The effect of citalopram adjunctive treatment added to atypical antipsychotic medications for cognitive performance in patients with schizophrenia

Association of antidepressant and benzodiazepine use, and anticholinergic burden with cognitive performance in schizophrenia

Schizophrenia is characterized by cognitive impairment affecting everyday functioning. Earlier research has hypothesized that antidepressants may associate with better cognitive functioning, but results are mixed. This study explored the association between antidepressant use and cognitive performance in terms of reaction time and visual learning in a clinical sample. In addition, we examined benzodiazepine use and anticholinergic burden. Study participants were drawn from the SUPER-Finland cohort, collected among patients with psychotic illnesses in 2016-2018 throughout Finland (n = 10,410). The analysis included adults with a schizophrenia diagnosis (F20) and results from a cognitive assessment (n = 3365). Information about medications and psychosocial factors were gathered through questionnaire and interview. Cognitive performance was assessed with the Cambridge Neuropsychological Test Automated Battery (CANTAB) with two subtests measuring reaction time and visual learning. Almost 36 % of participants used at least one antidepressant. The use of antidepressants in general was not associated with performance in the reaction time and visual learning tasks. However, the use of SNRI antidepressants was associated with a faster reaction time. Benzodiazepine use and a higher anticholinergic burden were associated with poorer performance in both tests. The results strengthen earlier findings that there is no association between antidepressant use in general and cognitive performance in schizophrenia. However, the association of SNRI medications with a faster reaction time warrants further research. Moreover, the results suggest that more attention should be paid to the anticholinergic burden of the medications used by patients with schizophrenia, as well as avoiding continuous benzodiazepine use.

Efficacy of different types of cognitive enhancers for patients with schizophrenia: a meta-analysis

Cognitive impairment is a core feature of schizophrenia, which is predictive for functional outcomes and is, therefore, a treatment target in itself. Yet, literature on efficacy of different pharmaco-therapeutic options is inconsistent. This quantitative review provides an overview of studies that investigated potential cognitive enhancers in schizophrenia. We included pharmacological agents, which target different neurotransmitter systems and evaluated their efficacy on overall cognitive functioning and seven separate cognitive domains. In total, 93 studies with 5630 patients were included. Cognitive enhancers, when combined across all different neurotransmitter systems, which act on a large number of different mechanisms, showed a significant (yet small) positive effect size of 0.10 (k = 51, p = 0.023; 95% CI = 0.01 to 0.18) on overall cognition. Cognitive enhancers were not superior to placebo for separate cognitive domains. When analyzing each neurotransmitter system separately, agents acting predominantly on the glutamatergic system showed a small significant effect on overall cognition (k = 29, Hedges’ g = 0.19, p = 0.01), as well as on working memory (k = 20, Hedges’ g = 0.13, p = 0.04). A sub-analysis of cholinesterase inhibitors (ChEI) showed a small effect on working memory (k = 6, Hedges’ g = 0.26, p = 0.03). Other sub-analyses were positively nonsignificant, which may partly be due to the low number of studies we could include per neurotransmitter system. Overall, this meta-analysis showed few favorable effects of cognitive enhancers for patients with schizophrenia, partly due to lack of power. There is a lack of studies involving agents acting on other than glutamatergic and cholinergic systems, especially of those targeting the dopaminergic system.

Efficacy and safety of antidepressant augmentation of continued antipsychotic treatment in patients with schizophrenia

OBJECTIVE

To evaluate the efficacy and safety of antidepressant augmentation of antipsychotics in schizophrenia.

METHODS

Systematic literature search (PubMed/MEDLINE/PsycINFO/Cochrane Library) from database inception until 10/10/2017 for randomized, double-blind, efficacy-focused trials comparing adjunctive antidepressants vs. placebo in schizophrenia.

RESULTS

In a random-effects meta-analysis (studies = 42, n = 1934, duration = 10.1 ± 8.1 weeks), antidepressant augmentation outperformed placebo regarding total symptom reduction [standardized mean difference (SMD) = -0.37, 95% confidence interval (CI) = -0.57 to -0.17, P < 0.001], driven by negative (SMD = -0.25, 95% CI = -0.44-0.06, P = 0.010), but not positive (P = 0.190) or general (P = 0.089) symptom reduction. Superiority regarding negative symptoms was confirmed in studies augmenting first-generation antipsychotics (FGAs) (SMD = -0.42, 95% CI = -0.77, -0.07, P = 0.019), but not second-generation antipsychotics (P = 0.144). Uniquely, superiority in total symptom reduction by NaSSAs (SMD = -0.71, 95% CI = -1.21, -0.20, P = 0.006) was not driven by negative (P = 0.438), but by positive symptom reduction (SMD = -0.43, 95% CI = -0.77, -0.09, P = 0.012). Antidepressants did not improve depressive symptoms more than placebo (P = 0.185). Except for more dry mouth [risk ratio (RR) = 1.57, 95% CI = 1.04-2.36, P = 0.03], antidepressant augmentation was not associated with more adverse events or all-cause/specific-cause discontinuation.

CONCLUSIONS

For schizophrenia patients on stable antipsychotic treatment, adjunctive antidepressants are effective for total and particularly negative symptom reduction. However, effects are small-to-medium, differ across antidepressants, and negative symptom improvement seems restricted to the augmentation of FGAs.

Randomized Controlled Trials of Add-On Antidepressants in Schizophrenia

BACKGROUND

Despite adequate treatment with antipsychotics, a substantial number of patients with schizophrenia demonstrate only suboptimal clinical outcome. To overcome this challenge, various psychopharmacological combination strategies have been used, including antidepressants added to antipsychotics.

METHODS

To analyze the efficacy of add-on antidepressants for the treatment of negative, positive, cognitive, depressive, and antipsychotic-induced extrapyramidal symptoms in schizophrenia, published randomized controlled trials assessing the efficacy of adjunctive antidepressants in schizophrenia were reviewed using the following parameters: baseline clinical characteristics and number of patients, their on-going antipsychotic treatment, dosage of the add-on antidepressants, duration of the trial, efficacy measures, and outcomes.

RESULTS

There were 36 randomized controlled trials reported in 41 journal publications (n=1582). The antidepressants used were the selective serotonin reuptake inhibitors, duloxetine, imipramine, mianserin, mirtazapine, nefazodone, reboxetin, trazodone, and bupropion. Mirtazapine and mianserin showed somewhat consistent efficacy for negative symptoms and both seemed to enhance neurocognition. Trazodone and nefazodone appeared to improve the antipsychotics-induced extrapyramidal symptoms. Imipramine and duloxetine tended to improve depressive symptoms. No clear evidence supporting selective serotonin reuptake inhibitors' efficacy on any clinical domain of schizophrenia was found. Add-on antidepressants did not worsen psychosis.

CONCLUSIONS

Despite a substantial number of randomized controlled trials, the overall efficacy of add-on antidepressants in schizophrenia remains uncertain mainly due to methodological issues. Some differences in efficacy on several schizophrenia domains seem, however, to exist and to vary by the antidepressant subgroups--plausibly due to differences in the mechanisms of action. Antidepressants may not worsen the course of psychosis. Better designed, larger, and longer randomized controlled trials are needed.

Treatment resistance and other complicating factors in the management of schizophrenia

Treatment resistance, along with its sibling partial response, remains a common phenomenon in schizophrenia, complicating the disability burden inherent in the disease. Antipsychotic medications are the mainstay of treatment, and treatment resistance has mainly been defined in terms of poor response to antipsychotic medication. At the same time, clozapine, the most effective antipsychotic, remains underutilized at the expense of exposing patients to polypharmacy. We review known causes of disability in schizophrenia, how they impact various areas of everyday functioning, and discuss potential treatment options including but not limited to pharmacological approaches aimed at maximizing treatment response and reducing treatment resistance.

Antidepressants for cognitive impairment in schizophrenia--a systematic review and meta-analysis

BACKGROUND

Cognitive impairment in schizophrenia is disabling, but current treatment options remain limited.

OBJECTIVE

To meta-analyze the efficacy and safety of adjunctive antidepressants for cognitive impairment in schizophrenia.

DATA SOURCES AND STUDY SELECTION

PubMed, MEDLINE, PsycINFO, and Cochrane Library databases were searched until 12/2013 for randomized controlled trials comparing antidepressant augmentation of antipsychotics with placebo regarding effects on cognitive functioning in schizophrenia.

DATA EXTRACTION

Two authors independently extracted data. Standardized mean differences (SMDs) were calculated for continuous outcomes and risk ratios for categorical outcomes. SMDs of individual cognitive tests were pooled on a study level within domains (primary outcome) and across domains. When results were heterogeneous, random instead of fixed effects models were used.

RESULTS

We meta-analyzed 11 studies (duration = 8.7 ± 3.7 weeks) including 568 patients (mean age = 39.5 ± 6.9 years, males = 67.2%, illness duration = 12.5 ± 8.0 years). Antidepressants included mirtazapine (4 studies; n = 126), citalopram (2 studies; n = 231), fluvoxamine (1 study; n = 47), duloxetine (1 study; n = 40), mianserin (1 study; n = 30), bupropion (1 study; n = 61), and reboxetine (1 study; n = 33). Statistically significant, but clinically negligible, advantages were found for pooled antidepressants compared to placebo in executive function (Hedges' g = 0.17, p = 0.02) and a composite cognition score (Hedges' g = 0.095, p = 0.012). Depression improved with serotonergic antidepressants (p = 0.0009) and selective serotonin reuptake inhibitors (p = 0.009), but not with pooled antidepressants (p = 0.39). Sedation was more common with pooled antidepressants (p = 0.04).

CONCLUSION

Adjunctive antidepressants do not demonstrate clinically significant effects on cognition in schizophrenia patients, however, larger studies, preferably in euthymic schizophrenia patients and using full neurocognitive batteries, are needed to confirm this finding.

Methods for treating cognitive deficits in schizophrenia

Studies from the molecular to clinical level suggest that cognitive dysfunction is central in characterizing schizophrenia. Accordingly, there have been increased efforts to search for effective treatments of these broad and debilitating cognitive deficits. Three general strategies for treating cognitive dysfunction in schizophrenia have emerged in the literature. The second-generation (atypical) antipsychotic medications have received much attention but their procognitive effects tend to be modest. Augmentation strategies, driven from basic science or translational research, have often been promising in small uncontrolled trials; however, few agents have fared well in rigorously designed trials. Behavioral interventions have demonstrated positive effects that generalize to other symptom domains and persist after the intervention, but tend to be costly and labor intensive. Thus, although there have been some exciting advances in treating cognitive dysfunction, the gains to date are modest and the search for treatment methods continues.

Pharmacological Interventions for the MATRICS Cognitive Domains in Schizophrenia: What's the Evidence?

Schizophrenia is a disabling, chronic psychiatric disorder with a prevalence rate of 0.5-1% in the general population. Symptoms include positive (e.g., delusions, hallucinations), negative (e.g., blunted affect, social withdrawal), as well as cognitive symptoms (e.g., memory and attention problems). Although 75-85% of patients with schizophrenia report cognitive impairments, the underlying neuropharmacological mechanisms are not well understood and currently no effective treatment is available for these impairments. This has led to the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative, which established seven cognitive domains that are fundamentally impaired in schizophrenia. These domains include verbal learning and memory, visual learning and memory, working memory, attention and vigilance, processing speed, reasoning and problem solving, and social cognition. Recently, a growing number of studies have been conducted trying to identify the underlying neuropharmacological mechanisms of cognitive impairments in schizophrenia patients. Specific cognitive impairments seem to arise from different underlying neuropharmacological mechanisms. However, most review articles describe cognition in general and an overview of the mechanisms involved in these seven separate cognitive domains is currently lacking. Therefore, we reviewed the underlying neuropharmacological mechanisms focusing on the domains as established by the MATRICS initiative which are considered most crucial in schizophrenia.

Drug-drug conditioning between citalopram and haloperidol or olanzapine in a conditioned avoidance response model: implications for polypharmacy in schizophrenia

Patients with schizophrenia often have anxiety and depression, and thus are treated with multiple psychotherapeutic medications. This practice of polypharmacy increases the possibility for drug-drug interactions. However, the pharmacological and behavioral mechanisms underlying drug-drug interactions in schizophrenia remain poorly understood. In the present study, we adopted a preclinical approach and examined a less known behavioral mechanism, drug-drug conditioning (DDC) between haloperidol (a typical antipsychotic) or olanzapine (atypical antipsychotic) and citalopram (a selective serotonin reuptake inhibitor). A rat two-way conditioned avoidance response paradigm was used to measure antipsychotic activity and determine how DDC may alter the antipsychotic efficacy in this model. Following acquisition of the avoidance response, rats were then randomly assigned to receive vehicle, citalopram (10.0 mg/kg, intraperitoneally), haloperidol (0.05 mg/kg, subcutaneously), olanzapine (1.0 mg/kg, subcutaneously), combined haloperidol with citalopram, or combined olanzapine with citalopram treatment for seven avoidance test sessions. In comparison with antipsychotic treatment alone, combined treatment with citalopram potentiated the antiavoidance effect of olanzapine or haloperidol (to a lesser extent) during the seven drug-test sessions. In addition, repeated pairing of citalopram with haloperidol or olanzapine caused citalopram to show a newly acquired avoidance-disruptive effect. This effect was context specific because citalopram paired with haloperidol or olanzapine outside the avoidance testing context (i.e. home cages) did not show such an effect. These findings indicate that concurrent antidepressant and antipsychotic treatments may engender a DDC process that follows the general Pavlovian associative conditioning principles. They also indicate that adjunctive citalopram treatment may enhance the antipsychotic efficacy of haloperidol and olanzapine in the treatment of schizophrenia.

Efficacy of antidepressants in treating the negative symptoms of chronic schizophrenia: meta-analysis

BACKGROUND

Treatment of negative symptoms in chronic schizophrenia continues to be a major clinical issue.

AIMS

To analyse the efficacy of add-on antidepressants for the treatment of negative symptoms of chronic schizophrenia.

METHOD

Systematic review and meta-analysis of randomised controlled trials comparing the effect of antidepressants and placebo on the negative symptoms of chronic schizophrenia, measured through standardised rating scales. Outcome was measured as standardised mean difference between end-of-trial and baseline scores of negative symptoms.

RESULTS

There were 23 trials from 22 publications (n = 819). The antidepressants involved were selective serotonin reuptake inhibitors, mirtazapine, reboxetine, mianserin, trazodone and ritanserin; trials on other antidepressants were not available. The overall standardised mean difference was moderate (-0.48) in favour of antidepressants and subgroup analysis revealed significant responses for fluoxetine, trazodone and ritanserin.

CONCLUSIONS

Antidepressants along with antipsychotics are more effective in treating the negative symptoms of schizophrenia than antipsychotics alone.

Effects of add-on mirtazapine on neurocognition in schizophrenia: a double-blind, randomized, placebo-controlled study

Mirtazapine added to antipsychotics appears to improve the clinical picture of schizophrenia, including both negative and positive symptoms. This study explored the effect of adjunctive mirtazapine on neurocognition in patients with schizophrenia who had shown an insufficient response to first-generation antipsychotics (FGAs). Thirty-seven schizophrenia patients, who were at least moderately ill despite their FGA treatment, received add-on mirtazapine (n=19) or placebo (n=18) in a 6-wk double-blind, randomized trial. Widely used neuropsychological tests were performed to explore visual-spatial functions, verbal and visual memory, executive functions, verbal fluency and general mental and psychomotor speed. The data were analysed on the modified intent-to-treat basis with last observation carried forward. False discovery rate was applied to correct for multiple testing. Mirtazapine outperformed placebo in the domains of visual-spatial ability and general mental speed/attentional control as assessed by, correspondingly, Block Design and Stroop dots. The difference in the degree of change (i.e. change while on mirtazapine minus that on placebo) was 18.6% (p=0.044) and 11.1% (p=0.044), respectively. Adjunctive mirtazapine might offer a safe, effective and cost-saving option as a neurocognitive enhancer for FGA-treated schizophrenia patients. Mirtazapine+FGA combinations may become especially useful in light of the currently increasing attention towards FGAs. Larger and longer studies that incorporate functional outcomes, as well as comparisons with second-generation antipsychotics are, however, still needed for more definite conclusions.

[Cognition and perception deficits in fibromyalgia and rheumatoid arthritis]

INTRODUCTION

Cognitive disturbance in patients with fibromyalgia and rheumatoid arthritis is today a topic of a great clinical interest, largely due to the fact that these persons often complain about cognitive problems.

OBJECTIVE

This study is aimed to assess the visuospatial memory, attention and perceptive capacities in chronic pain patients.

MATERIAL AND METHODS

Groups were constituted by fibromyalgia patients and rheumatoid arthritis patients, as well as a control group. All the subjects completed a battery of visual and spa-tial memory, speed of processing, working memory, attention, orientation and visuoperceptive abilities. A cognitive reserve measurement was obtained.

RESULTS

Results show that chronic pain patients displayed worse cognitive performance than controls. Moreover, arthritis patients execute poorly when compared to the group of fibromyalgia in tasks that demand visuoperceptive integration and visuomotor processing. Patients suffering fibromyalgia obtained worse punctuations than those with arthritis in spatial memory and spatial orientation tasks.

CONCLUSIONS

Both groups developed important cognitive deficits, which cannot be explained by the collateral effects of such pathologies, because cognitive profiles are not similar and appear from the beginning of the disease.

The effects of imipramine on P50 suppression, prepulse inhibition and habituation of the startle response in humans

Schizophrenic patients exhibit impairments in filtering of sensory information, as can be assessed by use of prepulse inhibition (PPI) of the acoustic startle response and P50 suppression paradigms. In the treatment of negative symptoms or depressive syndromes during the course of schizophrenia antidepressants are often combined with antipsychotic medication. However, antidepressants increase monoaminergic activity, which has been suggested to decrease sensory gating, although these presumptions are mostly based on results from animal studies. Currently, little is known about monoaminergic modulation of sensory filtering in humans, and the few reports that can be found in literature show discrepancies with animal studies. The current study was designed to study the effects of increased monoaminergic activity on sensory filtering and habituation of healthy volunteers. In a double-blind, placebo-controlled cross-over design, 20 healthy male volunteers received either placebo or a dose of 50 mg imipramine (a dual-acting antidepressant), after which they were tested in a P50 suppression paradigm, a PPI paradigm, and an habituation of the startle reflex paradigm. Imipramine significantly decreased PPI as well as P50 suppression. No significant differences between the two treatments were observed on habituation of the acoustic startle reflex. Since sensory filtering is usually already reduced in patients with schizophrenia, the current results call for caution in the widespread use of dual-acting antidepressants in the treatment of depressed or negative symptoms in these patients.

No effect of donepezil on neurocognition and social cognition in young persons with stable schizophrenia

INTRODUCTION

Cognitive dysfunction is common in schizophrenia and linked with psychosocial dysfunction. We examined the possible effect of a 16-week trial of donepezil on cognition in young persons with stable schizophrenia.

METHOD

Twenty-six outpatients who met criteria for age, duration of illness, clinical stability, and medications were randomly assigned to 16-week treatment with donepezil or placebo using a double blind design. At beginning and conclusion of the trial, participants completed standardised computerised assessment of neurocognition and social cognition. Symptomatology and functioning were assessed using standard rating scales for negative and positive symptoms, depression and mania, and quality of life.

RESULTS

No treatment effects were found on any cognitive functions or clinical symptoms in placebo or donepezil groups.

CONCLUSION

Similar to other studies using acetylcholinesterase inhibitors in more heterogeneous and symptomatic groups of patients with schizophrenia, donepezil does not appear to enhance cognitive abilities. Persistent cognitive impairment in schizophrenia with pervasive effects on psychosocial functioning and outcome, urge the search for agents that may offer improvement.

Cognitive deficits and functional outcome in schizophrenia

Cognitive dysfunction is a core feature of schizophrenia. Deficits are moderate to severe across several domains, including attention, working memory, verbal learning and memory, and executive functions. These deficits pre-date the onset of frank psychosis and are stable throughout the course of the illness in most patients. Over the past decade, the focus on these deficits has increased dramatically with the recognition that they are consistently the best predictor of functional outcomes across outcome domains and patient samples. Recent treatment studies, both pharmacological and behavioral, suggest that cognitive deficits are malleable. Other research calls into question the meaningfulness of cognitive change in schizophrenia. In this article, we review cognitive deficits in schizophrenia and focus on their treatment and relationship to functional outcome.

Antidepressants for people with both schizophrenia and depression

BACKGROUND

Depressive symptoms, often of substantial severity, are found in 50% of newly diagnosed suffers of schizophrenia and 33% of people with chronic schizophrenia who have relapsed. Depression is associated with dysphoria, disability, reduction of motivation to accomplish tasks and the activities of daily living, an increased duration of illness and more frequent relapses.

OBJECTIVES

To determine the clinical effects of antidepressant medication for the treatment of depression in people who also suffer with schizophrenia.

SEARCH STRATEGY

We undertook electronic searches of the Cochrane Schizophrenia Group's Register (October 2000), ClinPsych (1988-2000), The Cochrane Library (Issue 3, 2000), EMBASE (1980-2000) and MEDLINE (1966-2000). This was supplemented by citation searching, personal contact with authors and pharmaceutical companies.

SELECTION CRITERIA

All randomised clinical trials that compared antidepressant medication with placebo for people with schizophrenia or schizoaffective disorder who were also suffering from depression.

DATA COLLECTION AND ANALYSIS

Data were independently selected and extracted. For homogeneous dichotomous data the fixed effects risk difference (RD), the 95% confidence intervals (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, reviewers calculated weighted mean differences. Statistical tests for heterogeneity were also undertaken.

MAIN RESULTS

Eleven studies met the inclusion criteria. All were small, and randomised fewer than 30 people to each group. Most included people after the most acute phase of psychosis and investigated a wide range of antidepressants. The quality of reporting varied a great deal. For the outcome of 'no important clinical response' antidepressants were significantly better than placebo (n=209, 5 RCTs, summary risk difference fixed effects -0.26, 95% CI -0.39 to -0.13, NNT 4 95% CI 3 to 8). The depression score at the end of the trial, as assessed by the Hamilton Rating Scale (HAM-D), seemed to suggest that using antidepressants was beneficial, but this was only statistically significant when a fixed effects model was used (n=261, 6 RCTs, WMD fixed effects -2.2 95% CI -3.8 to -0.6; WMD random effects -2.1 95% CI -5.04 to 0.84). There was no evidence that antidepressant treatment led to a deterioration of psychotic symptoms in the included trials. Heterogeneous data on 'any adverse effect' are equivocal (n=110, 2 RCTs, RD fixed 0.11 CI -0.03 to 0.25, Chi square 7.5, df=1, p=0.0062). In one small study extrapyramidal adverse effects were reported less often by those allocated to antidepressant (n=52, 1 RCT, RD fixed -0.28 CI -0.5 to -0.04). Only about 10% of people left these studies by 12 weeks. There was no apparent difference between those allocated placebo and those given an antidepressant (n=426, 10 RCTs, RD fixed 0.04 CI -0.02 to 0.1).

REVIEWER'S CONCLUSIONS

Overall, the literature was of poor quality, and only a small number of trials made useful contributions. Though our results provide some evidence to indicate that antidepressants may be beneficial for people with depression and schizophrenia, the results, at best, are likely to overestimate the treatment effect, and, at worst, could merely reflect selective reporting of statistically significant results and publication bias. At present, there is no convincing evidence to support or refute the use of antidepressants in treating depression in people with schizophrenia. We need further well-designed, conducted and reported research to determine the best approach towards treating depression in people with schizophrenia.