Cognitive enhancers.
In addition to their cognitive and functional benefit, there is evidence to suggest that acetyl cholinesterase inhibitors have shown some efficacy for NPSs in NCDs (
44). The benefit of cholinesterase inhibitors on the NPSs of dementia has been demonstrated among patients with AD, vaNCD, and Lewy body disease (
44–
47). Finkel (
45) reported that rivastigmine may be a well-tolerated treatment option for improving or preventing psychotic and nonpsychotic symptoms (such as apathy and agitation) associated with AD. The results from other studies showed that beneficial effects tend to be modest at best and, at times, lacking (
48). One study found no clear benefit from donepezil when compared with placebo on measures of NPSs in nursing home patients with AD (
49). Two studies evaluating rivastigmine among patients with AD who were institutionalized found no benefit for rivastigmine when compared with placebo or the second-generation antipsychotics (SGAs) quetiapine (
50) or risperidone in acute agitation (
51).
Some studies also have suggested that memantine may decrease emergent agitation of patients with AD. Memantine may also be effective for agitation and psychosis, and it is generally well-tolerated. Wilcock et al. (
52) conducted a pooled analysis of three large six-month randomized trials with patients who had moderate to severe AD. The study found that memantine is well-tolerated, is effective at managing NPSs, and improves general cognition and function (
52).
In summary, cognitive enhancers may have the additional benefit of preventing and reducing NPSs of patients with NCDs. Careful monitoring for side effects—such as gastrointestinal, bradycardia, and syncope—with cholinesterase inhibitors is important.
Antidepressants.
A large body of recent literature has examined the use of antidepressants for managing NPSs in NCDs. Selective serotonin reuptake inhibitors (SSRIs) in particular have been studied for depression, apathy, agitation, and psychosis in dementia. In what follows, we first review the studies that found benefits in antidepressants for management of NPSs in NCDs. Afterward, we review the studies that did not find such benefits.
Many studies have found that antidepressants, in particular citalopram and sertraline, are effective in treating agitation, and perhaps psychosis, of patients with AD. A systemic review by Sink et al. (
53) analyzed the double-blind, placebo-controlled trials (randomized controlled trials [RCTs]) published from 1966 to 2004, and it showed that among five studies examining antidepressants (sertraline, fluoxetine, citalopram, and trazodone), only citalopram was found to be effective in treating NPSs. Sertraline was also found to have significant benefit for treating depression in AD but not other symptoms (
53). Thompson et al. (
54) completed a meta-analysis of published, double-blind, placebo-controlled RTCs of antidepressants for treating depression in AD. They found a statistically significant effect in the proportion of patients who experienced a reduction and remission of depressive symptoms in favor of antidepressant therapy compared with placebo. The number needed to treat was five for both reduction in depressive symptoms and remission of depressive symptoms (
53). A more recent literature review found that SSRIs and trazodone are beneficial NPSs in NCDs, and it suggested that antidepressants are a safer option than antipsychotics for treating NPSs in NCDs (
37).
Seitz et al. (
55) performed a review of RCTs of antidepressants (SSRIs, tricyclic antidepressants, trazodone, and other antidepressants), compared with either placebo or comparator medications, for efficacy for and safety of patients (total of 692 patients) with NCDs experiencing agitation and psychosis. The authors concluded that sertraline and citalopram were associated with a reduction in symptoms of agitation when compared with placebo in two studies. Both SSRIs and trazodone appear to be tolerated reasonably well when compared with placebo, first-generation antipsychotics and SGAs (
55). The recent Citalopram for Agitation in Alzheimer Disease (CitAD) study was a randomized, placebo-controlled, double-blind study involving 186 patients with probable AD and clinically significant agitation from eight academic centers in the United States and Canada (
56). The patients received psychosocial intervention—in addition to either 10 mg/day of citalopram (with titration to 30 mg/day over three weeks; N=94) or placebo (N=92)—for nine weeks. Participants who received citalopram showed significant improvement on the Cohen-Mansfield Agitation Inventory (
57), total Neuropsychiatric Inventory (
58), and caregiver distress scores but not on the Neuropsychiatric Inventory Agitation subscale, activities of daily living, or in less use of rescue lorazepam. Worsening of cognition and QT interval prolongation were seen in the group receiving citalopram, although the cognitive decline was mild and clinically nonsignificant (1 point on the Mini-Mental State Exam) (
56,
59).
Despite these studies showing the benefits of using SSRIs in managing NPSs in NCDs, there are other studies that have questioned their efficacy for management of depression in dementia. A multicenter, placebo-controlled RCT of sertraline conducted with patients with AD and depression performed by Rosenberg et al. (
60) found increased side effect but no statistically significant benefit in the patients treated with sertraline compared with the group receiving placebo. Sepehry et al. (
61) focused specifically on comorbid depression of patients with AD in a meta-analysis of the efficacy of SSRIs, and they concluded that SSRIs do not seem to be efficacious in treating symptoms of depression in AD, and they also do not have any cognitive benefit. A multicenter, parallel-group, double-blind, placebo-controlled RCT of sertraline (target dose of 150 mg/day) and mirtazapine (target dose of 45 mg/day) for the treatment of depression in 326 patients with AD, with up to 39-week follow up, found that these antidepressants were ineffective at treating depression in AD; however, the study found increased adverse events in the patients treated with antidepressants compared with patients treated with placebos (
62).
In summary, there is evidence to suggest that SSRIs can be of benefit in managing depression and agitation in NCDs. Specifically, sertraline and citalopram appear to be tolerated with few adverse events. More recent studies have raised the need to reexamine the benefit of antidepressants for NPSs in NCDs. For improved evidence-based practice, more research is needed to better understand the effects of antidepressants and other medications for NPSs of patients with NCDs, looking at short- and long-term efficacy as well as the role of antidepressants in other etiologies of NCDs besides AD.
Antipsychotics.
The antipsychotic medications are not only the most widely prescribed class of drugs for the treatment of NPSs in NCDs but also the most controversial given issues of toxicity, increased mortality, cerebrovascular adverse effects, and cost. Until the mid-1990s, first-generation antipsychotics were the first-line pharmacological treatment for managing agitation and psychosis in dementia (
72). However, these medications have limited efficacy, at best, and carry increased risk of causing significant extrapyramidal side effects (EPSs), including Parkinsonism, tardive dyskinesia, dystonia, and heart-corrected QT interval prolongation. Today, atypical or SGAs are the most widely prescribed medication because they have fewer side effects and greater tolerability in the older adult population (
73). SGA side effects have prompted warnings from the Food and Drug Administration for increasing risk of mortality, stroke, and other cerebrovascular risks. Overall, SGAs are preferable to first-generation antipsychotics because of decreased risk of EPSs and possibly slightly lower mortality rate, but they are still not ideal in their risk-benefit ratio (
74).
The recently published American Psychiatric Association practice guidelines on the use of antipsychotics to treat agitation and psychosis of patients with dementia summarizes the evidence base and puts forth recommendations for clinical use of antipsychotics for psychosis and agitation in dementia (
75). The guidelines recommend against use of haloperidol as a first-line treatment for patients with dementia without evidence of delirium in nonemergency situations. The guidelines also suggest use of quantitative measures to develop a comprehensive treatment plan with individualized nonpharmacologic and pharmacologic interventions and to monitor a response to treatment (
75).
Kales et al. (
74) performed a retrospective cohort study on the safety of antipsychotics among 33,604 patients older than 65 years of age with NCDs with NPSs. The study revealed that although SGAs may improve some NPSs, their use is associated with significantly greater mortality, confirming the high level of risk with this treatment. Haloperidol was associated with the highest mortality risk, followed by the SGAs olanzapine and risperidone, valproic acid, and the SGA quetiapine (
74).
Several placebo-controlled RCTs show that SGAs, particularly olanzapine and risperidone, have a modest but significant advantage over placebo in the short-term treatment of agitation and psychosis in dementia (about 6–12 weeks) (
41,
76). The Clinical Antipsychotic Trials of Intervention Effectiveness—Alzheimer’s Disease study examined the safety and effectiveness of SGAs on associated psychosis and agitation in AD (
77). In this large, double-blind RCT, 421 outpatients either received olanzapine, quetiapine, risperidone, or placebo for 36 weeks. Although the trial failed to demonstrate differences in the primary outcome of effectiveness as measured by the time to discontinuation for any reason (either because of lack of effectiveness or adverse effect) of either medication versus placebo, secondary analyses indicated that olanzapine and risperidone were modestly efficacious in reducing NPSs. However, the medications did not improve cognition, functioning, quality of life, or care needs. Overall, the study concluded that the adverse effects of SGAs outweigh the modest advantages of the medication, although certain individuals who tolerate the medications may benefit from symptom reduction (
77).
Sink et al. (
53) reviewed 29 double-blind, placebo-controlled RCTs in a meta-analysis. First-generation antipsychotics had little efficacy and many severe side effects (including EPSs and sedation), whereas studies on SGAs, especially risperidone and olanzapine, found modest efficacy. Doses of 5–10 mg/day of olanzapine or 1.0 mg/day of risperidone appear to be at least modestly effective for treating NPSs of patients with AD or vaNCD (
53).
Several trials have focused specifically on the efficacy and safety of risperidone. De Deyn et al. (
72) analyzed three randomized, placebo-controlled, double-blind trials of patients with dementia treated with risperidone (1.0 mg/day) in a nursing home. The study found that risperidone is effective in treating agitation, psychosis, and aggression independent of NCD etiology, severity, and presence of psychosis. The investigators concluded that although side effects caused some patients to stop the medication, the drug generally had a favorable risk-benefit profile (
72). Similarly, Brodaty et al. (
78) performed a double-blind, placebo-controlled RCT to investigate efficacy and safety of risperidone in 345 patients with AD, vaNCD, or mixed AD and vascular disease. A low dose of .95 mg/day, over the course of 12 weeks, showed significant improvement in agitation and psychotic symptoms associated with NCDs. The study also found that risperidone did not cause cognitive decline but did come with relatively high cerebrovascular risks (
78).
Quetiapine treatment was effective in improving psychotic symptoms and agitation in several uncontrolled studies with patients who had NCDs (
76). A double-blind RCT that included 333 participants with NCDs, using Positive and Negative Syndrome Scale—Excitement Component scores (
79) as the primary outcome, found that 200 mg/day of quetiapine (but not 100 mg/day) was effective for treating agitation (
80). Another RCT with haloperidol, quetiapine, and placebo arms enrolled patients with AD (N=284) and found improvement of psychosis in all three groups, without statistically significant difference (
81). A smaller, double-blind RCT (N=46) of patients with AD did not find a statistically significant difference between placebo and quetiapine (median dose of 200 mg/day) (
82).
Recent studies have also examined other SGAs. Mintzer et al. (
83) conducted a placebo-controlled RCT of aripiprazole treatment of 487 patients with NCDs and psychosis. Aripiprazole, particularly at a 10 mg/day dose, was found to be effective especially for psychosis of patients with AD (
83). Similar results were reported by others for aripiprazole treatment of patients with AD (
84). However, a double-blind, flexible-dose RCT trial using patients with AD and psychotic symptoms who were institutionalized reported that aripiprazole did not confer specific benefits for the treatment of psychotic symptoms, but psychological and behavioral symptoms—including agitation, anxiety, and depression—were improved with aripiprazole and had a low risk of adverse effects (
85). A small RCT (N=129) comparing intramuscular injection of placebo and aripiprazole found that 10 or 15 mg i.m. aripiprazole administered in divided doses was safe and well tolerated for treatment of agitation associated with AD, vascular disease, or mixed dementia in long-term care (
86). Clozapine, the antipsychotic medication with the lowest risk of causing EPSs, has been studied among patients with NCDs complicated by Parkinsonian syndromes, including Lewy body dementia. In addition, clozapine can be effective for treatment-resistant agitation of patients with NCDs of multiple etiologies (
87,
88). Finally, ziprasidone has demonstrated efficacy in treating four separate inpatient cases of agitation and psychosis in dementia (
89).
Given that NPSs in NCDs fluctuate in severity, the optimal length of treatment with antipsychotics or other pharmacologic interventions is unknown (
90). Devanand et al. (
90) attempted to shed light on this important question by studying risk of relapse after discontinuation of risperidone treatment for patients with AD. In this study, 180 patients with AD and psychosis or agitation-aggression received open-label risperidone for 16 weeks, followed by randomization into three study arms: group 1 continued risperidone for 32 weeks; group 2 continued risperidone for 16 weeks and then switched to placebo for 16 weeks; group 3 switched to placebo for 32 weeks. Among patients with AD complicated by psychosis or agitation who had initially responded to risperidone therapy for 4–8 months, discontinuation of risperidone was associated with an increased risk of relapse (60% and 33% relapse comparing the first and the third groups, respectively, after 16 weeks) (
90). This study suggested that discontinuing risperidone in a patient with AD, complicated by psychosis or agitation, who had a sustained response for a period of months must be weighed against the increased risk of relapse and side effects.
Overall, SGAs are widely used and studied medications to treat and manage agitation and psychosis in dementia. There are also differing conclusions and opinions surrounding the risk-benefit profile of SGAs, especially given their substantial side effects. Individualized treatment plans, obtaining informed consent from the patient or health-care-proxy, selecting target symptoms for the interventions, starting medications at low-dose and titrating doses gradually, as well as close monitoring for response and side effect are recommended.