Glutamatergic and dopaminergic function and the relationship to outcome in people at clinical high risk of psychosis: a multi-modal PET-magnetic resonance brain imaging study

Abstract Preclinical models of psychosis propose that hippocampal glutamatergic neuron hyperactivity drives increased striatal dopaminergic activity, which underlies the development of psychotic symptoms. The aim of this study was to examine the relationship between hippocampal glutamate and subcortical dopaminergic function in people at clinical high risk for psychosis, and to assess the association with the development of psychotic symptoms. 1H-MRS was used to measure hippocampal glutamate concentrations, and 18F-DOPA PET was used to measure dopamine synthesis capacity in 70 subjects (51 people at clinical high risk for psychosis and 19 healthy controls). Clinical assessments were undertaken at baseline and follow-up (median 15 months). Striatal dopamine synthesis capacity predicted the worsening of psychotic symptoms at follow-up (r = 0.35; p < 0.05), but not transition to a psychotic disorder (p = 0.22), and was not significantly related to hippocampal glutamate concentration (p = 0.13). There were no differences in either glutamate (p = 0.5) or dopamine (p = 0.5) measures in the total patient group relative to controls. Striatal dopamine synthesis capacity at presentation predicts the subsequent worsening of sub-clinical total and psychotic symptoms, consistent with a role for dopamine in the development of psychotic symptoms, but is not strongly linked to hippocampal glutamate concentrations.

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Interactions between hippocampal activity and striatal dopamine in people at clinical high risk for psychosis: relationship to clinical outcomes

10.1101/2020.12.08.20245902 ◽

2020 ◽

Author(s):

Gemma Modinos ◽

Anja Richter ◽

Alice Egerton ◽

Ilaria Bonoldi ◽

Matilda Azis ◽

...

Keyword(s):

High Risk ◽

Functional Outcome ◽

Clinical Outcomes ◽

Striatal Dopamine ◽

Psychotic Symptoms ◽

Dopamine Synthesis ◽

Clinical High Risk ◽

Hippocampal Activity ◽

The Relationship

AbstractBackgroundPreclinical models propose that the onset of psychosis involves increased hippocampal activity which drives subcortical dopaminergic dysfunction. We used multi-modal neuroimaging to examine the relationship between hippocampal regional cerebral blood flow (rCBF) and striatal dopamine synthesis capacity in people at clinical high risk (CHR) for psychosis, and investigated its association with subsequent clinical outcomes.MethodsNinety-five participants (67 CHR and 28 healthy controls) underwent pseudo-continuous arterial spin labelling and 18F-DOPA PET imaging at baseline. Clinical outcomes in CHR participants were determined after a median of 15 months follow-up, using the Comprehensive Assessment of At Risk Mental States (CAARMS) and the Global Assessment of Function (GAF) scale.ResultsCHR participants with a poor functional outcome (follow-up GAF<65, n=25) showed higher rCBF in the right hippocampus compared to CHRs with a good functional outcome (GAF≥65, n=25) (familywise error [FWE] p=0·026). The relationship between right hippocampal rCBF and striatal dopamine synthesis capacity was also significantly different between groups (pFWE=0·035); the association was negative in CHR with poor outcomes (pFWE=0·012), but non-significant in CHR with good outcomes. The correlation between rCBF in this right hippocampal region and striatal dopamine function also predicted a longitudinal increase in the severity of positive psychotic symptoms (p=0·041). The relationship between hippocampal rCBF and striatal dopamine did not differ in the total CHR group relative to controls.InterpretationThese findings indicate that altered interactions between the hippocampus and the subcortical dopamine system are implicated in the pathophysiology of psychosis-related outcomes.

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Interactions between hippocampal activity and striatal dopamine in people at clinical high risk for psychosis: relationship to adverse outcomes

Neuropsychopharmacology ◽

10.1038/s41386-021-01019-0 ◽

2021 ◽

Author(s):

Gemma Modinos ◽

Anja Richter ◽

Alice Egerton ◽

Ilaria Bonoldi ◽

Matilda Azis ◽

...

Keyword(s):

High Risk ◽

Functional Outcomes ◽

Mental States ◽

Adverse Outcomes ◽

Striatal Dopamine ◽

Psychotic Symptoms ◽

Dopamine Synthesis ◽

Clinical High Risk ◽

Hippocampal Activity ◽

The Relationship

AbstractPreclinical models propose that increased hippocampal activity drives subcortical dopaminergic dysfunction and leads to psychosis-like symptoms and behaviors. Here, we used multimodal neuroimaging to examine the relationship between hippocampal regional cerebral blood flow (rCBF) and striatal dopamine synthesis capacity in people at clinical high risk (CHR) for psychosis and investigated its association with subsequent clinical and functional outcomes. Ninety-five participants (67 CHR and 28 healthy controls) underwent arterial spin labeling MRI and 18F-DOPA PET imaging at baseline. CHR participants were followed up for a median of 15 months to determine functional outcomes with the global assessment of function (GAF) scale and clinical outcomes using the comprehensive assessment of at-risk mental states (CAARMS). CHR participants with poor functional outcomes (follow-up GAF < 65, n = 25) showed higher rCBF in the right hippocampus compared to CHRs with good functional outcomes (GAF ≥ 65, n = 25) (pfwe = 0.026). The relationship between rCBF in this right hippocampal region and striatal dopamine synthesis capacity was also significantly different between groups (pfwe = 0.035); the association was negative in CHR with poor outcomes (pfwe = 0.012), but non-significant in CHR with good outcomes. Furthermore, the correlation between right hippocampal rCBF and striatal dopamine function predicted a longitudinal increase in the severity of positive psychotic symptoms within the total CHR group (p = 0.041). There were no differences in rCBF, dopamine, or their associations in the total CHR group relative to controls. These findings indicate that altered interactions between the hippocampus and the subcortical dopamine system are implicated in the pathophysiology of adverse outcomes in the CHR state.

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Two-year follow-up of a Chinese sample at clinical high risk for psychosis: timeline of symptoms, help-seeking and conversion

Epidemiology and Psychiatric Sciences ◽

10.1017/s2045796016000184 ◽

2016 ◽

Vol 26 (3) ◽

pp. 287-298 ◽

Cited By ~ 21

Author(s):

T. H. Zhang ◽

H. J. Li ◽

K. A. Woodberry ◽

L. H. Xu ◽

Y. Y. Tang ◽

...

Keyword(s):

High Risk ◽

Symptom Onset ◽

Help Seeking ◽

Cox Regression ◽

Clinical Population ◽

Psychotic Symptoms ◽

Clinical High Risk ◽

Chinese Sample ◽

Over Time

Background.Chinese psychiatrists have gradually started to focus on those who are deemed to be at ‘clinical high-risk (CHR)’ for psychosis; however, it is still unknown how often those individuals identified as CHR from a different country background than previously studied would transition to psychosis. The objectives of this study are to examine baseline characteristics and the timing of symptom onset, help-seeking, or transition to psychosis over a 2-year period in China.Method.The presence of CHR was determined with the Structured Interview for Prodromal Syndromes (SIPS) at the participants' first visit to the mental health services. A total of 86 (of 117) CHR participants completed the clinical follow-up of at least 2 years (73.5%). Conversion was determined using the criteria of presence of psychotic symptoms (in SIPS). Analyses examined baseline demographic and clinical predictors of psychosis and trajectory of symptoms over time. Survival analysis (Kaplan–Meier) methods along with Log-rank tests were performed to illustrate the relationship of baseline data to either conversion or non-conversion over time. Cox regression was performed to identify baseline predictors of conversion by the 2-year follow-up.Results.In total 25 (29.1%) of 86 completers transitioned to a psychotic disorder over the course of follow-up. Among the CHR sample, the mean time between attenuated symptom onset and professional help-seeking was about 4 months on average, and converters developed fully psychotic symptoms about 12 months after symptom onset. Compared with those CHR participants whose risk syndromes remitted over the course of the study, converters had significantly longer delays (p = 0.029) for their first visit to a professional in search of help. At baseline assessment, the conversion subgroup was younger, had poorer functioning, higher total SIPS positive symptom scores, longer duration of untreated prodromal symptoms, and were more often given psychosis-related diagnoses and subsequently prescribed antipsychotics in the clinic.Conclusions.Chinese CHR identified primarily by a novel clinical screening approach had a 2-year transition rate comparable with those of specialised help-seeking samples world-wide. Early clinical intervention with this functionally deteriorating clinical population who are suffering from attenuated psychotic symptoms, is a next step in applying the CHR construct in China.

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Characterising cognitive heterogeneity in individuals at clinical high-risk for psychosis: a cluster analysis with clinical and functional outcome prediction

European Archives of Psychiatry and Clinical Neuroscience ◽

10.1007/s00406-021-01315-2 ◽

2021 ◽

Author(s):

Kate Haining ◽

Ruchika Gajwani ◽

Joachim Gross ◽

Andrew I. Gumley ◽

Robin A. A. Ince ◽

...

Keyword(s):

Cluster Analysis ◽

High Risk ◽

Functional Outcomes ◽

Early Stage ◽

Psychotic Symptoms ◽

First Episode ◽

Cognitively Impaired ◽

Clinical High Risk ◽

Global Functioning

AbstractSchizophrenia is characterised by cognitive impairments that are already present during early stages, including in the clinical high-risk for psychosis (CHR-P) state and first-episode psychosis (FEP). Moreover, data suggest the presence of distinct cognitive subtypes during early-stage psychosis, with evidence for spared vs. impaired cognitive profiles that may be differentially associated with symptomatic and functional outcomes. Using cluster analysis, we sought to determine whether cognitive subgroups were associated with clinical and functional outcomes in CHR-P individuals. Data were available for 146 CHR-P participants of whom 122 completed a 6- and/or 12-month follow-up; 15 FEP participants; 47 participants not fulfilling CHR-P criteria (CHR-Ns); and 53 healthy controls (HCs). We performed hierarchical cluster analysis on principal components derived from neurocognitive and social cognitive measures. Within the CHR-P group, clusters were compared on clinical and functional variables and examined for associations with global functioning, persistent attenuated psychotic symptoms and transition to psychosis. Two discrete cognitive subgroups emerged across all participants: 45.9% of CHR-P individuals were cognitively impaired compared to 93.3% of FEP, 29.8% of CHR-N and 30.2% of HC participants. Cognitively impaired CHR-P participants also had significantly poorer functioning at baseline and follow-up than their cognitively spared counterparts. Specifically, cluster membership predicted functional but not clinical outcome. Our findings support the existence of distinct cognitive subgroups in CHR-P individuals that are associated with functional outcomes, with implications for early intervention and the understanding of underlying developmental processes.

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Duration of basic and attenuated-psychotic symptoms in individuals at clinical high risk for psychosis: pattern of symptom onset and effects of duration on functioning and cognition

BMC Psychiatry ◽

10.1186/s12888-021-03267-2 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Lorna Staines ◽

Ruchika Gajwani ◽

Joachim Gross ◽

Andrew I. Gumley ◽

Stephen M. Lawrie ◽

...

Keyword(s):

High Risk ◽

Cognitive Deficits ◽

Psychotic Symptoms ◽

Healthy Controls ◽

Clinical High Risk ◽

Basic Symptoms ◽

Secondary Objective ◽

Secondary Phenomenon ◽

The Relationship ◽

At Risk Mental State

Abstract Introduction Duration of risk symptoms (DUR) in people at clinical high risk for psychosis (CHR-P) has been related to poorer clinical outcomes, such as reduced functioning, but it is currently unclear how different symptoms emerge as well as their link with cognitive deficits. To address these questions, we examined the duration of basic symptoms (BS) and attenuated psychotic symptoms (APS) in a sample of CHR-P participants to test the hypothesis that BS precede the manifestation of APS. As a secondary objective, we investigated the relationship between DUR, functioning and neuropsychological deficits. Methods Data from 134 CHR-P participants were assessed with the Comprehensive Assessment of At-Risk Mental State and the Schizophrenia Proneness Interview, Adult Version. Global, role and social functioning and neurocognition were assessed and compared to a sample of healthy controls (n = 57). Results In CHR-P participants who reported both APS and BS, onset of BS and APS was not significantly related. When divided into short and long BS duration (</> 8 years), CHR-P participants with a longer duration of BS showed evidence for an onset of BS preceding APS (n = 8, p = 0.003). However, in the short BS duration group, APS showed evidence of preceding BS (n = 56, p = 0.020). Finally, there were no significant effects of DUR on cognition or functioning measures. Conclusion The present findings do not support the view that APS constitute a secondary phenomenon to BS. Moreover, our data could also not confirm that DUR has a significant effect on functioning and cognitive deficits. These findings are discussed in the context of current theories regarding emerging psychosis and the importance of DUR.

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Faculty Opinions recommendation of Efficacy and Acceptability of Interventions for Attenuated Positive Psychotic Symptoms in Individuals at Clinical High Risk of Psychosis: A Network Meta-Analysis.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.733520235.793567538 ◽

2019 ◽

Author(s):

Vijay Mittal

Keyword(s):

High Risk ◽

Meta Analysis ◽

Psychotic Symptoms ◽

Clinical High Risk

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Meta-analyzing the prevalence and prognostic effect of antipsychotic exposure in clinical high-risk (CHR): when things are not what they seem

Psychological Medicine ◽

10.1017/s0033291720004237 ◽

2020 ◽

pp. 1-9

Author(s):

Andrea Raballo ◽

Michele Poletti ◽

Antonio Preti

Keyword(s):

High Risk ◽

Meta Analysis ◽

Prognostic Impact ◽

Clinical High Risk ◽

Qualitative Synthesis ◽

Prognostic Effect ◽

Inverse Variance ◽

Arcsine Transformation ◽

Estimate Prevalence

Abstract Background The clinical high-risk (CHR) for psychosis paradigm is changing psychiatric practice. However, a widespread confounder, i.e. baseline exposure to antipsychotics (AP) in CHR samples, is systematically overlooked. Such exposure might mitigate the initial clinical presentation, increase the heterogeneity within CHR populations, and confound the evaluation of transition to psychosis at follow-up. This is the first meta-analysis examining the prevalence and the prognostic impact on transition to psychosis of ongoing AP treatment at baseline in CHR cohorts. Methods Major databases were searched for articles published until 20 April 2020. The variance-stabilizing Freeman-Tukey double arcsine transformation was used to estimate prevalence. The binary outcome of transition to psychosis by group was estimated with risk ratio (RR) and the inverse variance method was used for pooling. Results Fourteen studies were eligible for qualitative synthesis, including 1588 CHR individuals. Out of the pooled CHR sample, 370 individuals (i.e. 23.3%) were already exposed to AP at the time of CHR status ascription. Transition toward full-blown psychosis at follow-up intervened in 112 (29%; 95% CI 24–34%) of the AP-exposed CHR as compared to 235 (16%; 14–19%) of the AP-naïve CHR participants. AP-exposed CHR had higher RR of transition to psychosis (RR = 1.47; 95% CI 1.18–1.83; z = 3.48; p = 0.0005), without influence by age, gender ratio, overall sample size, duration of the follow-up, or quality of the studies. Conclusions Baseline AP exposure in CHR samples is substantial and is associated with a higher imminent risk of transition to psychosis. Therefore, such exposure should be regarded as a non-negligible red flag for clinical risk management.

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Striatal glutamate and the conversion to psychosis: a prospective 1H-MRS imaging study

The International Journal of Neuropsychopharmacology ◽

10.1017/s1461145712000314 ◽

2012 ◽

Vol 16 (2) ◽

pp. 471-475 ◽

Cited By ~ 60

Author(s):

Camilo de la Fuente-Sandoval ◽

Pablo León-Ortiz ◽

Mariana Azcárraga ◽

Rafael Favila ◽

Sylvana Stephano ◽

...

Keyword(s):

Proton Magnetic Resonance ◽

Proton Magnetic Resonance Spectroscopy ◽

Imaging Study ◽

Psychotic Symptoms ◽

Resonance Spectroscopy ◽

Control Groups ◽

1H Mrs ◽

Ultra High Risk ◽

And Control

Abstract Increased glutamate levels in the associative-striatum have been described in subjects at ultra-high risk for psychosis (UHR); nevertheless, it is unclear whether this abnormality predicts the conversion to psychosis. Nineteen subjects at UHR and 26 controls were studied using proton magnetic resonance spectroscopy. Subjects at UHR were clinically followed for 2 yr. Seven UHR subjects (37%) transitioned to a psychotic disorder and the remaining 12 did not exhibit psychotic symptoms at the most recent follow-up. The psychosis transition group had higher glutamate levels compared to both non-transition and control groups (p = 0.02 and p < 0.01, respectively; effect size 1.39). These pilot findings suggest that the conversion to psychosis is associated with increased glutamate levels in the associative-striatum.

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What makes the psychosis ‘clinical high risk’ state risky: psychosis itself or the co-presence of a non-psychotic disorder?

Epidemiology and Psychiatric Sciences ◽

10.1017/s204579602100041x ◽

2021 ◽

Vol 30 ◽

Author(s):

Laila Hasmi ◽

Lotta-Katrin Pries ◽

Margreet ten Have ◽

Ron de Graaf ◽

Saskia van Dorsselaer ◽

...

Keyword(s):

High Risk ◽

Drug Use ◽

Psychotic Disorder ◽

Positive Family History ◽

Mental Health Service Use ◽

Psychotic Symptoms ◽

Polygenic Risk Score ◽

Clinical High Risk ◽

Drug Use Disorders ◽

Per Se

Abstract Aims Although attenuated psychotic symptoms in the psychosis clinical high-risk state (CHR-P) almost always occur in the context of a non-psychotic disorder (NPD), NPD is considered an undesired ‘comorbidity’ epiphenomenon rather than an integral part of CHR-P itself. Prospective work, however, indicates that much more of the clinical psychosis incidence is attributable to prior mood and drug use disorders than to psychosis clinical high-risk states per se. In order to examine this conundrum, we analysed to what degree the ‘risk’ in CHR-P is indexed by co-present NPD rather than attenuated psychosis per se. Methods We examined the incidence of early psychotic experiences (PE) with and without NPD (mood disorders, anxiety disorders, alcohol/drug use disorders), in a prospective general population cohort (n = 6123 at risk of incident PE at baseline). Four interview waves were conducted between 2007 and 2018 (NEMESIS-2). The incidence of PE, alone (PE-only) or with NPD (PE + NPD) was calculated, as were differential associations with schizophrenia polygenic risk score (PRS-Sz), environmental, demographical, clinical and cognitive factors. Results The incidence of PE + NPD (0.37%) was lower than the incidence of PE-only (1.04%), representing around a third of the total yearly incidence of PE. Incident PE + NPD was, in comparison with PE-only, differentially characterised by poor functioning, environmental risks, PRS-Sz, positive family history, prescription of antipsychotic medication and (mental) health service use. Conclusions The risk in ‘clinical high risk’ states is mediated not by attenuated psychosis per se but specifically the combination of attenuated psychosis and NPD. CHR-P/APS research should be reconceptualised from a focus on attenuated psychotic symptoms with exclusion of non-psychotic DSM-disorders, as the ‘pure' representation of a supposedly homotypic psychosis risk state, towards a focus on poor-outcome NPDs, characterised by a degree of psychosis admixture, on the pathway to psychotic disorder outcomes.

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