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

Author(s):  
Gemma Modinos ◽  
Anja Richter ◽  
Alice Egerton ◽  
Ilaria Bonoldi ◽  
Matilda Azis ◽  
...  

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.

Author(s):  
Gemma Modinos ◽  
Anja Richter ◽  
Alice Egerton ◽  
Ilaria Bonoldi ◽  
Matilda Azis ◽  
...  

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.


2019 ◽  
Vol 45 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Oliver D. Howes ◽  
Ilaria Bonoldi ◽  
Robert A. McCutcheon ◽  
Matilda Azis ◽  
Mathilde Antoniades ◽  
...  

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paul Allen ◽  
Emily J. Hird ◽  
Natasza Orlov ◽  
Gemma Modinos ◽  
Matthijs Bossong ◽  
...  

AbstractPreclinical rodent models suggest that psychosis involves alterations in the activity and glutamatergic function in the hippocampus, driving dopamine activity through projections to the striatum. The extent to which this model applies to the onset of psychosis in clinical subjects is unclear. We assessed whether interactions between hippocampal glutamatergic function and activity/striatal connectivity are associated with adverse clinical outcomes in people at clinical high-risk (CHR) for psychosis. We measured functional Magnetic Resonance Imaging of hippocampal activation/connectivity, and 1H-Magnetic Resonance Spectroscopy of hippocampal glutamatergic metabolites in 75 CHR participants and 31 healthy volunteers. At follow-up, 12 CHR participants had transitioned to psychosis and 63 had not. Within the clinical high-risk cohort, at follow-up, 35 and 17 participants had a poor or a good functional outcome, respectively. The onset of psychosis (ppeakFWE = 0.003, t = 4.4, z = 4.19) and a poor functional outcome (ppeakFWE < 0.001, t = 5.52, z = 4.81 and ppeakFWE < 0.001, t = 5.25, z = 4.62) were associated with a negative correlation between the hippocampal activation and hippocampal Glx concentration at baseline. In addition, there was a negative association between hippocampal Glx concentration and hippocampo-striatal connectivity (ppeakFWE = 0.016, t = 3.73, z = 3.39, ppeakFWE = 0.014, t = 3.78, z = 3.42, ppeakFWE = 0.011, t = 4.45, z = 3.91, ppeakFWE = 0.003, t = 4.92, z = 4.23) in the total CHR sample, not seen in healthy volunteers. As predicted by preclinical models, adverse clinical outcomes in people at risk for psychosis are associated with altered interactions between hippocampal activity and glutamatergic function.


2021 ◽  
Author(s):  
Paul Allen ◽  
Emily J. Hird ◽  
Natasza Orlov ◽  
Gemma Modinos ◽  
Matthijs Bossong ◽  
...  

AbstractPreclinical models suggest that psychosis involves alterations in activity and glutamate function in the hippocampus, driving dopamine activity through projections to the striatum. The extent to which this model applies to the onset of psychosis in clinical subjects is unclear. We assessed whether interactions between hippocampal glutamatergic function and activity/striatal-connectivity are associated with adverse clinical outcomes in people at clinical high-risk (CHR) for psychosis. We measured functional Magnetic Resonance Imaging of hippocampal activation/connectivity, and 1H-Magnetic Resonance Spectroscopy of hippocampal glutamatergic metabolites in 75 CHR participants and 31 healthy volunteers. At follow-up, 12 CHR participants had transitioned to psychosis and 63 had not. Within the clinical high-risk cohort, at follow-up, 35 and 17 participants had a poor or a good functional outcome, respectively. The onset of psychosis (ppeakFWE =.003, t=4.4, z=4.19) and a poor functional outcome (ppeakFWE <.001, t=5.52, z=4.81 and ppeakFWE <.001, t=5.25, z=4.62) were associated with a negative correlation between hippocampal activation and hippocampal Glx concentration at baseline. In addition, there was a negative association between hippocampal Glx concentration and hippocampo-striatal connectivity (ppeakFWE=.016, t=3.73, z=3.39, ppeakFWE=.014, t=3.78, z=3.42, ppeakFWE=.011, t=4.45, z=3.91, ppeakFWE=.003, t=4.92, z=4.23) in the total CHR sample, not seen in healthy volunteers. As predicted by preclinical models, adverse clinical outcomes in people at risk for psychosis are associated with altered interactions between hippocampal activity and glutamatergic function.


2016 ◽  
Vol 26 (3) ◽  
pp. 287-298 ◽  
Author(s):  
T. H. Zhang ◽  
H. J. Li ◽  
K. A. Woodberry ◽  
L. H. Xu ◽  
Y. Y. Tang ◽  
...  

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.


2020 ◽  
pp. 1-9
Author(s):  
Ana Catalan ◽  
Stefania Tognin ◽  
Matthew J. Kempton ◽  
Daniel Stahl ◽  
Gonzalo Salazar de Pablo ◽  
...  

Abstract Background Psychosis is associated with a reasoning bias, which manifests as a tendency to ‘jump to conclusions’. We examined this bias in people at clinical high-risk for psychosis (CHR) and investigated its relationship with their clinical outcomes. Methods In total, 303 CHR subjects and 57 healthy controls (HC) were included. Both groups were assessed at baseline, and after 1 and 2 years. A ‘beads’ task was used to assess reasoning bias. Symptoms and level of functioning were assessed using the Comprehensive Assessment of At-Risk Mental States scale (CAARMS) and the Global Assessment of Functioning (GAF), respectively. During follow up, 58 (16.1%) of the CHR group developed psychosis (CHR-T), and 245 did not (CHR-NT). Logistic regressions, multilevel mixed models, and Cox regression were used to analyse the relationship between reasoning bias and transition to psychosis and level of functioning, at each time point. Results There was no association between reasoning bias at baseline and the subsequent onset of psychosis. However, when assessed after the transition to psychosis, CHR-T participants showed a greater tendency to jump to conclusions than CHR-NT and HC participants (55, 17, 17%; χ2 = 8.13, p = 0.012). There was a significant association between jumping to conclusions (JTC) at baseline and a reduced level of functioning at 2-year follow-up in the CHR group after adjusting for transition, gender, ethnicity, age, and IQ. Conclusions In CHR participants, JTC at baseline was associated with adverse functioning at the follow-up. Interventions designed to improve JTC could be beneficial in the CHR population.


2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S57-S58
Author(s):  
Kate Haining ◽  
Gina Brunner ◽  
Ruchika Gajwani ◽  
Joachim Gross ◽  
Andrew Gumley ◽  
...  

Abstract Background Research in individuals at clinical-high risk for psychosis (CHR-P) has focused on developing algorithms to predict transition to psychosis. However, it is becoming increasingly important to address other outcomes, such as the level of functioning of CHR-P participants. To address this important question, this study investigated the relationship between baseline cognitive performance and functional outcome between 6–12 months in a sample of CHR-P individuals using a machine-learning approach to identify features that are predictive of long-term functional impairments. Methods Data was available for 111 CHR-P individuals at 6–12 months follow-up. In addition, 47 CHR-negative (CHR-N) participants who did not meet CHR criteria and 55 healthy controls (HCs) were recruited. CHR-P status was assessed using the Comprehensive Assessment of At-Risk Mental States (CAARMS) and the Schizophrenia Proneness Instrument, Adult version (SPI-A). Cognitive assessments included the Brief Assessment of Cognition in Schizophrenia (BACS) and the Penn Computerized Neurocognitive Battery (CNB). Global, social and role functioning scales were used to measure functional status. CHR-P individuals were divided into good functional outcome (GFO, GAF ≥ 65) and poor functional outcome groups (PFO, GAF &lt; 65). Feature selection was performed using LASSO regression with the LARS algorithm and 10-fold cross validation with GAF scores at baseline as the outcome variable. The following features were identified as predictors of GAF scores at baseline: verbal memory, verbal fluency, attention, emotion recognition, social and role functioning and SPI-A distress. This model explained 47% of the variance in baseline GAF scores. In the next step, Support Vector Machines (SVM), Linear Discriminant Analysis (LDA), Logistic Regression (LR), Gaussian Naïve Bayes (GNB), and Random Forest (RF) classifiers with 10-fold cross validation were then trained on those features with GAF category at follow-up used as the binary label column. Models were compared using a calculated score incorporating area under the curve (AUC), accuracy, and AUC consistency across runs, whereby AUC was given a higher weighting than accuracy due to class imbalance. Results CHR-P individuals had slower motor speed, reduced attention and processing speed and increased emotion recognition reaction times (RTs) compared to HCs and reduced attention and processing speed compared to CHR-Ns. At follow-up, 66% of CHR-P individuals had PFO. LDA emerged as the strongest classifier, showing a mean AUC of 0.75 (SD = 0.15), indicating acceptable classification performance for GAF category at follow-up. PFO was detected with a sensitivity of 75% and specificity of 58%, with a total mean weighted accuracy of 68%. Discussion The CHR-P state was associated with significant impairments in cognition, highlighting the importance of interventions such as cognitive remediation in this population. Our data suggest that the development of features using machine learning approaches is effective in predicting functional outcomes in CHR-P individuals. Greater levels of accuracy, sensitivity and specificity might be achieved by increasing training sets and validating the classifier with external data sets. Indeed, machine learning methods have potential given that trained classifiers can easily be shared online, thus enabling clinical professionals to make individualised predictions.


2017 ◽  
Vol 7 (10) ◽  
pp. e1245-e1245 ◽  
Author(s):  
T Winton-Brown ◽  
A Schmidt ◽  
J P Roiser ◽  
O D Howes ◽  
A Egerton ◽  
...  

Abstract Animal models of psychosis propose that abnormal hippocampal activity drives increased subcortical dopamine function, which is thought to contribute to aberrant salience processing and psychotic symptoms. These effects appear to be mediated through connections between the hippocampus, ventral striatum/pallidum and the midbrain. The aim of the present study was to examine the activity and connectivity in this pathway in people at ultra high risk (UHR) for psychosis. Functional magnetic resonance imaging was used to compare neural responses in a hippocampal–basal ganglia–midbrain network during reward, novelty and aversion processing between 29 UHR subjects and 32 healthy controls. We then investigated whether effective connectivity within this network is perturbed in UHR subjects, using dynamic causal modelling (DCM). Finally, we examined the relationship between alterations in activation and connectivity in the UHR subjects and the severity of their psychotic symptoms. During reward anticipation, UHR subjects showed greater activation than controls in the ventral pallidum bilaterally. There were no differences in activation during novelty or aversion processing. DCM revealed that reward-induced modulation of connectivity from the ventral striatum/pallidum to the midbrain was greater in UHR subjects than controls, and that in UHR subjects, the strength of connectivity in this pathway was correlated with the severity of their abnormal beliefs. In conclusion, ventral striatal/pallidal function is altered in people at UHR for psychosis and this is related to the level of their psychotic symptoms.


Author(s):  
Kate Haining ◽  
Ruchika Gajwani ◽  
Joachim Gross ◽  
Andrew I. Gumley ◽  
Robin A. A. Ince ◽  
...  

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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lorna Staines ◽  
Ruchika Gajwani ◽  
Joachim Gross ◽  
Andrew I. Gumley ◽  
Stephen M. Lawrie ◽  
...  

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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