for the prevalence of delusions in dementia have ranged from 9% to 63% (median, 36%), and for hallucinations, 4% to 41% (median, 18%) (16) . The treatment prevalence of delusions and hallucinations in dementia has been reported to be 25%, with hallucinations remitting over a few months and delusions being more persistent (17) . Often, delusions of patients with Alzheimer’s type dementia are simple, probably because of cognitive impairments that preclude the elaboration of complex ideas. They are often of a paranoid nature, where patients believe that items are being stolen from them, that they are being abandoned, or that their spouse and children are being disloyal to them.

Currently, there are two classes of cognitive enhancer drugs available by prescription: cholinesterase inhibitors (tacrine, donepezil, rivastigmine, and galantamine) and the N -methyl- d -aspartate receptor antagonist memantine. Cognitive and noncognitive benefits from these medications may be subtle, may occur slowly, and may be difficult to evaluate consistently in a clinical setting. Their clinical effectiveness may be more apparent when these drugs are discontinued, such as due to a lack of perceived positive effect or because of side effects. In these situations, some patients suffer a clinically significant loss of clarity, behavioral stability, and function, which may be restored when the cognitive enhancers are restarted in a timely fashion. For Ms. A, memantine, which is indicated for treating moderate to severe Alzheimer’s type dementia, was judged to have a more favorable risk-benefit profile than the cholinesterase inhibitors. Ms. A had atrial fibrillation and was on two atrioventricular nodal blocking medications (digoxin and the beta-blocker metoprolol, which had been started after a trial with a calcium channel blocker had failed to treat the arrhythmia). Bradycardia and heart block may be caused by acetylcholinesterase inhibitors and, if severe enough, might increase Ms. A’s risk of sudden death. Ms. A also had a history of frequent falls, and increased cardiovascular compromise could increase her vulnerability to falling. In addition, Ms. A had gastroesophageal reflux disease. The cholinesterase inhibitors are known to increase gastric acid secretion, which might cause Ms. A more discomfort, despite her taking medication for gastroesophageal reflux disease. In contrast to the cholinesterase inhibitors, memantine, with its low incidence of relatively minor side effects, seemed to be a better choice. However, the possible side effects of increased confusion and hallucinations with memantine were of concern, as Ms. A had been very confused and was hallucinating when she was first hospitalized. Although not entirely free of all psychotic symptoms, Ms. A had finally reached a point where she was clearer and had some quality of life, as she was not in physical pain and could enjoy visits from her son. Given the severe consequences of the dementia, it was important to provide Ms. A with the opportunity for as much treatment and support as clinically appropriate and beneficial. After considering Ms. A’s clinical history and progress and the advantages and disadvantages of treatment with cognitive enhancers, Ms. A’s son and the treatment team decided that the potential risks of treatment with cognitive enhancers outweighed the potential benefits. Thus, Ms. A was discharged from the hospital to a skilled nursing facility in stable condition without starting a trial of cognitive enhancer therapy.