ABSTRACT
Dopaminergic dysregulation is one of the leading hypotheses for the pathoetiology underlying psychotic disorders such as schizophrenia. Molecular imaging studies have shown increased striatal dopamine synthesis capacity (DSC) in schizophrenia and people in the prodrome of psychosis. However, it is unclear if genetic risk for psychosis is associated with altered DSC. To investigate this, we recruited healthy controls and two antipsychotic naive groups of individuals with copy number variants, one with a genetic deletion at chromosome 22q11.2, and the other with a duplication at the same locus, who are at increased and decreased risk for psychosis, respectively. Fifty-nine individuals (21 with 22q11.2 deletion, 12 with the reciprocal duplication and 26 healthy controls) received clinical measures and [18F]-DOPA PET imaging to index striatal Kicer. There was an inverse linear effect of copy number variant number on striatal Kicer value (B = -1.2 × 10-3, SE = 2 × 10-4, p < 0.001), with controls showing levels intermediate between the two variant groups. Striatal Kicer was significantly higher in the 22q11.2 deletion group compared to the healthy control (p < 0.001, Cohen's d = 1.44) and 22q11.2 duplication (p < 0.001, Cohen's d = 2) groups. Moreover, Kicer was positively correlated with the severity of psychosis-risk symptoms (B = 730.5, SE = 310.2, p < 0.05) and increased over time in the subject who went on to develop psychosis, but was not associated with anxiety or depressive symptoms. Our findings suggest that genetic risk for psychosis is associated with dopaminergic dysfunction and identify dopamine synthesis as a potential target for treatment or prevention of psychosis in 22q11.2 deletion carriers.
Subject(s)
DiGeorge Syndrome , Psychotic Disorders , Humans , Dopamine , DNA Copy Number Variations/genetics , Psychotic Disorders/diagnostic imaging , Psychotic Disorders/genetics , Dihydroxyphenylalanine , DiGeorge Syndrome/diagnostic imaging , DiGeorge Syndrome/genetics , Positron-Emission Tomography/methodsABSTRACT
Informal caregivers of individuals affected by psychotic disorder can play a key role in the recovery process. However, little research has been conducted on the lived experiences of carers and family members. We conducted a bottom-up (from lived experience to theory) review of first-person accounts, co-written between academics and experts by experience, to identify key experiential themes. First-person accounts of carers, relatives, and individuals with psychosis were screened and discussed in collaborative workshops involving individuals with lived experiences of psychosis, family members, and carers, representing various organizations. The lived experiences of family members and carers were characterized by experiential themes related to dealing with the unexpected news, the search for a reason behind the disorder, living with difficult and negative emotions, dealing with loss, feeling lost in fragmented healthcare systems, feeling invisible and wanting to be active partners in care, struggling to communicate with the affected person, fighting stigma and isolation, dealing with an uncertain future, and learning from one's mistakes and building resilience and hope. Our findings bring forth the voices of relatives and informal carers of people with psychosis, by highlighting some of the common themes of their lived experiences from the time of the initial diagnosis and throughout the different clinical stages of the disorder. Informal carers are key stakeholders who can play a strategic role, and their contributions in the recovery process merit recognition and active support by mental health professionals.
Subject(s)
Caregivers , Psychotic Disorders , Humans , Caregivers/psychology , Psychotic Disorders/psychology , Family/psychologyABSTRACT
A leading hypothesis for schizophrenia and related psychotic disorders proposes that cortical brain disruption leads to subcortical dopaminergic dysfunction, which underlies psychosis in the majority of patients who respond to treatment. Although supported by preclinical findings that prefrontal cortical lesions lead to striatal dopamine dysregulation, the relationship between prefrontal structural volume and striatal dopamine function has not been tested in people with psychosis. We therefore investigated the in vivo relationship between striatal dopamine synthesis capacity and prefrontal grey matter volume in treatment-responsive patients with psychosis, and compared them to treatment non-responsive patients, where dopaminergic mechanisms are not thought to be central. Forty patients with psychosis across two independent cohorts underwent 18F-DOPA PET scans to measure dopamine synthesis capacity (indexed as the influx rate constant Kicer) and structural 3T MRI. The PET, but not MR, data have been reported previously. Structural images were processed using DARTEL-VBM. GLM analyses were performed in SPM12 to test the relationship between prefrontal grey matter volume and striatal Kicer. Treatment responders showed a negative correlation between prefrontal grey matter and striatal dopamine synthesis capacity, but this was not evident in treatment non-responders. Specifically, we found an interaction between treatment response, whole striatal dopamine synthesis capacity and grey matter volume in left (pFWE corr. = 0.017) and right (pFWE corr. = 0.042) prefrontal cortex. We replicated the finding in right prefrontal cortex in the independent sample (pFWE corr. = 0.031). The summary effect size was 0.82. Our findings are consistent with the long-standing hypothesis of dysregulation of the striatal dopaminergic system being related to prefrontal cortex pathology in schizophrenia, but critically also extend the hypothesis to indicate it can be applied to treatment-responsive schizophrenia only. This suggests that different mechanisms underlie the pathophysiology of treatment-responsive and treatment-resistant schizophrenia.
Subject(s)
Dopamine , Psychotic Disorders , Dihydroxyphenylalanine/analogs & derivatives , Gray Matter/diagnostic imaging , Humans , Magnetic Resonance Imaging , Positron-Emission Tomography , Psychotic Disorders/diagnostic imagingABSTRACT
The ability to identify biomarkers of psychosis risk is essential in defining effective preventive measures to potentially circumvent the transition to psychosis. Using samples of people at clinical high risk for psychosis (CHR) and Healthy controls (HC) who were administered a task fMRI paradigm, we used a framework for labelling time windows of fMRI scans as 'integrated' FC networks to provide a granular representation of functional connectivity (FC). Periods of integration were defined using the 'cartographic profile' of time windows and k-means clustering, and sub-network discovery was carried out using Network Based Statistics (NBS). There were no network differences between CHR and HC groups. Within the CHR group, using integrated FC networks, we identified a sub-network negatively associated with longitudinal changes in the severity of psychotic symptoms. This sub-network comprised brain areas implicated in bottom-up sensory processing and in integration with motor control, suggesting it may be related to the demands of the fMRI task. These data suggest that extracting integrated FC networks may be useful in the investigation of biomarkers of psychosis risk.
Subject(s)
Brain/diagnostic imaging , Magnetic Resonance Imaging/methods , Nerve Net/diagnostic imaging , Prodromal Symptoms , Psychotic Disorders/diagnostic imaging , Adolescent , Adult , Brain/physiology , Connectome/methods , Female , Humans , Longitudinal Studies , Male , Nerve Net/physiology , Predictive Value of Tests , Psychomotor Performance/physiology , Psychotic Disorders/psychology , Risk Factors , Young AdultABSTRACT
BACKGROUND: The clinical high-risk state for psychosis (CHR-P) paradigm has facilitated the implementation of psychosis prevention into clinical practice; however, advancements in adolescent CHR-P populations are less established. METHODS: We performed a PRISMA/MOOSE-compliant systematic review of the Web of Science database, from inception until 7 October 2019, to identify original studies conducted in CHR-P children and adolescents (mean age <18 years). Findings were systematically appraised around core themes: detection, prognosis and intervention. We performed meta-analyses (employing Q statistics and I 2 test) regarding the proportion of CHR-P subgroups, the prevalence of baseline comorbid mental disorders, the risk of psychosis onset and the type of interventions received at baseline. Quality assessment and publication bias were also analysed. RESULTS: Eighty-seven articles were included (n = 4,667 CHR-P individuals). Quality of studies ranged from 3.5 to 8 (median 5.5) on a modified Newcastle-Ottawa scale. Detection: Individuals were aged 15.6 ± 1.2 years (51.5% males), mostly (83%) presenting with attenuated positive psychotic symptoms. CHR-P psychometric accuracy improved when caregivers served as additional informants. Comorbid mood (46.4%) and anxiety (31.4%) disorders were highly prevalent. Functioning and cognition were impaired. Neurobiological studies were inconclusive. PROGNOSIS: Risk for psychosis was 10.4% (95%CI: 5.8%-18.1%) at 6 months, 20% (95%CI: 15%-26%) at 12 months, 23% (95%CI: 18%-29%) at 24 months and 23.3% (95%CI: 17.3%-30.7%) at ≥36 months. INTERVENTIONS: There was not enough evidence to recommend one specific treatment (including cognitive behavioural therapy) over the others (including control conditions) to prevent the transition to psychosis in this population. Randomised controlled trials suggested that family interventions, cognitive remediation and fish oil supplementation may improve cognition, symptoms and functioning. At baseline, 30% of CHR-P adolescents were prescribed antipsychotics and 60% received psychotherapy. CONCLUSIONS: It is possible to detect and formulate a group-level prognosis in adolescents at risk for psychosis. Future interventional research is required.
Subject(s)
Antipsychotic Agents , Cognitive Remediation , Psychotic Disorders , Adolescent , Anxiety Disorders , Female , Humans , Male , Prognosis , Psychotic Disorders/diagnosis , Psychotic Disorders/epidemiology , Psychotic Disorders/prevention & controlABSTRACT
Whilst the role of the Disrupted-in-Schizophrenia 1 (DISC1) gene in the aetiology of major mental illnesses is debated, the characterization of its function lends it credibility as a candidate. A key aspect of this functional characterization is the determination of the role of common non-synonymous polymorphisms on normal variation within these functions. The common allele (A) of the DISC1 single-nucleotide polymorphism (SNP) rs821616 encodes a serine (ser) at the Ser704Cys polymorphism, and has been shown to increase the phosphorylation of extracellular signal-regulated protein Kinases 1 and 2 (ERK1/2) that stimulate the phosphorylation of tyrosine hydroxylase, the rate-limiting enzyme for dopamine biosynthesis. We therefore set out to test the hypothesis that human ser (A) homozygotes would show elevated dopamine synthesis capacity compared with cysteine (cys) homozygotes and heterozygotes (TT and AT) for rs821616. [18F]-DOPA positron emission tomography (PET) was used to index striatal dopamine synthesis capacity as the influx rate constant Kicer in healthy volunteers DISC1 rs821616 ser homozygotes (N = 46) and healthy volunteers DISC1 rs821616 cys homozygotes and heterozygotes (N = 56), matched for age, gender, ethnicity and using three scanners. We found DISC1 rs821616 ser homozygotes exhibited a significantly higher striatal Kicer compared with cys homozygotes and heterozygotes (P = 0.012) explaining 6.4% of the variance (partial η2 = 0.064). Our finding is consistent with its previous association with heightened activation of ERK1/2, which stimulates tyrosine hydroxylase activity for dopamine synthesis. This could be a potential mechanism mediating risk for psychosis, lending further credibility to the fact that DISC1 is of functional interest in the aetiology of major mental illness.
Subject(s)
Corpus Striatum/metabolism , Dopamine/biosynthesis , Genetic Predisposition to Disease , Nerve Tissue Proteins/genetics , Polymorphism, Single Nucleotide , Schizophrenia/genetics , Adult , Corpus Striatum/diagnostic imaging , Dihydroxyphenylalanine/analogs & derivatives , Female , Humans , MAP Kinase Signaling System , Male , Nerve Tissue Proteins/metabolism , Positron-Emission Tomography , Psychotic Disorders/genetics , Psychotic Disorders/metabolism , Schizophrenia/diagnostic imaging , Schizophrenia/metabolism , Young AdultABSTRACT
Background: Whilst robust preclinical and postmortem evidence suggests that altered GABAergic function is central to the development of psychosis, little is known about whether it is altered in subjects at ultra-high risk of psychosis, or its relationship to prodromal symptoms. Methods: Twenty-one antipsychotic naïve ultra-high risk individuals and 20 healthy volunteers underwent proton magnetic resonance imaging at 3T. Gamma-aminobutyric acid levels were obtained from the medial prefrontal cortex using MEGA-PRESS and expressed as peak-area ratios relative to the synchronously acquired creatine signal. Gamma-aminobutyric acid levels were then related to severity of positive and negative symptoms as measured with the Community Assessment of At-Risk Mental States. Results: Whilst we found no significant difference in gamma-aminobutyric acid levels between ultra-high risk subjects and healthy controls (P=.130), in ultra-high risk individuals, medial prefrontal cortex GABA levels were negatively correlated with the severity of negative symptoms (P=.013). Conclusion: These findings suggest that gamma-aminobutyric acidergic neurotransmission may be involved in the neurobiology of negative symptoms in the ultra-high risk state.
Subject(s)
Prefrontal Cortex/metabolism , Prodromal Symptoms , Proton Magnetic Resonance Spectroscopy/methods , Psychotic Disorders/metabolism , Psychotic Disorders/physiopathology , gamma-Aminobutyric Acid/metabolism , Adolescent , Adult , Humans , Male , Prefrontal Cortex/diagnostic imaging , Psychotic Disorders/diagnostic imaging , Risk , Severity of Illness Index , Young AdultABSTRACT
BACKGROUND: Contemporary phenomenological research has considered abnormal bodily phenomena (ABP) to be a phenotypic trait of subjects with schizophrenia in their first psychotic episode. Yet the prevalence of ABP and their clinical significance in subjects at Ultra High Risk (UHR) of psychosis remain unidentified. This study is an exploratory investigation of ABP in UHR subjects and matched healthy controls (HCs) examining their relation to clinical features and basic self-disturbances. METHODS: A sample of 26 UHR and 14 HC subjects from three prodromal and early intervention clinics in South London, West London and Cambridge was assessed with the Abnormal Bodily Phenomena questionnaire (ABPq), Comprehensive Assessment of At-Risk Mental States (CAARMS), the Positive and Negative Syndrome Scale (PANSS), the Social and Occupational Functioning Assessment Scale (SOFAS) and the Examination of Anomalous Self Experiences (EASE) checklist. RESULTS: In our sample ABP occurred in 73.1% of UHR subjects and prominent ABP (proABP) were referred in 53.8% of them. No HC subject reported ABP. The UHR group with proABP had lower CAARMS total score (t=-9.265, p=0.006). There were no differences in PANSS total score (t=-1.235, p=0.277), SOFAS score (H(2) 22.27, p=0.666) and EASE total scores (z=8.565, adjusted p=0.185) in the UHR subjects with prominent ABP versus those that did not. DISCUSSION: This initial investigation suggests that ABP could be a prevalent phenotypic feature of UHR subjects.
Subject(s)
Hallucinations/diagnosis , Hallucinations/epidemiology , Psychotic Disorders/diagnosis , Psychotic Disorders/epidemiology , Adolescent , Adult , Female , Follow-Up Studies , Hallucinations/psychology , Humans , London/epidemiology , Male , Prevalence , Psychotic Disorders/psychology , Risk Assessment/methods , Risk Factors , Single-Blind Method , Surveys and Questionnaires , Young AdultABSTRACT
We provide here the first bottom-up review of the lived experience of mental disorders in adolescents co-designed, co-conducted and co-written by experts by experience and academics. We screened first-person accounts within and outside the medical field, and discussed them in collaborative workshops involving numerous experts by experience - representing different genders, ethnic and cultural backgrounds, and continents - and their family members and carers. Subsequently, the material was enriched by phenomenologically informed perspectives and shared with all collaborators. The inner subjective experience of adolescents is described for mood disorders, psychotic disorders, attention-deficit/hyperactivity disorder, autism spectrum disorders, anxiety disorders, eating disorders, externalizing disorders, and self-harm behaviors. The recollection of individuals' past histories also indexes the prodromal (often transdiagnostic) features predating the psychiatric diagnosis. The experience of adolescents with mental disorders in the wider society is described with respect to their family, their school and peers, and the social and cultural context. Furthermore, their lived experience of mental health care is described with respect to receiving a diagnosis of mental disorder, accessing mental health support, receiving psychopharmacological treatment, receiving psychotherapy, experiencing peer support and mental health activism, and achieving recovery. These findings can impact clinical practice, research, and the whole society. We hope that this co-designed, co-conducted and co-written journey can help us maintain our commitment to protecting adolescents' fragile mental health, and can help them develop into a healthy, fulfilling and contributing adult life.
ABSTRACT
We provide here the first bottom-up review of the lived experience of depression, co-written by experts by experience and academics. First-person accounts within and outside the medical field were screened and discussed in collaborative workshops involving numerous individuals with lived experience of depression, family members and carers, representing a global network of organizations. The material was enriched by phenomenologically informed perspectives and shared with all collaborators in a cloud-based system. The subjective world of depression was characterized by an altered experience of emotions and body (feeling overwhelmed by negative emotions, unable to experience positive emotions, stuck in a heavy aching body drained of energy, detached from the mind, the body and the world); an altered experience of the self (losing sense of purpose and existential hope, mismatch between the past and the depressed self, feeling painfully incarcerated, losing control over one's thoughts, losing the capacity to act on the world; feeling numb, empty, non-existent, dead, and dreaming of death as a possible escape route); and an altered experience of time (experiencing an alteration of vital biorhythms, an overwhelming past, a stagnation of the present, and the impossibility of the future). The experience of depression in the social and cultural context was characterized by altered interpersonal experiences (struggling with communication, feeling loneliness and estrangement, perceiving stigma and stereotypes), and varied across different cultures, ethnic or racial minorities, and genders. The subjective perception of recovery varied (feeling contrasting attitudes towards recovery, recognizing recovery as a journey, recognizing one's vulnerability and the need for professional help), as did the experience of receiving pharmacotherapy, psychotherapy, and social as well as physical health interventions. These findings can inform clinical practice, research and education. This journey in the lived experience of depression can also help us to understand the nature of our own emotions and feelings, what is to believe in something, what is to hope, and what is to be a living human being.
ABSTRACT
In this study we evaluate the performance of a fully automated analytical framework for FDOPA PET neuroimaging data, and its sensitivity to demographic and experimental variables and processing parameters. An instance of XNAT imaging platform was used to store the King's College London institutional brain FDOPA PET imaging archive, alongside individual demographics and clinical information. By re-engineering the historical Matlab-based scripts for FDOPA PET analysis, a fully automated analysis pipeline for imaging processing and data quantification was implemented in Python and integrated in XNAT. The final data repository includes 892 FDOPA PET scans organized from 23 different studies. We found good reproducibility of the data analysis by the automated pipeline (in the striatum for the Kicer: for the controls ICC = 0.71, for the psychotic patients ICC = 0.88). From the demographic and experimental variables assessed, gender was found to most influence striatal dopamine synthesis capacity (F = 10.7, p < 0.001), with women showing greater dopamine synthesis capacity than men. Our automated analysis pipeline represents a valid resourse for standardised and robust quantification of dopamine synthesis capacity using FDOPA PET data. Combining information from different neuroimaging studies has allowed us to test it comprehensively and to validate its replicability and reproducibility performances on a large sample size.
Subject(s)
Dihydroxyphenylalanine , Dopamine , Male , Humans , Female , Dopamine/metabolism , Reproducibility of Results , Positron-Emission Tomography/methods , NeuroimagingABSTRACT
The D2 dopamine receptor (D2R) is the primary site of the therapeutic action of antipsychotics and is involved in essential brain functions relevant to schizophrenia, such as attention, memory, motivation, and emotion processing. Moreover, the gene coding for D2R (DRD2) has been associated with schizophrenia at a genome-wide level. Recent studies have shown that a polygenic co-expression index (PCI) predicting the brain-specific expression of a network of genes co-expressed with DRD2 was associated with response to antipsychotics, brain function during working memory in patients with schizophrenia, and with the modulation of prefrontal cortex activity after pharmacological stimulation of D2 receptors. We aimed to investigate the relationship between the DRD2 gene network and in vivo striatal dopaminergic function, which is a phenotype robustly associated with psychosis and schizophrenia. To this aim, a sample of 92 healthy subjects underwent 18F-DOPA PET and was genotyped for genetic variations indexing the co-expression of the DRD2-related genetic network in order to calculate the PCI for each subject. The PCI was significantly associated with whole striatal dopamine synthesis capacity (p = 0.038). Exploratory analyses on the striatal subdivisions revealed a numerically larger effect size of the PCI on dopamine function for the associative striatum, although this was not significantly different than effects in other sub-divisions. These results are in line with a possible relationship between the DRD2-related co-expression network and schizophrenia and extend it by identifying a potential mechanism involving the regulation of dopamine synthesis. Future studies are needed to clarify the molecular mechanisms implicated in this relationship.
Subject(s)
Antipsychotic Agents , Dopamine , Antipsychotic Agents/metabolism , Corpus Striatum/metabolism , Dopamine/metabolism , Gene Regulatory Networks , Humans , Multifactorial Inheritance , Polymorphism, Single Nucleotide , Receptors, Dopamine D2/genetics , Receptors, Dopamine D2/metabolismABSTRACT
Psychosis is the most ineffable experience of mental disorder. We provide here the first co-written bottom-up review of the lived experience of psychosis, whereby experts by experience primarily selected the subjective themes, that were subsequently enriched by phenomenologically-informed perspectives. First-person accounts within and outside the medical field were screened and discussed in collaborative workshops involving numerous individuals with lived experience of psychosis as well as family members and carers, representing a global network of organizations. The material was complemented by semantic analyses and shared across all collaborators in a cloud-based system. The early phases of psychosis (i.e., premorbid and prodromal stages) were found to be characterized by core existential themes including loss of common sense, perplexity and lack of immersion in the world with compromised vital contact with reality, heightened salience and a feeling that something important is about to happen, perturbation of the sense of self, and need to hide the tumultuous inner experiences. The first episode stage was found to be denoted by some transitory relief associated with the onset of delusions, intense self-referentiality and permeated self-world boundaries, tumultuous internal noise, and dissolution of the sense of self with social withdrawal. Core lived experiences of the later stages (i.e., relapsing and chronic) involved grieving personal losses, feeling split, and struggling to accept the constant inner chaos, the new self, the diagnosis and an uncertain future. The experience of receiving psychiatric treatments, such as inpatient and outpatient care, social interventions, psychological treatments and medications, included both positive and negative aspects, and was determined by the hope of achieving recovery, understood as an enduring journey of reconstructing the sense of personhood and re-establishing the lost bonds with others towards meaningful goals. These findings can inform clinical practice, research and education. Psychosis is one of the most painful and upsetting existential experiences, so dizzyingly alien to our usual patterns of life and so unspeakably enigmatic and human.
ABSTRACT
INTRODUCTION: With biomedical imaging research increasingly using large datasets, it becomes critical to find operator-free methods to quality control the data collected and the associated analysis. Attempts to use artificial intelligence (AI) to perform automated quality control (QC) for both single-site and multi-site datasets have been explored in some neuroimaging techniques (e.g. EEG or MRI), although these methods struggle to find replication in other domains. The aim of this study is to test the feasibility of an automated QC pipeline for brain [18F]-FDOPA PET imaging as a biomarker for the dopamine system. METHODS: Two different Convolutional Neural Networks (CNNs) were used and combined to assess spatial misalignment to a standard template and the signal-to-noise ratio (SNR) relative to 200 static [18F]-FDOPA PET images that had been manually quality controlled from three different PET/CT scanners. The scans were combined with an additional 400 scans, in which misalignment (200 scans) and low SNR (200 scans) were simulated. A cross-validation was performed, where 80% of the data were used for training and 20% for validation. Two additional datasets of [18F]-FDOPA PET images (50 and 100 scans respectively with at least 80% of good quality images) were used for out-of-sample validation. RESULTS: The CNN performance was excellent in the training dataset (accuracy for motion: 0.86 ± 0.01, accuracy for SNR: 0.69 ± 0.01), leading to 100% accurate QC classification when applied to the two out-of-sample datasets. Data dimensionality reduction affected the generalizability of the CNNs, especially when the classifiers were applied to the out-of-sample data from 3D to 1D datasets. CONCLUSIONS: This feasibility study shows that it is possible to perform automatic QC of [18F]-FDOPA PET imaging with CNNs. The approach has the potential to be extended to other PET tracers in both brain and non-brain applications, but it is dependent on the availability of large datasets necessary for the algorithm training.
Subject(s)
Deep Learning , Artificial Intelligence , Brain/diagnostic imaging , Humans , Positron Emission Tomography Computed Tomography , Positron-Emission Tomography , Quality ControlABSTRACT
Preclinical 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.
Subject(s)
Dopamine , Psychotic Disorders , Corpus Striatum/diagnostic imaging , Hippocampus/diagnostic imaging , Humans , Magnetic Resonance Imaging , Psychotic Disorders/diagnostic imagingABSTRACT
Importance: Estimating the current likelihood of transitioning from a clinical high risk for psychosis (CHR-P) to psychosis holds paramount importance for preventive care and applied research. Objective: To quantitatively examine the consistency and magnitude of transition risk to psychosis in individuals at CHR-P. Data Sources: PubMed and Web of Science databases until November 1, 2020. Manual search of references from previous articles. Study Selection: Longitudinal studies reporting transition risks in individuals at CHR-P. Data Extraction and Synthesis: Meta-analysis compliant with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines; independent data extraction, manually and through digitalization of Kaplan-Meier curves. Main Outcome and Measures: Primary effect size was cumulative risk of transition to psychosis at 0.5, 1, 1.5, 2, 2.5, 3, 4, and more than 4 years' follow-up, estimated using the numbers of individuals at CHR-P transitioning to psychosis at each time point. These analyses were complemented by meta-analytical Kaplan-Meier curves and speed of transition to psychosis (hazard rate). Random-effects meta-analysis, between-study heterogeneity analysis, study quality assessment, and meta-regressions were conducted. Results: A total of 130 studies and 9222 individuals at CHR-P were included. The mean (SD) age was 20.3 (4.4) years, and 5100 individuals (55.3%) were male. The cumulative transition risk was 0.09 (95% CI, 0.07-0.10; k = 37; n = 6485) at 0.5 years, 0.15 (95% CI, 0.13-0.16; k = 53; n = 7907) at 1 year, 0.20 (95% CI, 0.17-0.22; k = 30; n = 5488) at 1.5 years, 0.19 (95% CI, 0.17-0.22; k = 44; n = 7351) at 2 years, 0.25 (95% CI, 0.21-0.29; k = 19; n = 3114) at 2.5 years, 0.25 (95% CI, 0.22-0.29; k = 29; n = 4029) at 3 years, 0.27 (95% CI, 0.23-0.30; k = 16; n = 2926) at 4 years, and 0.28 (95% CI, 0.20-0.37; k = 14; n = 2301) at more than 4 years. The cumulative Kaplan-Meier transition risk was 0.08 (95% CI, 0.08-0.09; n = 4860) at 0.5 years, 0.14 (95% CI, 0.13-0.15; n = 3408) at 1 year, 0.17 (95% CI, 0.16-0.19; n = 2892) at 1.5 years, 0.20 (95% CI, 0.19-0.21; n = 2357) at 2 years, 0.25 (95% CI, 0.23-0.26; n = 1444) at 2.5 years, 0.27 (95% CI, 0.25-0.28; n = 1029) at 3 years, 0.28 (95% CI, 0.26-0.29; n = 808) at 3.5 years, 0.29 (95% CI, 0.27-0.30; n = 737) at 4 years, and 0.35 (95% CI, 0.32-0.38; n = 114) at 10 years. The hazard rate only plateaued at 4 years' follow-up. Meta-regressions showed that a lower proportion of female individuals (ß = -0.02; 95% CI, -0.04 to -0.01) and a higher proportion of brief limited intermittent psychotic symptoms (ß = 0.02; 95% CI, 0.01-0.03) were associated with an increase in transition risk. Heterogeneity across the studies was high (I2 range, 77.91% to 95.73%). Conclusions and Relevance: In this meta-analysis, 25% of individuals at CHR-P developed psychosis within 3 years. Transition risk continued increasing in the long term. Extended clinical monitoring and preventive care may be beneficial in this patient population.
Subject(s)
Disease Progression , Disease Susceptibility , Psychotic Disorders/epidemiology , Risk Assessment , Adolescent , Adult , Female , Humans , Longitudinal Studies , Male , Probability , Young AdultABSTRACT
BACKGROUND: Much is not known about the efficacy of interventions to prevent poor mental health outcomes in young people by targeting either the general population (universal prevention) or asymptomatic individuals with high risk of developing a mental disorder (selective prevention). METHODS: We conducted a PRISMA/MOOSE-compliant systematic review and meta-analysis of Web of Science to identify studies comparing post-test efficacy (effect size [ES]; Hedges' g) of universal or selective interventions for poor mental health outcomes versus control groups, in samples with mean age <35 years (PROSPERO: CRD42018102143). Measurements included random-effects models, I2 statistics, publication bias, meta-regression, sensitivity analyses, quality assessments, number needed to treat, and population impact number. RESULTS: 295 articles (447,206 individuals; mean age = 15.4) appraising 17 poor mental health outcomes were included. Compared to control conditions, universal and selective interventions improved (in descending magnitude order) interpersonal violence, general psychological distress, alcohol use, anxiety features, affective symptoms, other emotional and behavioral problems, consequences of alcohol use, posttraumatic stress disorder features, conduct problems, tobacco use, externalizing behaviors, attention-deficit/hyperactivity disorder features, and cannabis use, but not eating-related problems, impaired functioning, internalizing behavior, or sleep-related problems. Psychoeducation had the highest effect size for ADHD features, affective symptoms, and interpersonal violence. Psychotherapy had the highest effect size for anxiety features. CONCLUSION: Universal and selective preventive interventions for young individuals are feasible and can improve poor mental health outcomes.
Subject(s)
Psychotherapy , Stress Disorders, Post-Traumatic , Adolescent , Anxiety , Anxiety Disorders , Humans , Outcome Assessment, Health CareABSTRACT
BACKGROUND: People with autistic spectrum disorder (ASD) are affected by a long-life disabling condition, characterized by communication deficits, severe impairments in social functioning, and stereotyped behaviors. Although ASD individuals display several problems in interactions, it has been reported that they may show a peculiar interest in music. Previous studies have suggested a pivotal role for the dopaminergic system in the psychobiology of reward, including the pleasure of music. DESIGN: In the present study, we sought to investigate dopamine DRD3 and DRD4 receptor expression in peripheral blood lymphocytes of adult healthy musicians and age- and gender-matched patients with ASD against the background hypothesis that the dopaminergic system may contribute a biological cause to the reward dimensions of the musical experience in both healthy and autistic individuals. RESULTS: ANOVA showed significant differences in DRD4 mRNA expression between the groups (P = 0.008). Post-hoc analysis showed significant differences between the control group and both musicians (P < 0.05) and ASD individuals (P < 0.05). No differences were found for DRD3 mRNA expression between the groups. CONCLUSION: Our current results provide intriguing preliminary evidence for a possible molecular link between dopamine DRD4 receptor, music and autism, possibly via mechanisms involving the reward system and the appraisal of emotions.
Subject(s)
Autistic Disorder/genetics , Lymphocytes/metabolism , Music , Receptors, Dopamine D4/genetics , Adolescent , Adult , Autistic Disorder/blood , Autistic Disorder/metabolism , Case-Control Studies , Emotions/physiology , Female , Humans , Male , RNA, Messenger/metabolism , Receptors, Dopamine D3/genetics , Receptors, Dopamine D3/metabolism , Receptors, Dopamine D4/metabolism , Reward , Up-Regulation/genetics , Young AdultABSTRACT
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.