Treatment response heterogeneity in the predominant negative symptoms of schizophrenia: analysis of amisulpride vs placebo in three clinical trials

Attenuated niacin response is associated with a subtype of first-episode drug-naïve psychosis characterized as serious negative symptoms

Although the phenomenon of attenuated niacin response (ANR) has been widely replicated in some patients with first-episode psychosis (FEP), its relevance to the negative symptoms (NS) of psychosis remains unclear. Total of 240 patients with drug-naïve FEP and 101 healthy controls (HCs) were recruited, and 209 were followed up for 1 year. Psychotic symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS), and niacin-induced responses were measured using laser Doppler flowmetry. We calculated the log-transform EC50 [concentration of methyl nicotinate required to elicit a half-maximal blood flow (MBF) response] and MBF values. Core-NS was generated by factor analysis of the PANSS-NS subscale and cluster analysis to produce subtypes. Significant differences were found in the log10 (EC50) values between the FEP and HC groups (p < 0.001), supporting the ANR in patients with FEP. A higher NS severity was found in the ANR subgroup than that in other patients. Factor analysis determined that a two-dimensional model included core NS and rigidity of thinking. The log10 (EC50) value was significantly associated with only the core NS. Cluster analysis revealed three subtypes-36.7% (cluster-1, n = 88), 16.7% (cluster-2, n = 40), and 46.7% (cluster-3, n = 112). Cluster-2 characterized by extensive NS appeared to have a more remarkable ANR and less symptomatic improvement than those with other clusters during follow-up. No significant changes were found in the niacin response trajectories between the baseline and follow-up. Our findings indicate a significant correlation between ANR and core NS in patients with FEP. ANR may be a potential biomarker for certain subtypes with NS-dominated characteristics and poor symptomatic remission.

Single trajectory treatment response for predominant negative symptoms: Post-hoc analysis of a clinical trial with cariprazine and risperidone

Examining the heterogeneity of negative symptoms of schizophrenia contributes to the identification of available treatment targets. Generally, prior evidence classified three to four symptom treatment response trajectory groups over the course of positive symptoms, yet, no evidence exists regarding the heterogeneity of medium-term response to predominant negative symptoms. The current post-hoc analysis aims to identify the heterogeneity in negative symptom treatment response trajectories among patients with predominant negative symptoms who received either cariprazine or risperidone for 26 weeks. Treatment response was analyzed based on the: the Positive and Negative Syndrome Scale Factor Score for Negative Symptoms (PANSS-FSNS), and the Clinical Global Impression Severity (CGIS) and Improvement (CGII) scales. To identify subgroups of patients with a similar course of treatment response, group-based trajectory modelling was utilized. Results demonstrated that in comparison with competing models, a single trajectory best described the treatment response of patients with predominant negative symptoms. The results indicate that patients with predominant negative symptoms with over ten years of schizophrenia respond rapidly to adequate treatment and follow a course of steady improvement.

Rasch analysis of the PANSS negative subscale and exploration of negative symptom trajectories in first-episode schizophrenia - data from the OPTiMiSE trial

The observed heterogeneity in negative symptom treatment response may be partly attributable to inadequate measurement tools or limitations in methods of analysis. Previous Item Response Theory models of the Positive and Negative Syndrome Scale (PANSS) have only examined samples of chronic patients and with mixed results. We examined the scalability of the negative subscale embedded in the PANSS and subsequently explored negative symptom trajectories across four weeks of amisulpride treatment. Data were derived from the OPTiMiSE trial comprising 446 patients with first-episode schizophrenia or schizophreniform disorder. Using the Rasch Model to examine psychometric properties of the PANSS negative subscale, we found that the composite score across items was not an adequate measure of negative symptom severity. Consequently, we chose an exploratory statistical approach involving Principal Component Analysis which yielded one significant component clustering into two significant symptom trajectories: 1) Subtle but constant decrease in negative symptom severity (N = 323; 72%), and 2) symptom instability across visits (N = 19; 4%). Explorative analytic methods as presented here may pave the way for more efficient and sensitive methods of analyzing negative symptom response in research and in clinical practice.

Trajectory and early predictors of apathy development in first-episode psychosis and healthy controls: a 10-year follow-up study

Apathy is prevalent in first-episode psychosis (FEP) and associated with reduced global functioning. Investigations of the trajectory of apathy and its early predictors are needed to develop new treatment interventions. We here measured the levels of apathy over the first 10 years of treatment in FEP and in healthy controls (HC). We recruited 198 HC and 198 FEP participants. We measured apathy with the Apathy Evaluation Scale, self-report version, psychotic symptoms with the Positive and Negative Syndrome Scale, depression with the Calgary Depression Scale for Schizophrenia, functioning with the Global Assessment of Functioning Scale, and also estimated the duration of untreated psychosis (DUP). The longitudinal development of apathy and its predictors were explored using linear mixed models analyses. Associations to functioning at 10 years were investigated using multiple hierarchical linear regression analyses. In HC, mean apathy levels were low and stable. In FEP, apathy levels decreased significantly during the first year of treatment, followed by long-term stability. High individual levels of apathy at baseline were associated with higher apathy levels during the follow-up. Long DUP and high baseline levels of depression predicted higher apathy levels at follow-ups. The effect of DUP was persistent, while the effect of baseline depression decreased over time. At 10 years, apathy was statistically significantly associated with reduced functioning. The early phase of the disorder may be critical to the development of apathy in FEP.

Pharmacological treatment of negative symptoms in schizophrenia: update and proposal of a clinical algorithm

The clinical presentation of schizophrenia encompasses symptoms divided into three dimensions: positive, negative, and cognitive. Negative symptoms (NS), in particular, have a major impact on the quality of life of the affected subject, and, differing from positive symptoms, are often associated with a limited response to pharmacotherapy. To date, studies specifically investigating NS in schizophrenia are scant; therefore, proper selection of therapy for NS remains a major unmet medical need. Given the heterogeneity of the clinical presentation of schizophrenia, the treatment of NS, as well as therapy for other associated symptoms, should be largely individualized according to a patient's specific characteristics. In this paper, we review current knowledge on NS and construct a clinical algorithm for the treatment of schizophrenic conditions with pronounced NS. Overall, data from the literature suggest that second-generation antipsychotics, such as cariprazine and amisulpride, should be preferred over first-generation antipsychotics (FGAs), as they are associated with better functional outcomes and lower cognitive impairment. The combination of antipsychotics and antidepressants may also improve NS while addressing some affective disorders associated with schizophrenia; however, no clear information is available on the effects of this combination on primary NS or on the mechanism of action of the combination. In the proposed clinical algorithm, we suggest that cariprazine should be used as first-line treatment for patients with predominant NS, and that amisulpride should be considered as an alternative in cases of cariprazine failure. Further treatment lines may include the use of olanzapine and quetiapine, and add-on therapy with antidepressants.

Covariation between motor signs and negative symptoms in drug-naive subjects with schizophrenia-spectrum disorders before and after antipsychotic treatment

OBJECTIVE

To examine the covariation between negative symptoms and motor signs in a broad sample of drug-naïve subjects with schizophrenia-spectrum psychoses before and after inception of antipsychotic medication.

METHODS

One-hundred and eighty-nine antipsychotic-naïve subjects with DSM-IV schizophrenia-spectrum psychoses were assessed for negative symptoms including affective flattening, alogia, avolition/apathy and anhedonia/associality, and motor signs including catatonia, parkinsonism and dyskinesia. We examined the association between negative and motor features at baseline, 4-weeks after inception of antipsychotic treatment and that of their mean change over the treatment period, such as their trajectories and treatment response pattern.

RESULTS

At the drug-naïve state, motor signs were strongly related to affective flattening and alogia (p<0.01); at 4-weeks, most negative and motor features were significantly interrelated (p<0.01); mean change of motor signs and negative symptoms tended to be unrelated. This association pattern was irrespective of levels of positive symptoms. Ratings of negative symptoms, excepting affective flattening, improved after treatment (p<0.001) while motor ratings showed divergent trajectories with catatonia improving (p<0.001), parkinsonism worsening (p<0.001) and dyskinesia remaining unchanged (p>0.01). Although to a different extent, motor and negative features showed drug-responsive, drug-worsening, of drug-unchanged patterns of response to antipsychotic medication. The main predictors of negative and motor features in treated subjects were their corresponding baseline ratings (p<0.001).

CONCLUSIONS

Negative and motor features are differentiated, but to some extent, overlapping domains that are meaningfully influenced by antipsychotic medication. At the drug-naïve state, motor signs and the diminished expression domain of negative symptoms may share underlying neurobiological mechanisms.

Negative symptoms of psychosis: A life course approach and implications for prevention and treatment

AIM

Negative symptoms are a cause of enduring disability in serious mental illness. In spite of this, the development of effective treatments for negative symptoms has remained slow. The challenge of improving negative symptom outcomes is compounded by our limited understanding of their aetiology and longitudinal development.

METHODS

A literature search was conducted for life course approach of negative symptoms using PubMed. Further articles were included following manual checking of reference lists and other search strategies. The paper contains a theoretical synthesis of the literature, summarized using conceptual models.

RESULTS

Negative symptom definitions are compared and considered within a context of the life course. Previous studies suggest that several illness phases may contribute to negative symptoms, highlighting our uncertainty in relation to the origin of negative symptoms.

CONCLUSIONS

Similar to other aspects of schizophrenia, negative symptoms likely involve a complex interplay of several risk and protective factors at different life phases. Concepts suggested in this article, such as "negative symptom reserve" theory, require further research, which may inform future prevention and treatment strategies.

Negative Symptoms and Reward Disturbances in Schizophrenia Before and After Antipsychotic Monotherapy

BACKGROUND

Negative symptoms (NS) are a central part of the symptomatology of schizophrenia, which is highly correlated to the functional outcome. Disturbances of the brain reward system are suggested to be central in the pathogenesis of NS by decreasing motivation and hedonic experiences. In this study, we compared reward-related brain activity in patients improving and not improving in NS after treatment with amisulpride.

METHODS

Thirty-nine antipsychotic-naive patients and 49 healthy controls completed functional magnetic resonance imaging with a modified monetary incentive delay task. Psychopathology of the patients was characterised with Positive and Negative Syndrome Scale (PANSS), and they were treated with individual doses of amisulpride (mean 271 mg) for 6 weeks, after which the examinations were repeated.

RESULTS

Patients improved on positive, general, and total PANSS score after treatment ( P < .001). Fourteen patients had ≥20% improvement of NS, whereas 25 patients improved <20%. At baseline, one-way analysis of variance showed group difference bilaterally in the caudate nucleus and in the right nucleus accumbens (all P < .002), which was caused by decreased reward anticipation activity in the nonimproving patients compared to healthy controls. There was a significant group × time interaction, with the healthy controls and the improvers decreasing and the nonimprovers increasing in reward anticipation activity after treatment, most pronounced in the left caudate nucleus ( P = .001).

DISCUSSION

Patients improving in NS score had a less aberrant reward system at baseline, but reward related activity was reduced over time. Patients not improving in NS showed decreased striatal reward-activity at baseline, which improved over time. Whether this is associated with alteration in working memory and reward learning or with pronounced symptoms within specific domains of NS may be addressed in future studies.

Effects of cognitive remediation on negative symptoms dimensions: exploring the role of working memory

BACKGROUND

Recent theories suggest that poor working memory (WM) may be the cognitive underpinning of negative symptoms in people with schizophrenia. In this study, we first explore the effect of cognitive remediation (CR) on two clusters of negative symptoms (i.e. expressive and social amotivation), and then assess the relevance of WM gains as a possible mediator of symptom improvement.

METHOD

Data were accessed for 309 people with schizophrenia from the NIMH Database of Cognitive Training and Remediation Studies and a separate study. Approximately half the participants received CR and the rest were allocated to a control condition. All participants were assessed before and after therapy and at follow-up. Expressive negative symptoms and social amotivation symptoms scores were calculated from the Positive and Negative Syndrome Scale. WM was assessed with digit span and letter-number span tests.

RESULTS

Participants who received CR had a significant improvement in WM scores (d = 0.27) compared with those in the control condition. Improvements in social amotivation levels approached statistical significance (d = -0.19), but change in expressive negative symptoms did not differ between groups. WM change did not mediate the effect of CR on social amotivation.

CONCLUSIONS

The results suggest that a course of CR may benefit behavioural negative symptoms. Despite hypotheses linking memory problems with negative symptoms, the current findings do not support the role of this cognitive domain as a significant mediator. The results indicate that WM improves independently from negative symptoms reduction.

Two subgroups of antipsychotic-naive, first-episode schizophrenia patients identified with a Gaussian mixture model on cognition and electrophysiology

Deficits in information processing and cognition are among the most robust findings in schizophrenia patients. Previous efforts to translate group-level deficits into clinically relevant and individualized information have, however, been non-successful, which is possibly explained by biologically different disease subgroups. We applied machine learning algorithms on measures of electrophysiology and cognition to identify potential subgroups of schizophrenia. Next, we explored subgroup differences regarding treatment response. Sixty-six antipsychotic-naive first-episode schizophrenia patients and sixty-five healthy controls underwent extensive electrophysiological and neurocognitive test batteries. Patients were assessed on the Positive and Negative Syndrome Scale (PANSS) before and after 6 weeks of monotherapy with the relatively selective D₂ receptor antagonist, amisulpride (280.3±159 mg per day). A reduced principal component space based on 19 electrophysiological variables and 26 cognitive variables was used as input for a Gaussian mixture model to identify subgroups of patients. With support vector machines, we explored the relation between PANSS subscores and the identified subgroups. We identified two statistically distinct subgroups of patients. We found no significant baseline psychopathological differences between these subgroups, but the effect of treatment in the groups was predicted with an accuracy of 74.3% (P=0.003). In conclusion, electrophysiology and cognition data may be used to classify subgroups of schizophrenia patients. The two distinct subgroups, which we identified, were psychopathologically inseparable before treatment, yet their response to dopaminergic blockade was predicted with significant accuracy. This proof of principle encourages further endeavors to apply data-driven, multivariate and multimodal models to facilitate progress from symptom-based psychiatry toward individualized treatment regimens.

Effectiveness of amisulpride in Chinese patients with predominantly negative symptoms of schizophrenia: a subanalysis of the ESCAPE study

BACKGROUND

Effective management strategies for the negative symptoms of schizophrenia remain an unmet need, and data on the use of antipsychotics in this population are scarce, particularly in Chinese patients. Therefore, we investigated amisulpride for the treatment of Chinese patients with predominantly negative symptoms of schizophrenia.

METHODS

This post hoc subanalysis of the prospective Effectiveness and Safety of Amisulpride in Chinese Patients with Schizophrenia (ESCAPE) study included adult Chinese patients with an International Classification of Diseases-10 diagnosis of schizophrenia and predominantly negative symptoms, who received amisulpride for 8 weeks. Effectiveness outcomes included ≥50% decrease in Positive and Negative Syndrome Scale (PANSS) negative score, and a reduction in PANSS negative symptom score and Clinical Global Impression Severity Scale (CGI-S). The study was registered at ClinicalTrials.gov (NCT01795183).

RESULTS

In total, 26 patients were included in the analysis. A ≥50% decrease in PANSS negative score from baseline to week 8 was achieved by 34.6% of patients. From baseline to week 8, the mean PANSS negative symptom score decreased by 45.2% (31.9 to 20.7) and CGI-S decreased 1.9 points (5.2 to 3.3). The mean week 8 dose of amisulpride was lower for patients who achieved a ≥50% decrease in PANSS negative score at week 8 versus those who did not (481.2 vs 704.1 mg/day). The most common treatment-related adverse events included blood prolactin increase (19.2%) and extrapyramidal disorder (19.2%). Weight gain was reported by one patient.

CONCLUSION

Amisulpride effectively reduced PANSS negative symptom score and CGI-S for Chinese patients with predominantly negative symptoms of schizophrenia. No unexpected adverse events were reported.

Identifying a system of predominant negative symptoms: Network analysis of three randomized clinical trials

BACKGROUND

Reasons for the recent mixed success of research into negative symptoms may be informed by conceptualizing negative symptoms as a system that is identifiable from network analysis. We aimed to identify: (I) negative symptom systems; (I) central negative symptoms within each system; and (III) differences between the systems, based on network analysis of negative symptoms for baseline, endpoint and change.

METHODS

Patients with chronic schizophrenia and predominant negative symptoms participated in three clinical trials that compared placebo and amisulpride to 60days (n=487). Networks analyses were computed from the Scale for the Assessment of Negative Symptoms (SANS) scores for baseline and endpoint for severity, and estimated change based on mixed models. Central symptoms to each network were identified. The networks were contrasted for connectivity with permutation tests.

RESULTS

Network analysis showed that the baseline and endpoint symptom severity systems formed symptom groups of Affect, Poor responsiveness, Lack of interest, and Apathy-inattentiveness. The baseline and endpoint networks did not significantly differ in terms of connectivity, but both significantly (P<0.05) differed to the change network. In the change network the apathy-inattentiveness symptom group split into three other groups. The most central symptoms were Decreased Spontaneous Movements at baseline and endpoint, and Poverty of Speech for estimated change.

CONCLUSIONS

Results provide preliminary evidence for: (I) a replicable negative symptom severity system; and (II) symptoms with high centrality (e.g., Decreased Spontaneous Movement), that may be future treatment targets following replication to ensure the curent results generalize to other samples.

Treating Negative Symptoms in Schizophrenia: an Update

Interest in the negative symptoms of schizophrenia has increased rapidly over the last several decades, paralleling a growing interest in functional, in addition to clinical, recovery, and evidence underscoring the importance negative symptoms play in the former. Efforts continue to better define and measure negative symptoms, distinguish their impact from that of other symptom domains, and establish effective treatments as well as trials to assess these. Multiple interventions have been the subject of investigation, to date, including numerous pharmacological strategies, brain stimulation, and non-somatic approaches. Level and quality of evidence vary considerably, but to this point, no specific treatment can be recommended. This is particularly problematic for individuals burdened with negative symptoms in the face of mild or absent positive symptoms. Presently, clinicians will sometimes turn to interventions that are seen as more “benign” and in line with routine clinical practice. Strategies include use of atypical antipsychotics, ensuring the lowest possible antipsychotic dose that maintains control of positive symptoms (this can involve a shift from antipsychotic polypharmacy to monotherapy), possibly an antidepressant trial (given diagnostic uncertainty and the frequent use of these drugs in schizophrenia), and non-somatic interventions (e.g., cognitive behavioral therapy, CBT). The array and diversity of strategies currently under investigation highlight the lack of evidence-based treatments and our limited understanding regarding negative symptoms underlying etiology and pathophysiology. Their onset, which can precede the first psychotic break, also means that treatments are delayed. From this perspective, identification of biomarkers and/or endophenotypes permitting earlier diagnosis and intervention may serve to improve treatment efficacy as well as outcomes.

Clinical predictors of therapeutic response to antipsychotics in schizophrenia

The search for clinical outcome predictors for schizophrenia is as old as the field of psychiatry. However, despite a wealth of large, longitudinal studies into prognostic factors, only very few clinically useful outcome predictors have been identified. The goal of future treatment is to either affect modifiable risk factors, or use nonmodifiable factors to parse patients into therapeutically meaningful subgroups. Most clinical outcome predictors are nonspecific and/or nonmodifiable. Nonmodifiable predictors for poor odds of remission include male sex, younger age at disease onset, poor premorbid adjustment, and severe baseline psychopathology. Modifiable risk factors for poor therapeutic outcomes that clinicians can act upon include longer duration of untreated illness, nonadherence to antipsychotics, comorbidities (especially substance-use disorders), lack of early antipsychotic response, and lack of improvement with non-clozapine antipsychotics, predicting clozapine response. It is hoped that this limited capacity for prediction will improve as pathophysiological understanding increases and/or new treatments for specific aspects of schizophrenia become available.

Introducing the fit-criteria assessment plot - A visualisation tool to assist class enumeration in group-based trajectory modelling

Background and objective Group-based trajectory modelling is a model-based clustering technique applied for the identification of latent patterns of temporal changes. Despite its manifold applications in clinical and health sciences, potential problems of the model selection procedure are often overlooked. The choice of the number of latent trajectories (class-enumeration), for instance, is to a large degree based on statistical criteria that are not fail-safe. Moreover, the process as a whole is not transparent. To facilitate class enumeration, we introduce a graphical summary display of several fit and model adequacy criteria, the fit-criteria assessment plot. Methods An R-code that accepts universal data input is presented. The programme condenses relevant group-based trajectory modelling output information of model fit indices in automated graphical displays. Examples based on real and simulated data are provided to illustrate, assess and validate fit-criteria assessment plot's utility. Results Fit-criteria assessment plot provides an overview of fit criteria on a single page, placing users in an informed position to make a decision. Fit-criteria assessment plot does not automatically select the most appropriate model but eases the model assessment procedure. Conclusions Fit-criteria assessment plot is an exploratory, visualisation tool that can be employed to assist decisions in the initial and decisive phase of group-based trajectory modelling analysis. Considering group-based trajectory modelling's widespread resonance in medical and epidemiological sciences, a more comprehensive, easily interpretable and transparent display of the iterative process of class enumeration may foster group-based trajectory modelling's adequate use.

Trajectories of Scores on a Screening Instrument for PTSD Among World Trade Center Rescue, Recovery, and Clean-Up Workers

The longitudinal course of posttraumatic stress disorder (PTSD) over 8-9 years was examined among 16,488 rescue and recovery workers who responded to the events of September 11, 2001 (9/11) at the World Trade Center (WTC; New York, NY), and were enrolled in the World Trade Center Health Registry. Latent class growth analysis identified 5 groups of rescue and recovery workers with similar score trajectories at 3 administrations of the PTSD Checklist (PCL): low-stable (53.3%), moderate- stable (28.7%), moderate-increasing (6.4%), high-decreasing (7.7%), and high-stable (4.0%). Relative to the low-stable group, membership in higher risk groups was associated with 9/11-related exposures including duration of WTC work, with adjusted odds ratios ranging from 1.3 to 2.0, witnessing of horrific events (range = 1.3 to 2.1), being injured (range = 1.4 to 2.3), perceiving threat to life or safety (range = 2.2 to 5.2), bereavement (range = 1.6 to 4.8), and job loss due to 9/11 (range = 2.4 to 15.8). Within groups, higher PCL scores were associated with adverse social circumstances including lower social support, with B coefficients ranging from 0.2 to 0.6, divorce, separation, or widowhood (range = 0.4-0.7), and unemployment (range = 0.4-0.5). Given baseline, exposure-related, and contextual influences that affect divergent PTSD trajectories, screening for both PTSD and adverse circumstances should occur immediately, and at regular intervals postdisaster.