Antidepressants in the treatment of psychosis with comorbid depression in Parkinson disease

Non-visual hallucinations in Parkinson's disease: a systematic review

BACKGROUND

Non-visual hallucinations in Parkinson's disease (PD) can be prevalent and distressing. Most existing research has however, focused on visual hallucinations as well as related risk factors. The current study thus conducted a systematic review to collate existing evidence on non-visual hallucinations in PD, focusing on their prevalence, phenomenology, and clinical-cognitive correlates.

METHODS

Ninety-one relevant studies were included from a systematic search across PsycINFO APA, PubMed, and Web of Science, for peer-reviewed publications in the English language, from 1970 to the present. These comprised a mix of case (30 studies; n = 56) and group design (62 studies; n = 7346) studies, divided into three somewhat overlapping collections to address our three research foci.

RESULTS

Prevalence estimates for hallucinations were: auditory 1.5-72.0%, olfactory 1.6-21.0%, somatic-tactile 0.4-22.5%, gustatory 1.0-15.0%, and sensed presence 0.9-73.3%. Phenomenological inquiries revealed descriptions of vivid, consuming events replete with elaborate detail, adversely affecting PD patients in different ways. Overt experiences of multisensory hallucinations were also highly variable (0.4-80%) but exceedingly common, reported by almost half of the 45 included prevalence studies. There was some evidence for modality-specific hallucination predictors, but this was largely tentative, pending robust replication.

CONCLUSIONS

Marked prevalence figures coupled with phenomenological descriptions implicating distress denote that non-visual and multisensory hallucinations in PD are of clinical significance. More direct research and clinical attention need to be devoted to the study and management of such hallucinatory experiences.

Psychosis in Parkinson Disease: A Review of Etiology, Phenomenology, and Management

Parkinson disease psychosis (PDP) is a common phenomenon in Parkinson disease (PD) patients treated with dopaminergic drugs, and is associated with high morbidity and mortality. It also correlates with depression and dementia, and can contribute to considerable caregiver stress and burnout. While symptoms can be relieved by decreasing doses or number of anti-PD medications, this may lead to an unacceptable worsening of motor function. When general medical or psychiatric conditions have been ruled out, and decreasing dopaminergic agents is not effective in treating psychosis, therapies include atypical antipsychotics, primarily clozapine and quetiapine. Of these, clozapine is effective but is associated with a poor side-effect profile and the necessity for frequent blood draws. Clinicians prefer quetiapine for its theoretically better safety profile, although there is no evidence for efficacy in treating psychosis. All atypical antipsychotics are associated with increased mortality in this patient population. Cholinesterase inhibitors can ameliorate psychosis symptoms. The serotonin 5-HT_2A receptor inverse agonist pimavanserin was recently approved by the US FDA for the treatment of PDP and may prove to be a more targeted therapy without the downsides of atypical antipsychotics.

Monoamine reuptake inhibitors in Parkinson's disease

The motor manifestations of Parkinson's disease (PD) are secondary to a dopamine deficiency in the striatum. However, the degenerative process in PD is not limited to the dopaminergic system and also affects serotonergic and noradrenergic neurons. Because they can increase monoamine levels throughout the brain, monoamine reuptake inhibitors (MAUIs) represent potential therapeutic agents in PD. However, they are seldom used in clinical practice other than as antidepressants and wake-promoting agents. This review article summarises all of the available literature on use of 50 MAUIs in PD. The compounds are divided according to their relative potency for each of the monoamine transporters. Despite wide discrepancy in the methodology of the studies reviewed, the following conclusions can be drawn: (1) selective serotonin transporter (SERT), selective noradrenaline transporter (NET), and dual SERT/NET inhibitors are effective against PD depression; (2) selective dopamine transporter (DAT) and dual DAT/NET inhibitors exert an anti-Parkinsonian effect when administered as monotherapy but do not enhance the anti-Parkinsonian actions of L-3,4-dihydroxyphenylalanine (L-DOPA); (3) dual DAT/SERT inhibitors might enhance the anti-Parkinsonian actions of L-DOPA without worsening dyskinesia; (4) triple DAT/NET/SERT inhibitors might exert an anti-Parkinsonian action as monotherapy and might enhance the anti-Parkinsonian effects of L-DOPA, though at the expense of worsening dyskinesia.

[Parkinson's disease and psychoses]

Psychotic symptoms are common in Parkinson's disease (PD) and are associated with increased disability, worsened quality of life, and poor long-term prognosis. In this article, clinical features, hypotheses on pathogenesis, and current treatment strategies for Parkinson's disease psychosis (PDP) are reviewed. According to epidemiological studies, the prevalence of PDP is between 20 to 40 %. Complex visual hallucinations are the most common psychotic symptoms and are present in 17-72 % of the patients. Other sensory disturbances encompass tactile hallucinations and minor hallucinatory phenomena, such as sense of presence and visual illusions. Hallucinations are often accompanied by delusions, whose most frequent themes are persecution and jealousy. The pathophysiology of PDP remains unclear. Different factors have been implicated, including Levo-dopa and dopaminergic medications, neurotransmitter imbalances, neuroanatomic alterations, abnormal visuospatial processes, and genetic predisposition. The first-line strategy in the treatment of persistent and problematic PDP is represented by reduction in anti-PD medications. Second-generation antipsychotics are the treatment of choice, with clozapine being demonstrated as the most effective and tolerable drug for PD patients.

Mirtazapine improves visual hallucinations in Parkinson's disease: a case report

Psychotic symptoms often occur as a complication in Parkinson's disease patients, and a set of criteria for Parkinson's disease with psychosis (PDPsy) has been established. Among these criteria, hallucinations are one of the specific symptoms, with visual hallucinations being the most common. While atypical antipsychotic agents are often used for the treatment of PDPsy, adverse effects, including extrapyramidal symptoms, often hinder its continuation or tolerance. There have been some reports and reviews indicating that antidepressants may be effective for PDPsy and other forms of dementia with psychosis. In this report, we present a patient with PDPsy who was treated with one of the new-generation antidepressants, mirtazapine. Mirtazapine improved the patient's refractory psychotic symptoms, especially her visual hallucinations, without worsening her motor symptoms.

New thoughts on thought disorders in Parkinson's disease: review of current research strategies and challenges

Psychosis is a frequent nonmotor complication in Parkinson's disease (PD), characterized by a broad phenomenology and likely due to a variety of intrinsic (i.e., PD-related) and extrinsic factors. Safe and effective therapies are greatly needed as PD psychosis contributes significantly to morbidity, mortality, nursing home placement, and quality of life. Novel research strategies focused on understanding the pharmacology and pathophysiology of PD psychosis, utilizing translational research including animal models, genetics, and neuroimaging, and even looking beyond the dopamine system may further therapeutic advances. This review discusses new research strategies regarding the neurobiology and treatment of PD psychosis and several associated challenges.

Parkinson's psychosis

OPINION STATEMENT

Psychosis is a leading reason for nursing home placement of patients with Parkinson's disease (PD). It may also be the single greatest stressor for caregivers of PD patients, it is generally persistent, and its presence markedly increases the risk of mortality. For these reasons, it is essential to recognize and appropriately treat psychosis in PD. Treatment of psychotic symptoms should be initiated after potential medical and environmental causes of delirium (eg, infection) have been eliminated or addressed. Initial pharmacologic changes should include limiting the patient's anti-PD medications to those that are necessary to preserve motor function (ie, eliminating adjunctive agents). Should that fail, an atypical antipsychotic agent is the treatment of choice. Clozapine is presently the gold standard, and quetiapine represents another option because of its ease of use and good tolerability profile. Emerging treatment options include the use of acetylcholinesterase inhibitors, antidepressants, and cognitive behavioral therapy. This article reviews what is currently known about treatment strategies in PD psychosis.

Neuropsychiatric symptoms in Parkinson's disease

Neuropsychiatric symptoms are common in Parkinson's disease, even at the earliest stages, and have important consequences for quality of life and daily functioning, are associated with increased carer burden and increased risk for nursing home admission. In addition to cognitive impairment, a wide range of neuropsychiatric symptoms have been reported. In this article, the epidemiology, clinical course, diagnosis, and management of some of the most common neuropsychiatric symptoms in PD are discussed: depression, anxiety, apathy, fatigue, and psychotic symptoms. Although much is known regarding the prevalence and course of these symptoms, the empirical evidence for how to manage these symptoms is limited at best. There is thus an urgent need for systematic studies for the pharmacological and non-pharmacological management of these symptoms.

Hallucinations in Parkinson disease

Patients with Parkinson disease (PD) can experience hallucinations (spontaneous aberrant perceptions) and illusions (misinterpretations of real perceptual stimuli). Of such phenomena, visual hallucinations (VHs) and illusions are the most frequently encountered, although auditory, olfactory and tactile hallucinations can also occur. In cross-sectional studies, VHs occur in approximately one-third of patients, but up to three-quarters of patients might develop VHs during a 20-year period. Hallucinations can have substantial psychosocial effects and, historically, were the main reason for placing patients in nursing homes. Concomitant or overlapping mechanisms are probably active during VHs, and these include the following: central dopaminergic overactivity and an imbalance with cholinergic neurotransmission; dysfunction of the visual pathways, including specific PD-associated retinopathy and functional alterations of the extrastriate visual pathways; alterations of brainstem sleep-wake and dream regulation; and impaired attentional focus. Possible treatments include patient-initiated coping strategies, a reduction of antiparkinson medications, atypical neuroleptics and, potentially, cholinesterase inhibitors. Evidence-based studies, however, only support the use of one atypical neuroleptic, clozapine, and only in patients without dementia. Better phenomenological discrimination, combined with neuroimaging tools, should refine therapeutic options and improve prognosis. The aim of this Review is to present epidemiological, phenomenological, pathophysiological and therapeutic aspects of hallucinations in PD.

Pathophysiology and treatment of psychosis in Parkinson's disease: a review

Psychotic symptoms in Parkinson's disease (PD) are relatively common and, in addition to creating a disturbance in patients' daily lives, have consistently been shown to be associated with poor outcome. Our understanding of the pathophysiology of psychosis in PD has expanded dramatically over the past 15 years, from an initial interpretation of symptoms as dopaminergic drug adverse effects to the current view of a complex interplay of extrinsic and disease-related factors.PD psychosis has unique clinical features, namely that it arises within a context of a clear sensorium and retained insight, there is relative prominence of visual hallucinations and progression occurs over time. PD psychosis tends to emerge later in the disease course, and disease duration represents one risk factor for its development. The use of anti-PD medications (particularly dopamine receptor agonists) has been the most widely identified risk factor for PD psychosis. Other risk factors discussed in the literature include older age, disease severity, sleep disturbance, cognitive impairment, dementia and/or depression.Recent efforts have aimed to explore the complex pathophysiology of PD psychosis, which is now known to involve an interaction between extrinsic, drug-related and intrinsic, disease-related components. The most important extrinsic factor is use of dopaminergic medication, which plays a prominent role in PD psychosis. Intrinsic factors include visual processing deficits (e.g. lower visual acuity, colour and contrast recognition deficits, ocular pathology and functional brain abnormalities identified amongst hallucinating PD patients); sleep dysregulation (e.g. sleep fragmentation and altered dream phenomena); neurochemical (dopamine, serotonin, acetylcholine, etc.) and structural abnormalities involving site-specific Lewy body deposition; and genetics (e.g. apolipoprotein E epsilon4 allele and tau H1H1 genotype). Preliminary reports have also shown a potential relationship between deep brain stimulation surgery and PD psychosis.When reduction in anti-PD medications to the lowest tolerated dose does not improve psychosis, further intervention may be warranted. Several atypical antipsychotic agents (i.e. clozapine, olanzapine) have been shown to be efficacious in reducing psychotic symptoms in PD; however, use of clozapine requires cumbersome monitoring and olanzapine leads to motor worsening. Studies of ziprasidone and aripiprazole are limited to open-label trials and case reports and are highly variable; however, it appears that while each may be effective in some patients, both are associated with adverse effects. While quetiapine has not been determined efficacious in two randomized controlled trials, it is a common first-line treatment for PD psychosis because of its tolerability, ease of use and demonstrated utility in numerous open-label reports. Cholinesterase inhibitors currently represent the most promising pharmacological alternative to antipsychotics. Tacrine is rarely tried because of hepatic toxicity, and controlled trials with donepezil have not shown significant reductions in psychotic symptoms, due perhaps to methodological limitations. However, results from an open-label study and a double-blind, placebo-controlled trial involving 188 hallucinating PD patients support the efficacy of rivastigmine. With regard to non-pharmacological interventions, case reports suggest that electroconvulsive therapy has the potential to reduce psychotic symptoms and may be considered in cases involving concurrent depression and/or medication-refractory psychosis. Limited case reports also suggest that specific antidepressants (i.e. clomipramine and citalopram) may improve psychosis in depressed patients. Finally, studies in the schizophrenia literature indicate that psychological approaches are effective in psychosis management but, to date, this strategy has been supported only qualitatively in PD, and further studies are warranted.

Intervening in the neuropsychiatric features of Parkinson's disease

Although Parkinson's disease is considered a movement disorder, it has a wide range and high prevalence of affective, psychotic, cognitive, behavioral and sleep-related features. To treat such features, agents including antidepressants, anxiolytics, antipsychotics and cognition-enhancing agents are commonly prescribed, although the targeted syndromes are often incompletely understood and controlled studies demonstrating a treatment's efficacy and tolerability in Parkinson's disease patients are often lacking. Nevertheless, the available information does suggest the outlines of management methods, pending expanded research to identify optimal strategies specific to Parkinson's disease.

Antidepressant use in treatment of psychosis with comorbid depression in Parkinson's disease

The authors report an improvement in delusions and hallucinations after antidepressant treatment (Clomipramine) in a parkinsonian patient with psychosis and comorbid depression. Their findings, which support a previous case treated with Citalopram, highlight the possible effectiveness of antidepressant therapy on psychotic symptoms in parkinsonian patients.

Use of concomitant medication with antipsychotic treatment in outpatients with schizophrenia: results from the European Schizophrenia Outpatients Health Outcomes (SOHO) study

Use of concomitant medications with antipsychotic agents in the treatment of schizophrenia is common but lacks a clear scientific rationale. We evaluated concomitant medication usage during the first 6 months of the prospective, observational, European Schizophrenia Outpatient Health Outcomes (SOHO) study, examining its frequency, variation according to type of antipsychotic drug used, and impact on treatment tolerability. We also determined factors that were associated with concomitant medication use. The use of concomitant medications differed greatly among the countries participating in the SOHO study. The presence of depressive symptoms and being female were associated with the use of concomitant antidepressants. Certain antipsychotics were associated with less use of concomitant medications: significantly fewer olanzapine-, quetiapine- and clozapine-treated patients used concomitant anticholinergics or anxiolytics/hypnotics. Patients using concomitant medications had an increased incidence of sexually related side effects and extrapyramidal side effects (EPS) at 6 months follow-up compared with patients not using concomitant medications. The results should be interpreted conservatively due to the observational design of SOHO.

Psychiatric aspects of Parkinson's disease

PURPOSE OF REVIEW

Recently, there has been much interest and rapid progress in understanding the neuropsychiatry of Parkinson's disease. This paper reviews the most important papers published during 2004 on dementia and cognitive impairment, depression and psychosis in Parkinson's disease.

RECENT FINDINGS

Many new studies of cognitive impairment and dementia in Parkinson's disease have been published during 2004. Cognitive impairment has been demonstrated even during the first 1-2 years after onset of disease. Whereas executive and attentional impairment is typical, learning deficits occur early in some patients. Both functional and structural imaging suggest that in addition to fronto-subcortical deficits, temporal and parietal changes occur early as well. In the first large placebo-controlled trial, the cholinesterase inhibitor rivastigmine improved cognition, daily functioning and psychiatric symptoms without worsening of parkinsonism. The frequency and characteristics of depression, anxiety and hallucinations have been explored in several studies. Unfortunately, there is still little scientific evidence available to guide the treatment of these important aspects of Parkinson's disease, and adequately designed clinical trials are needed. Although subthalamic stimulation, in addition to improvement of movement, is frequently associated with some affective and cognitive improvement, permanent and significant worsening may occur in some. Future studies should aim at identifying at-risk patients, as well as identifying the optimal pharmacological and stimulation treatments for individual patients.

SUMMARY

These findings provide a deeper understanding of the neurobiological substrate of cognitive impairment and dementia in Parkinson's disease, and provide new information regarding the assessment and management of dementia and other neuropsychiatric aspects of Parkinson's disease.