Verbal learning deficits associated with increased anticholinergic burden are attenuated with targeted cognitive training in treatment refractory schizophrenia patients

Pharmacologic Augmentation of Computerized Auditory Training in Chronic Psychosis: Preliminary Findings From a Single-Site, Double-Blind Study

BACKGROUND

Computerized auditory training (AT) modestly improves symptoms, cognition, and functioning in schizophrenia. We assessed whether d-amphetamine (AMPH) or memantine (MEM) can enhance gains from 30-h of AT.

METHODS

Antipsychotic-medicated individuals with chronic psychosis (n = 68; mean age 47.03y; M:F = 39:29) completed up to 30 AT sessions (2-3/week; n = 50 completed 30 sessions) in 3 groups: "AMPH group" (AMPH (5 mg po) 1-h before each AT session); "MEM group" (titrated to 10 mg MEM bid and maintained that dose throughout training); "PBO group" (PBO dosed identically to either AMPH or MEM). Primary (PANSS total, MCCB Composite, WHODAS) and secondary (PANSS positive, PANSS negative, YMRS, PHQ-9, PSYRATS) outcome measures were acquired at baseline, after 10, 20, and 30 AT sessions, and 12 weeks post-training. Pill identity (active/PBO) was blind to subjects and staff.

RESULTS

Marginally significant between-group gains for AMPH vs PBO were detected for one of three primary outcomes (WHODAS, P =.050; but not PANSS total or MCCB Composite), and for 3 of 5 secondary clinical outcomes (PANSS positive, YMRS, PSYRATS, P's≤.027-.049). Within-subject gains over time were detected for primary and secondary clinical measures for AMPH (P's≤.014-.004) and MEM (P's≤.02-.001) groups; some of these would not survive conservative correction for multiple comparisons. No measures detected symptom worsening; treatment satisfaction exceeded subjects' expectations.

CONCLUSIONS

Results are mixed; drug-associated gains in several measures vs PBO suggest that these regimens may augment AT-induced functional and clinical improvement in psychosis patients, independent of changes in neurocognition. Assessment in larger samples seems warranted.

Anticholinergic Burden and Cognitive Function in Psychosis: A Systematic Review and Meta-Analysis

OBJECTIVE

The authors synthesized evidence from studies quantifying the relationship between anticholinergic medication and cognitive function in psychosis, and additionally explored studies that investigated whether reducing anticholinergic medications affects cognitive function in individuals with psychosis.

METHODS

A database search was conducted in MEDLINE, Embase, and PsycINFO, from database inception to October 2023, for studies reporting objective cognitive assessment and quantification of anticholinergic burden using clinical scales, serological anticholinergic activity, or tapering of anticholinergic medications. Analyses were carried out in R using the metafor package. Random-effects meta-analysis models were employed, along with assessment of heterogeneity, study quality, and meta-regressions (age, sex, and antipsychotic dosage in chlorpromazine equivalents).

RESULTS

Of 1,337 citations retrieved, 40 met inclusion criteria, comprising 25 anticholinergic burden studies (4,620 patients), six serological anticholinergic activity studies (382 patients), and nine tapering studies (186 patients). A negative correlation was identified between anticholinergic burden and global cognition (r=-0.37, 95% CI=-0.48, -0.25), verbal learning (r=-0.28, 95% CI=-0.36, -0.21), visual learning (r=-0.17, 95% CI=-0.28, -0.06), working memory (r=-0.22, 95% CI=-0.29, -0.14), processing speed (r=-0.24, 95% CI=-0.35, -0.13), attention (r=-0.19, 95% CI=-0.29, -0.08), executive functions (r=-0.17, 95% CI=-0.27, -0.06), and social cognition (r=-0.12, 95% CI=-0.19, -0.05), and between serological anticholinergic activity and verbal learning (r=-0.26, 95% CI=-0.38, -0.14), working memory (r=-0.19, 95% CI=-0.35, -0.03), and executive functions (r=-0.16, 95% CI=-0.27, -0.04). Finally, tapering off anticholinergic medication improved the scores in verbal learning (d=0.77, 95% CI=0.44, 1.1), working memory (d=0.94, 95% CI=0.63, 1.26), and executive functions (d=0.44, 95% CI=0.26, 0.62).

CONCLUSIONS

Anticholinergic burden is associated with the cognitive impairments observed in psychosis. From a clinical perspective, tapering off anticholinergic medication in patients with psychosis may improve cognition. However, randomized clinical trials are needed for an unbiased quantification of benefit.

A qualitative analysis of participant experience during an EEG-linked auditory targeted cognitive training exercise: Implications for implementation and protocol optimization

Auditory-based targeted cognitive training (ATCT) is an emerging adaptive neuroplasticity-based intervention. Previous studies have shown that electroencephalographic (EEG) biomarkers of auditory information processing assessed at the start of ATCT have predicted cognitive, clinical, and functional gains from a full 30-40 hour ATCT program, but participant attitudes related to coupling EEG to ATCT are not well-known. This study assessed stakeholder feedback related to EEG biomarker collection as part of ATCT to optimize future EEG-informed ATCT studies. Semi-structured interviews assessed attitudes of ATCT-naïve participants (n=50) living with a range of psychiatric disorders and cognitive function who underwent EEG assessment associated with a 1 hour ATCT exercise. A deductive approach was used to code the data and an iterative approach was employed to identify key emerging themes. Interview data yielded 62 unique themes related to EEG biomarker collection and ATCT. Qualitative analysis identified positive and negative elements of participants' experience of EEG-informed ATCT as well as ways to streamline the EEG experience. Results suggest EEG-informed ATCT studies may be optimized using actionable improvements to current protocols leveraged from themes identified.

Conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia

Cognitive impairment represents one of the core features of schizophrenia, involves both neurocognition and social cognition domains, and has a significant negative impact on real-world functioning. The present review provides a framework for the conceptualization and characterization of "primary" and "secondary" cognitive impairment in schizophrenia. In this conceptualization, primary cognitive impairment can be defined as a consequence of the neurobiological alterations that underlie psychopathological manifestations of the disorder, while secondary cognitive impairment can be defined as the results of a source issue that has a negative impact on cognitive performance. Sources of secondary cognitive impairment are frequent in people with schizophrenia and include several different factors, such as positive and negative symptoms, depressive symptoms, autistic symptoms, pharmacotherapy, substance abuse, metabolic syndrome, social deprivation, and sleep disorders. It can be hypothesized that secondary cognitive impairment may be improved by effectively resolving the source issue, while primary cognitive impairment may benefit from dedicated treatment. Further research is required to confirm this hypothesis, to better characterize the distinction between primary and secondary cognitive impairment in a clinical and in a neurobiological perspective, and to evaluate the impact of systematically assessing and treating secondary cognitive impairment.

Comparative analysis of anticholinergic burden scales to explain iatrogenic cognitive impairment in schizophrenia: results from the multicenter FACE-SZ cohort

Aim

The anticholinergic properties of medications are associated with poorer cognitive performance in schizophrenia. Numerous scales have been developed to assess anticholinergic burden and yet, there is no consensus indicating which anticholinergic burden scale is more relevant for patients with schizophrenia. We aimed to identify valid scales for estimating the risk of iatrogenic cognitive impairment in schizophrenia.

Methods

We identified 27 scales in a literature review. The responses to neuropsychological tests of 839 individuals with schizophrenia or schizoaffective disorder in the FACE-SZ database were collected between 2010 and 2021. We estimated the association between objective global cognitive performance and the 27 scales, the number of psychotropic drugs, and chlorpromazine and lorazepam equivalents in bivariable regressions in a cross-sectional design. We then adjusted the bivariable models with covariates: the predictors significantly associated with cognitive performance in multiple linear regressions were considered to have good concurrent validity to assess cognitive performance.

Results

Eight scales, the number of psychotropic drugs, and drug equivalents were significantly associated with cognitive impairment. The number of psychotropic drugs, the most convenient predictor to compute, was associated with worse executive function (Standardized β = -0.12, p = .004) and reasoning (Standardized β = -0.08, p = .037).

Conclusion

Anticholinergic burden, the number of psychotropic drugs, and drug equivalents were weakly associated with cognition, thus suggesting that cognitive impairment in schizophrenia and schizoaffective disorder is explained by factors other than medication. The number of psychotropic drugs was the most parsimonious method to assess the risk of iatrogenic cognitive impairment.

Pharmacological Treatment of Cognitive Impairment Associated With Schizophrenia: State of the Art and Future Perspectives

Cognitive Impairment Associated with Schizophrenia (CIAS) represents one of the core dimensions of Schizophrenia Spectrum Disorders (SSD), with an important negative impact on real-world functional outcomes of people living with SSD. Treatment of CIAS represents a therapeutic goal of considerable importance, and while cognition-oriented evidence-based psychosocial interventions are available, effective pharmacological treatment could represent a game-changer in the lives of people with SSD. The present critical review reports and discusses the evidence regarding the effects of several pharmacological agents that are available in clinical practice or are under study, commenting on both current and future perspectives of CIAS treatment. In particular, the effects on CIAS of antipsychotic medications, anticholinergic medications, benzodiazepines, which are currently commonly used in the treatment of SSD, and of iclepertin, d-serine, luvadaxistat, xanomeline-trospium, ulotaront, anti-inflammatory molecules, and oxytocin, which are undergoing regulatory trials or can be considered as experimental agents, will be reported and discussed. Currently, available pharmacological agents do not appear to provide substantial benefits on CIAS, but accurate management of antipsychotic medications and avoiding treatments that can further exacerbate CIAS represent important strategies. Some molecules that are currently being investigated in Phase 2 and Phase 3 trials have provided very promising preliminary results, but more information is currently required to assess their effectiveness in real-world contexts and to provide clear recommendations regarding their use in clinical practice. The results of ongoing and future studies will reveal whether any of these molecules represents the awaited pharmacological game-changer in the treatment of CIAS.

Medication impact on oral health in schizophrenia

BACKGROUND

Patients with schizophrenia constitute a particularly vulnerable group for oral diseases. Among the different factors involved, we aimed to examine the evidence of how drugs could contribute to the poorer oral health of this population.

MATERIAL AND METHODS

An overview of the potential impact of medication on dental/oral health among people with schizophrenia was proposed focusing on selected literature.

RESULTS

Studies show a higher dental caries and degree of periodontal diseases in this population and point to drug-induced xerostomia as an important risk factor for oral health deterioration. The risk of dry mouth depends on not only antipsychotics, but also drugs with anticholinergic activity. We hypothesize that antipsychotic induced glycaemic alterations might contribute to reduced oral health, and that the antimicrobial activity of certain antipsychotics could have an impact on oral microbiota affecting oral condition. Pharmacovigilance data show that involuntary movements are caused by typical and some atypical antipsychotics. Dry mouth is most frequently reported for quetiapine and olanzapine, while clozapine is more frequently associated with sialorrhea.

CONCLUSIONS

Literature clearly shows higher caries and periodontal disease in schizophrenic patients. However, overall, there is scarce literature about the potential influence of drugs in these disorders. Health professionals should be aware of this issue in order to implement adequate preventive measures in this vulnerable population.

Effects of Anticholinergic Burden on Verbal Memory Performance in First-Episode Psychosis

OBJECTIVES

Antipsychotics are widely used to treat first-episode psychosis but may have an anticholinergic burden, that is, a cumulative effect of medications that block the cholinergic system. Studies suggest that a high anticholinergic burden negatively affects memory in psychosis, where cognitive deficits, particularly those in verbal memory, are a core feature of the disease. The present study sought to replicate this in a large cohort of well-characterized first-episode psychosis patients. We expected that patients in the highest anticholinergic burden group would exhibit the poorest verbal memory compared to those with low anticholinergic burden and healthy controls at baseline (3 months following admission). We further hypothesized that over time, at month 12, patients' verbal memory performance would improve but would remain inferior to controls.

METHODS

Patients (n  =  311; low anticholinergic burden [n  =  241] and high anticholinergic burden [n  =  70], defined by a Drug Burden Index cut-off of 1) and healthy controls (n  =  128) completed a clinical and neurocognitive battery including parts of the Wechsler Memory Scale at months 3 and 12.

RESULTS

Cross-sectionally, using an analysis of variance, patients in the highest anticholinergic burden group had the poorest performance in verbal memory when compared to the other groups at month 3, F(2,430)  =  52.33, P < 0.001. Longitudinally, using a Generalized Estimating Equation model, the verbal memory performance of all groups improved over time. However, patients' performance overall remained poorer than the controls.

CONCLUSION

These findings highlight the importance of considering the anticholinergic burden when prescribing medications in the early stages of the disease.

Effect of anticholinergic burden on brain activity during Working Memory and real-world functioning in patients with schizophrenia

Cognitive impairment has been associated with poor real-world functioning in patients with Schizophrenia. Previous studies have shown that pharmacological treatment with anticholinergic properties may contribute to cognitive impairment in Schizophrenia. We investigated the effect of the anticholinergic burden (ACB) on brain activity, cognition, and real-world functioning in Schizophrenia. We hypothesized that greater ACB would be associated with altered brain activity along with poorer cognitive performance and lower real-world functioning. A sample of 100 patients with a diagnosis of schizophrenia or schizoaffective disorder was recruited in the naturalistic multicenter study of the Italian Network for Research on Psychoses (NIRP) across 7 centres. For each participant, ACB was evaluated using the Anticholinergic Cognitive Burden scale. The association of ACB with brain function was assessed using BOLD fMRI during the N-Back Working Memory (WM) task in a nested cohort (N = 31). Real-world functioning was assessed using the Specific Level of Functioning (SLOF) scale. Patients with high ACB scores (≥3) showed lower brain activity in the WM frontoparietal network (TFCE corrected alpha <0.05) and poorer cognitive performance (p = 0.05) than patients with low ACB scores (<3). Both effects were unaffected by demographic characteristics, clinical severity, and antipsychotic dosage. Moreover, patients with high ACB showed poorer real-world functioning than patients with lower ACB (p = 0.03). Our results suggest that ACB in Schizophrenia is associated with impaired WM and abnormal underlying brain function along with reduced real-world functioning. Clinical practice should consider the potential adverse cognitive effects of ACB in the treatment decision-making process.

Mismatch negativity predicts initial auditory-based targeted cognitive training performance in a heterogeneous population across psychiatric disorders

Auditory-based targeted cognitive training (ATCT) programs are emerging pro-cognitive therapeutic interventions which aim to improve auditory processing to attenuate cognitive impairment in a "bottom up" manner. Biomarkers of early auditory information processing (EAIP) like mismatch negativity (MMN) and P3a have been used successfully to predict gains from a full 40 h course of ATCT in schizophrenia (SZ). Here we investigated the ability of EAIP biomarkers to predict ATCT performance in a group of subjects (n = 26) across SZ, MDD, PTSD and GAD diagnoses. Cognition was assessed via the MATRICS Consensus Cognitive Battery (MCCB) and MMN/P3a were collected prior to completing 1 h of "Sound Sweeps," a representative ATCT exercise. Baseline and final performance over the first two levels of cognitive training served as the primary dependent variables. Groups had similar MMN, but the SZ group had attenuated P3a. MMN and MCCB cognitive domain t-scores, but not P3a, were strongly correlated with most ATCT performance measures, and explained up to 61% of variance in ATCT performance. Diagnosis was not a significant predictor for ATCT performance. These data suggest that MMN can predict ATCT performance in heterogeneous neuropsychiatric populations and should be considered in ATCT studies across diagnostically diverse cohorts.

Normal-range verbal memory in the first-episode of psychosis: Clinical and functional outcomes across 24 months and impact of estimated verbal memory decrement

Verbal memory (VM) dysfunction is prevalent in first-episode psychosis (FEP) and has major impacts on long-term functional and clinical outcomes. Nevertheless, a substantial proportion of FEP patients have VM performance in the norm, called normal-range (NR) VM, and only a few studies have explored its relation to outcomes. Moreover, probable decrements between estimated premorbid and current cognitive performance could confuse the relationship between VM and clinical or functional outcomes in FEP patients. These potential interactions have not yet been considered in FEP, thus, we examined 1) the longitudinal relationship between VM performance (NR vs. below NR (BNR)) in FEP and clinical and functional outcomes over 24 months following admission to treatment, and 2) compared the clinical and functional status of NR patients with and without cognitive decrement at baseline and 12 months. A total of 271 patients (BNR = 114, NR = 157; 81 out of 105 NR with decrement) completed measures of psychosocial functioning and clinical symptoms at baseline, month 12, and month 24. Generalized Estimating Equations and unpaired t-tests were used to address the first and second aim, respectively. NR demonstrated better functioning and fewer negative symptoms when compared to BNR. Interestingly, NR patients with decrement reported significantly more negative symptoms at baseline compared to their counterparts without decrement. These findings document that a large proportion (57.9 %) of FEP patients have NR VM that appear to be functionally advantageous but that NR VM is nuanced by the presence or absence of a potential decrement early in the developmental course of the disorder.

European Psychiatric Association guidance on treatment of cognitive impairment in schizophrenia

Background

Although cognitive impairment is a core symptom of schizophrenia related to poorer outcomes in different functional domains, it still remains a major therapeutic challenge. To date, no comprehensive treatment guidelines for cognitive impairment in schizophrenia are implemented.

Methods

The aim of the present guidance paper is to provide a comprehensive meta-review of the current available evidence-based treatments for cognitive impairment in schizophrenia. The guidance is structured into three sections: pharmacological treatment, psychosocial interventions, and somatic treatments.

Results

Based on the reviewed evidence, this European Psychiatric Association guidance recommends an appropriate pharmacological management as a fundamental starting point in the treatment of cognitive impairment in schizophrenia. In particular, second-generation antipsychotics are recommended for their favorable cognitive profile compared to first-generation antipsychotics, although no clear superiority of a single second-generation antipsychotic has currently been found. Anticholinergic and benzodiazepine burdens should be kept to a minimum, considering the negative impact on cognitive functioning. Among psychosocial interventions, cognitive remediation and physical exercise are recommended for the treatment of cognitive impairment in schizophrenia. Noninvasive brain stimulation techniques could be taken into account as add-on therapy.

Conclusions

Overall, there is definitive progress in the field, but further research is needed to develop specific treatments for cognitive impairment in schizophrenia. The dissemination of this guidance paper may promote the development of shared guidelines concerning the treatment of cognitive functions in schizophrenia, with the purpose to improve the quality of care and to achieve recovery in this population.

Factors influencing the outcome of integrated therapy approach in schizophrenia: A narrative review of the literature

The integration of pharmacotherapy with psychosocial interventions has an important role to play in the improvement of functional outcome of subjects with schizophrenia (SCZ), in all stages of the disorder. It is essential for the adequate management of unmet therapeutic needs, such as negative symptoms and cognitive dysfunctions which account for most of the functional impairment of subjects with SCZ and do not respond to available antipsychotics. Enhancing the knowledge on factors involved in the effectiveness of integrated treatment plans is an important step forward for SCZ care. This review aims to identify factors that might influence the impact of integrated treatments on functional outcome. Most studies on the impact of psychosocial treatments on functional outcome of subjects with SCZ did not control for the effect of prescribed antipsychotics or concomitant medications. However, several factors relevant to ongoing pharmacological treatment might influence the outcome of integrated therapy, with an impact on the adherence to treatment (e.g., therapeutic alliance and polypharmacotherapy) or on illness-related factors addressed by the psychosocial interventions (e.g., cognitive dysfunctions or motivational deficits). Indirect evidence suggests that treatment integration should consider the possible detrimental effects of different antipsychotics or concomitant medications on cognitive functions, as well as on secondary negative symptoms. Cognitive dysfunctions can interfere with participation to an integrated treatment plan and can be worsened by extrapyramidal or metabolic side effects of antipsychotics, or concomitant treatment with anticholinergics or benzodiazepines. Secondary negative symptoms, due to positive symptoms, sedation, extrapyramidal side effects or untreated depression, might cause early drop-out and poor adherence to treatment. Researchers and clinicians should examine all the above-mentioned factors and implement appropriate and personalized integrated treatments to improve the outcome of SCZ.

Impact of anticholinergic load on functioning and cognitive performances of persons with psychosis referred to psychosocial rehabilitation centers

BACKGROUND

Few studies have explored whether high-anticholinergic load may hamper rehabilitation in persons with schizophrenia. We aim to explore the associations between anticholinergic load of psychotropic treatment and functioning or cognitive performances of persons with psychosis engaged in psychosocial rehabilitation.

METHODS

The study was performed using data collected at baseline assessment in the REHABase cohort including persons referred to a French network of psychosocial rehabilitation centers. The composite-rating scale developed by Salahudeen et al. was used to rate the anticholinergic load of psychotropic drugs prescribed at baseline assessment. The associations between total anticholinergic load score (categorized as 'low' <3 v. 'high' ⩾3) and functioning or cognitive characteristics were explored using multivariate analyses.

RESULTS

Of the 1012 participants with schizophrenia spectrum disorders identified in the REHABase, half used at least two psychotropic drugs with anticholinergic activity and one out of three was prescribed at least one psychotropic drug with high-anticholinergic activity. High-anticholinergic load was significantly associated with lower stage of recovery [odds ratio (OR) = 1.70, 95% confidence interval (CI) 1.05-2.76, p = 0.03], poor mental well-being (OR = 1.55, 95% CI 1.02-2.33, p = 0.04) and poor self-rated medication adherence (OR = 2.14, 95% CI 1.29-3.53, p = 0.003). Regarding cognition, a high-anticholinergic score was associated with poorer delayed-episodic memory (OR = 1.69, 95% CI 1.01-2.85, p = 0.05) and at the trend level with faster completion time on the test exploring executive performance (OR = 0.67, 95% CI 0.43-1.04, p = 0.07).

CONCLUSIONS

The psychosocial rehabilitation plan of persons with psychosis should integrate optimization of psychotropic treatment in order to lessen the functional and cognitive impact of high-anticholinergic load.

Evaluation of the frequency following response as a predictive biomarker of response to cognitive training in schizophrenia

Neurophysiological biomarkers of auditory processing show promise predicting outcomes following auditory-based targeted cognitive training (TCT) in schizophrenia, but the viability of the frequency following response (FFR) as a biomarker has yet to be examined, despite its ecological and face validity for auditory-based interventions. FFR is an event-related potential (ERP) that reflects early auditory processing. We predicted that schizophrenia patients would show acute- and longer-term FFR malleability in the context of TCT. Patients were randomized to either TCT (n = 30) or treatment as usual (TAU; n = 22), and electroencephalography was recorded during rapid presentation of an auditory speech stimulus before treatment, after one hour of training, and after 30 h of training. Whereas patients in the TCT group did not show changes in FFR after training, amplitude reductions were observed in the TAU. FFR was positively associated with performance on a measure of single word-in-noise perception in the TCT group, and with a measure of sentence-in-noise perception in both groups. Psychometric reliability analyses of FFR scores indicated high internal consistency but low one-hour and 12-week test-rest reliability. These findings support the dissociation between measures of speech discriminability along the hierarchy of cortical and subcortical early auditory information processing in schizophrenia.

Central auditory processing deficits in schizophrenia: Effects of auditory-based cognitive training

BACKGROUND

Sensory processing abnormalities are common in schizophrenia (SZ) and impact everyday functions, such as speech perception in noisy environments. Auditory-based targeted cognitive training (TCT) is a "bottom up" cognitive remediation intervention designed to enhance the speed and accuracy of low-level auditory information processing. However, the effects of TCT on behavioral measures of central auditory processing (CAP) and the role of CAP function on verbal learning outcomes in SZ are unknown.

METHODS

SZ (n = 42) and healthy subjects (CTL; n = 18) underwent comprehensive clinical, neurocognitive, and auditory assessments, including tests of hearing sensitivity and speech recognition (Words-in-Noise (WIN), Quick Speech-in-Noise (SIN)). SZ patients were randomized to receive either treatment-as-usual (TAU); or 30-h of TCT + TAU using a stratified, parallel design. SZ patients repeated assessments ~10-12 weeks later.

RESULTS

Patients exhibited deficits in both WIN (p < 0.05, d = 0.50) and SIN (p < 0.01, d = 0.63). A treatment × time interaction on WIN (p < 0.05, d = 0.74), but not SIN discriminability, was seen in the TCT group relative to TAU. Specific enhancements in the 4-dB over background range drove gains in WIN performance. Moreover, SZ patients with greater CAP deficits experienced robust gains in verbal learning after 30-h of TCT relative to SZ patients without CAP impairment (p < 0.01, d = 1.28).

CONCLUSION

Findings demonstrate that intensive auditory training enhances the fidelity of auditory processing and perception, such that specific CAP deficits were 'normalized' and were predictive of gains in verbal learning after TCT. It is conceivable that patients with deficiencies in CAP measures may benefit most from TCT and other interventions targeting auditory dysfunction in SZ.

Anticholinergic Medication Burden-Associated Cognitive Impairment in Schizophrenia

OBJECTIVE

Many psychotropic medications used to treat schizophrenia have significant anticholinergic properties, which are linked to cognitive impairment and dementia risk in healthy subjects. Clarifying the impact of cognitive impairment attributable to anticholinergic medication burden may help optimize cognitive outcomes in schizophrenia. The aim of this study was to comprehensively characterize how this burden affects functioning across multiple cognitive domains in schizophrenia outpatients.

METHODS

Cross-sectional data were analyzed using inferential statistics and exploratory structural equation modeling to determine the relationship between anticholinergic medication burden and cognition. Patients with a diagnosis of schizophrenia or schizoaffective disorder (N=1,120) were recruited from the community at five U.S. universities as part of the Consortium on the Genetics of Schizophrenia-2. For each participant, prescribed medications were rated and summed according to a modified Anticholinergic Cognitive Burden (ACB) scale. Cognitive functioning was assessed by performance on domains of the Penn Computerized Neurocognitive Battery (PCNB).

RESULTS

ACB score was significantly associated with cognitive performance, with higher ACB groups scoring worse than lower ACB groups on all domains tested on the PCNB. Similar effects were seen on other cognitive tests. Effects remained significant after controlling for demographic characteristics and potential proxies of illness severity, including clinical symptoms and chlorpromazine-equivalent antipsychotic dosage.

CONCLUSIONS

Anticholinergic medication burden in schizophrenia is substantial, common, conferred by multiple medication classes, and associated with cognitive impairments across all cognitive domains. Anticholinergic medication burden from all medication classes-including psychotropics used in usual care-should be considered in treatment decisions and accounted for in studies of cognitive functioning in schizophrenia.

Quality of anticholinergic burden scales and their impact on clinical outcomes: a systematic review

PURPOSE

Older people are at risk of anticholinergic side effects due to changes affecting drug elimination and higher sensitivity to drug's side effects. Anticholinergic burden scales (ABS) were developed to quantify the anticholinergic drug burden (ADB). We aim to identify all published ABS, to compare them systematically and to evaluate their associations with clinical outcomes.

METHODS

We conducted a literature search in MEDLINE and EMBASE to identify all published ABS and a Web of Science citation (WoS) analysis to track validation studies implying clinical outcomes. Quality of the ABS was assessed using an adapted AGREE II tool. For the validation studies, we used the Newcastle-Ottawa Scale and the Cochrane tool Rob2.0. The validation studies were categorized into six evidence levels based on the propositions of the Oxford Center for Evidence-Based Medicine with respect to their quality. At least two researchers independently performed screening and quality assessments.

RESULTS

Out of 1297 records, we identified 19 ABS and 104 validations studies. Despite differences in quality, all ABS were recommended for use. The anticholinergic cognitive burden (ACB) scale and the German anticholinergic burden scale (GABS) achieved the highest percentage in quality. Most ABS are validated, yet validation studies for newer scales are lacking. Only two studies compared eight ABS simultaneously. The four most investigated clinical outcomes delirium, cognition, mortality and falls showed contradicting results.

CONCLUSION

There is need for good quality validation studies comparing multiple scales to define the best scale and to conduct a meta-analysis for the assessment of their clinical impact.

Gamma oscillations predict pro-cognitive and clinical response to auditory-based cognitive training in schizophrenia

Cognitive impairments are pervasive and disabling features of schizophrenia. Targeted cognitive training (TCT) is a "bottom-up" cognitive remediation intervention with efficacy for neurocognitive outcomes in schizophrenia, yet individual responses are variable. Gamma oscillatory measures are leading candidate biomarkers in the development of biologically informed pro-cognitive therapeutics. Forty-two schizophrenia patients were recruited from a long-term residential treatment facility. Participants were randomized to receive either 1 h of cognitive training (TCT, n = 21) or computer games (TAU, n = 21). All participants received standard-of-care treatment; the TCT group additionally completed 30 h of cognitive training. The auditory steady-state response paradigm was used to elicit gamma oscillatory power and synchrony during electroencephalogram recordings. Detailed clinical and cognitive assessments were collected at baseline and after completion of the study. Baseline gamma power predicted cognitive gains after a full course of TCT (MCCB, R² = 0.31). A change in gamma power after 1-h TCT exposure predicted improvement in both positive (SAPS, R² = 0.40) and negative (SANS, R² = 0.30) symptoms. These relationships were not observed in the TAU group (MCCB, SAPS, and SANS, all R² < 0.06). The results indicate that the capacity to support gamma oscillations, as well as the plasticity of the underlying ASSR circuitry after acute exposure to 1 h of TCT, reflect neural mechanisms underlying the efficacy of TCT, and may be used to predict individualized treatment outcomes. These findings suggest that gamma oscillatory biomarkers applied within the context of experimental medicine designs can be used to personalize individual treatment options for pro-cognitive interventions in patients with schizophrenia.

Auditory-Based Cognitive Training Drives Short- and Long-Term Plasticity in Cortical Networks in Schizophrenia

Schizophrenia patients have widespread deficits in neurocognitive functioning linked to underlying abnormalities in gamma oscillations that are readily measured by the 40 Hz auditory steady-state response (ASSR). Emerging interventions such as auditory-based targeted cognitive training (TCT) improve neurocognitive function in patients. While acute ASSR changes after 1 hour of TCT predict clinical and cognitive gains after a 30-hour course of TCT, the neural substrates of underlying short- and long-term TCT interventions are unknown. To determine the neural substrates underlying TCT-associated ASSR changes, a novel data analysis method was applied to assess the effective connectivity of gamma-band ASSR among estimated cortical sources. In this study, schizophrenia patients (N = 52) were randomized to receive either a treatment as usual (TAU; N = 22) or TAU augmented with TCT (N = 30). EEG recordings were obtained immediately before (T0) and after 1 hour of either computer games (TAU) or cognitive training (TCT; T1), and at 65 ± 15 days (mean ± SD) post-randomization (T2). Results showed increased connectivity from the left ventral middle cingulate gyrus to the left posterior cingulate gyrus, accompanied by decreased connectivity from the left Rolandic operculum (a region that includes auditory cortex) to the right ventral middle cingulate gyrus after 1 hour of TCT. After 30 hours, decreased connectivity from the frontal cortex to a region near the calcarine sulcus were detected. Auditory-based cognitive training drives short- and long-term plasticity in cortical network functioning in schizophrenia patients. These findings may help us understand the mechanisms underlying cognitive training effects in schizophrenia patients and enhance the development of pro-cognitive therapeutics.

Quality of anticholinergic burden scales and their impact on clinical outcomes: a systematic review

Purpose

Older people are at risk of anticholinergic side effects due to changes affecting drug elimination and higher sensitivity to drug’s side effects. Anticholinergic burden scales (ABS) were developed to quantify the anticholinergic drug burden (ADB). We aim to identify all published ABS, to compare them systematically and to evaluate their associations with clinical outcomes.

Methods

We conducted a literature search in MEDLINE and EMBASE to identify all published ABS and a Web of Science citation (WoS) analysis to track validation studies implying clinical outcomes. Quality of the ABS was assessed using an adapted AGREE II tool. For the validation studies, we used the Newcastle-Ottawa Scale and the Cochrane tool Rob2.0. The validation studies were categorized into six evidence levels based on the propositions of the Oxford Center for Evidence-Based Medicine with respect to their quality. At least two researchers independently performed screening and quality assessments.

Results

Out of 1297 records, we identified 19 ABS and 104 validations studies. Despite differences in quality, all ABS were recommended for use. The anticholinergic cognitive burden (ACB) scale and the German anticholinergic burden scale (GABS) achieved the highest percentage in quality. Most ABS are validated, yet validation studies for newer scales are lacking. Only two studies compared eight ABS simultaneously. The four most investigated clinical outcomes delirium, cognition, mortality and falls showed contradicting results.

Conclusion

There is need for good quality validation studies comparing multiple scales to define the best scale and to conduct a meta-analysis for the assessment of their clinical impact.

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02994-x) contains supplementary material, which is available to authorized users.

Individual Alpha Peak Frequency Moderates Transfer of Learning in Cognitive Remediation of Schizophrenia

OBJECTIVE

Meta-analyses report moderate effects across cognitive remediation (CR) trials in schizophrenia. However, individual responses are variable, with some participants showing no appreciable gain in cognitive performance. Furthermore, reasons for heterogeneous outcome are undetermined. We examine the extent to which CR outcome is attributable to near learning-direct gains in trained cognitive tasks-while also exploring factors influencing far transfer of gains during training to external cognitive measures.

METHOD

Thirty-seven schizophrenia outpatients were classified as CR responders and non-responders according to change in MATRICS Consensus Cognitive Battery composite score following 20 sessions of computer-based training. Metrics of near learning during training, as well as baseline demographic, clinical, cognitive, and electroencephalographic (EEG) measures, were examined as predictors of responder status.

RESULTS

Significant post-training improvement in cognitive composite score (Cohen's d = .41) was observed across the sample, with n = 21 and n = 16 classified as responders and non-responders, respectively. Near learning was evidenced by significant improvement on each training exercise with practice; however, learning did not directly predict responder status. Group-wise comparison of responders and non-responders identified two factors favoring responders: higher EEG individual alpha frequency (IAF) and lower antipsychotic dosing. Tested in moderation analyses, IAF interacted with learning to predict improvement in cognitive outcome.

CONCLUSION

CR outcome in schizophrenia is not directly explained by learning during training and appears to depend on latent factors influencing far transfer of trained abilities. Further understanding of factors influencing transfer of learning is needed to optimize CR efficacy.

Deviation from expected cognitive ability is a core cognitive feature of schizophrenia related to neurophysiologic, clinical and psychosocial functioning

Cognitive functioning in schizophrenia is characterized by a generalized impairment in current cognitive ability based on traditional population-based norms. However, these norms assume a normal cognitive trajectory and do not directly account for illness-related declines from expected cognitive potential. Indeed, schizophrenia patients exhibit even greater deviation between their observed and expected cognitive functioning based on expanded norms that leverage premorbid variables resistant to illness-related features. The current study further quantified the extent to which illness-related features account for this deviation from expectation and assessed its relationship to neurophysiologic (mismatch negativity, P3a, theta oscillations), clinical, and psychosocial functioning in schizophrenia patients. Expected cognitive ability (PENN-CNB global cognition) in patients (n = 684) was calculated using healthy comparison subject (n = 660) weighted regression based on premorbid variables resistant to illness-related decline (demographics, single-word reading, parental education). The magnitude of any deviation between current (observed) and regression-predicted (expected) cognitive ability was calculated. Results indicated that 24% (n = 164) of the total patient population exhibited significant (≥-1.96 SD) deviation between observed and expected global cognitive ability. Interestingly, 20% of the total patient population (n = 136) had "normal" range cognitive performance when using traditional population-based norms, but also had significant deviation from expected cognitive ability. The magnitude of this deviation was associated with more severe neurophysiologic abnormalities, longer illness duration, higher levels of negative symptoms, and worse psychosocial functioning. Assessment of cognitive deviation is thus a complementary metric for characterizing the severity of illness-related cognitive declines in patients, while also reflecting the expression and severity of key endophenotypes of schizophrenia.

Mismatch negativity reveals plasticity in cortical dynamics after 1-hour of auditory training exercises

BACKGROUND

Impaired sensory processing contributes to deficits in cognitive and psychosocial functioning in individuals with schizophrenia (SZ). Mismatch Negativity (MMN), an event-related potential (ERP) index of sensory discrimination associated with cognitive and psychosocial functioning, is a candidate biomarker of auditory discrimination and thus possibly of changes following auditory-based Targeted Cognitive Training (TCT). Here we evaluated the acute effect of TCT on cortical processes supporting auditory discrimination.

METHODS

MMN was assessed in 28 SZ outpatients before and after a single 1-hour (hr) session of "Sound Sweeps," a pitch discrimination task that is a component of the TCT suite of exercises. Independent component (IC) analysis was applied to decompose 64-channel scalp-recorded electroencephalogram (EEG) activity into spatiotemporally stationary sources and their activities. ICs from all patients were pooled to find commonalities in their cortical locations. IC cluster-mean ERPs were evaluated to determine the clusters contributing to the (140-200 ms) MMN difference between responses to deviant and standard tone stimuli respectively.

RESULTS

Two frontal IC clusters centered in orbitofrontal cortex (OFC) and anterior cingulate cortex (ACC) accounted for >77% of MMN variance across all scalp channels. After 1-hr auditory training, significant suppression of ACC cluster contributions was detected, whereas the OFC cluster contribution was unchanged.

CONCLUSIONS

Prior to TCT, the MMN response was dominated by EEG effective sources in or near OFC and ACC. However, after 1-hr of auditory-based TCT, a significant attenuation of ACC was observed, whereas OFC contribution to MMN persisted. The present findings support further trials designed to test whether training-related MMN plasticity in the ACC after 1-hr may predict individual patient response to a full course of TCT.