Effect of Pharmacological Interventions on the Fronto-Cingulo-Parietal Cognitive Control Network in Psychiatric Disorders: A Transdiagnostic Systematic Review of fMRI Studies

Executive function deficits such as working memory, decision-making, and attention problems are a common feature of several psychiatric disorders for which no satisfactory treatment exists. Here, we transdiagnostically investigate the effects of pharmacological interventions (other than methylphenidate) on the fronto-cingulo-parietal cognitive control network, in order to identify functional brain markers for future pro-cognitive pharmacological interventions. 29 manuscripts investigated the effect of pharmacological treatment on executive function-related brain correlates in psychotic disorders (n=11), depression (n=4), bipolar disorder (n=4), ADHD (n=4), OCD (n=2), smoking dependence (n=2), alcohol dependence (n=1) and pathological gambling (n=1). In terms of impact on the fronto-cingulo-parietal networks, the preliminary evidence for catechol-o-methyl-transferase inhibitors, nicotinic receptor agonists and atomoxetine suggested was relatively consistent, the data for atypical antipsychotics and anticonvulsants moderate, and interpretation of the data for antidepressants was hampered by the employed study designs. Increased activity in task-relevant areas and decreased activity in task-irrelevant areas were the most common transdiagnostic effects of pharmacological treatment. These markers showed good positive and moderate negative predictive value. It is concluded that fronto-cingulo-parietal activity changes can serve as a marker for future pro-cognitive interventions. Future recommendations include the use of randomized double-blind designs and selective cholinergic and glutamatergic compounds

The muscarinic M1 receptor modulates associative learning and memory in psychotic disorders.

BACKGROUND: Psychotic disorders are characterized by prominent deficits in associative learning and memory for which there are currently no effective treatments. Functional magnetic resonance imaging (fMRI) studies in psychotic disorders have identified deficits in fronto-temporal activation during associative learning and memory. The underlying pathology of these findings remains unclear. Postmortem data have suggested these deficits may be related to loss of muscarinic M1 receptor mediated signaling. This is supported by an in-vivo study showing improvements in these symptoms after treatment with the experimental M1/4 receptor agonist xanomeline. The current study tests whether reported deficits in fronto-temporal activation could be mediated by loss of M1 receptor signaling in psychotic disorders. METHODS: Twenty-six medication-free subjects diagnosed with a psychotic disorder and 29 age-, gender-, and IQ-matched healthy controls underwent two functional magnetic resonance imaging (fMRI) sessions, one under placebo and one under selective M1 antagonist biperiden, while performing the paired associated learning task. M1 binding potentials (BPND) were measured in the dorsolateral prefrontal cortex (DLPFC) and hippocampus using 123I-IDEX single photon emission computed tomography. RESULTS: In the subjects with psychotic disorders DLPFC hypoactivation was only found in the memory phase of the task. In both learning and memory phases of the task, M1 antagonism by biperiden elicited significantly greater hyperactivation of the parahippocampal gyrus and superior temporal gyrus in subjects with a psychotic disorders compared to controls. Greater hyperactivation of these areas after biperiden was associated with greater hippocampal M1 receptor binding during learning, with no association found with M1 receptor binding in the DLPFC. M1 receptor binding in the DLPFC was related to greater functional sensitivity to biperiden of the cingulate gyrus during the memory phase. CONCLUSION: The current study is the first to show differences in M1 receptor mediated functional sensitivity between subjects with a psychotic disorder and controls during a paired associate learning and memory task. Results point to subjects with psychotic disorders having a loss of M1 receptor reserve in temporal-limbic areas

A Network of Psychopathological, Cognitive, and Motor Symptoms in Schizophrenia Spectrum Disorders

Schizophrenia spectrum disorders (SSDs) are complex syndromes involving psychopathological, cognitive, and also motor symptoms as core features. A better understanding of how these symptoms mutually impact each other could translate into diagnostic, prognostic, and, eventually, treatment advancements. The present study aimed to: (1) estimate a network model of psychopathological, cognitive, and motor symptoms in SSD; (2) detect communities and explore the connectivity and relative importance of variables within the network; and (3) explore differences in subsample networks according to remission status. A sample of 1007 patients from a multisite cohort study was included in the analysis. We estimated a network of 43 nodes, including all the items from the Positive and Negative Syndrome Scale, a cognitive assessment battery and clinical ratings of extrapyramidal symptoms. Methodologies specific to network analysis were employed to address the study’s aims. The estimated network for the total sample was densely interconnected and organized into 7 communities. Nodes related to insight, abstraction capacity, attention, and suspiciousness were the main bridges between network communities. The estimated network for the subgroup of patients in remission showed a sparser density and a different structure compared to the network of nonremitted patients. In conclusion, the present study conveys a detailed characterization of the interrelations between a set of core clinical elements of SSD. These results provide potential novel clues for clinical assessment and intervention

Medication strategies in first episode psychosis patients:A survey among psychiatrists

Aim There is an ongoing debate regarding the optimal timing of discontinuation of antipsychotic drugs for patients with first episode psychosis. Although most guidelines recommend maintenance therapy for at least 1 or 2 years after reaching remission, study results indicate that early discontinuation may be beneficial for at least a subsample of patients. To date, little is known about which medication strategies are applied in patients recovering from a first psychotic episode. In this study, we examined the beliefs and practices of clinicians on medication discontinuation. Methods We performed a survey among 50 experienced Dutch psychiatrists to assess how often specific treatment strategies have been applied in the past 12 months, as well as their knowledge and expectations with respect to medication discontinuation. Results Psychiatrists estimated that, after remission, they continued medication at the same dose for at least 12 months in 51.2% of cases, continued in a reduced dose in 33.8% of cases and discontinued medication in 9.1% of cases after 4.4 months of remission on average. Although the medication is discontinued in only a relatively small proportion of patients, almost half of all clinicians (45.9%) used this strategy at least once in the past 12 months. Conclusions There is substantial practice variation in antipsychotic medication strategies after remission from a first psychotic episode. Future research on long-term effects of early medication discontinuation can guide clinicians in making evidence-based decisions when treating first-episode patients

Lower striatal dopamine D2/3 receptor availability in obese compared with non-obese subjects

Background: Obesity is a result of a relative excess in energy intake over energy expenditure. These processes are controlled by genetic, environmental, psychological and biological factors. One of the factors involved in the regulation of food intake and satiety is dopaminergic signalling. A small number of studies have reported that striatal dopamine D-2/D-3 receptor [D2/3R] availability is lower in morbidly obese subjects. Methods: To confirm the role of D2/3R in obesity, we measured striatal D2/3R availability, using [I-123]IBZM SPECT, in 15 obese women and 15 non-obese controls. Results: Striatal D2/3R availability was 23% (p = 0.028) lower in obese compared with non-obese women. Conclusion: This study is an independent replication of the finding that severely obese subjects have lower striatal D2/3R availability. Our findings invigorate the evidence for lower striatal D2/3R availability in obesity and confirm the role of the striatal dopaminergic reward system in obesit

Phenome-wide and genome-wide analyses of quality of life in schizophrenia

This article has been published in a revised form in BJPsych Open [http://doi.org/10.1192/bjo.2020.140]. This version is free to view and download for private research and study only. Not for re-distribution or re-use. © copyright holder.Background Schizophrenia negatively affects quality of life (QoL). A handful of variables from small studies have been reported to influence QoL in patients with schizophrenia, but a study comprehensively dissecting the genetic and non-genetic contributing factors to QoL in these patients is currently lacking. Aims We adopted a hypothesis-generating approach to assess the phenotypic and genotypic determinants of QoL in schizophrenia. Method The study population comprised 1119 patients with a psychotic disorder, 1979 relatives and 586 healthy controls. Using linear regression, we tested >100 independent demographic, cognitive and clinical phenotypes for their association with QoL in patients. We then performed genome-wide association analyses of QoL and examined the association between polygenic risk scores for schizophrenia, major depressive disorder and subjective well-being and QoL. Results We found nine phenotypes to be significantly and independently associated with QoL in patients, the most significant ones being negative (β = −1.17; s.e. 0.05; P = 1 × 10–83; r2 = 38%), depressive (β = −1.07; s.e. 0.05; P = 2 × 10–79; r2 = 36%) and emotional distress (β = −0.09; s.e. 0.01; P = 4 × 10–59, r2 = 25%) symptoms. Schizophrenia and subjective well-being polygenic risk scores, using various P-value thresholds, were significantly and consistently associated with QoL (lowest association P-value = 6.8 × 10–6). Several sensitivity analyses confirmed the results. Conclusions Various clinical phenotypes of schizophrenia, as well as schizophrenia and subjective well-being polygenic risk scores, are associated with QoL in patients with schizophrenia and their relatives. These may be targeted by clinicians to more easily identify vulnerable patients with schizophrenia for further social and clinical interventions to improve their QoL.Dutch Health Research Council; Lundbeck; AstraZeneca; Eli Lilly; Janssen Cilag;Amsterdam: Academic Psychiatric Centre of the Academic Medical Center and the mental health institutions at Geestelijke Gezondheidszorg (GGZ) Ingeest; Arkin; Dijk en Duin; GGZ Rivierduinen; Erasmus Medical Centre and GGZ Noord Holland Noord; Groningen: University Medical Center Groningen and the mental health institutions at Lentis; GGZ Friesland; GGZ Drenthe; Dimence; Mediant; GGNet Warnsveld; Yulius Dordrecht and Parnassia Psycho-Medical Center The Hague; Maastricht: Maastricht University Medical Centre and the mental health institutions at GGZ Eindhoven en De Kempen; GGZ Breburg; GGZ Oost-Brabant; Vincent van Gogh voor Geestelijke Gezondheid; Mondriaan; Virenze riagg; Zuyderland GGZ; MET ggz; Universitair Centrum Sint-Jozef Kortenberg; Collaborative Antwerp Psychiatric Research Institute University of Antwerp; Psychiatrisch Centrum Ziekeren Sint-Truiden; Psychiatrisch Ziekenhuis Sancta Maria Sint-Truiden; GGZ Overpelt and Openbaar Psychiatrisch Zorgcentrum Rekem; Utrecht: University Medical Center Utrecht and the mental health institutions Altrecht; GGZ Centraal and Delt

Prescription of antipsychotic medication to patients at ultra high risk of developing psychosis

Little is known about medication prescription in a naturalistic setting to patients at ultra high risk (UHR) of developing psychosis. Antipsychotic medication prescription to UHR patients is not recommended in clinical practice guidelines based on the current evidence. The aim of this study is to investigate medication prescription to UHR patients in the Netherlands. The frequency of antipsychotic medication prescription to UHR patients (n=72) was compared with the frequency of antipsychotic medication prescription to patients who were diagnosed with a Diagnostic and Statistical Manual of Mental Disorders, fourth edition psychotic disorder at first diagnostic evaluation (n=90). Within the UHR group, frequency of antipsychotic medication prescription at baseline was compared between UHR patients who did make the transition to psychosis (n=18) and UHR patients who did not (n=54). No significant differences were found in antipsychotic medication prescription to UHR patients and to patients who turned out to have a florid psychosis: 51% in the psychotic group and 58% in the UHR group used no medication. Thirty-four percent in the psychotic group and 21% in the UHR group used antipsychotic medication. There was also no difference in medication prescription between UHR patients who did and did not make the transition to psychosis. More research should be aimed at developing and implementing clinical practice guidelines for the treatment of UHR patients

Variability and magnitude of brain glutamate levels in schizophrenia: a meta and mega-analysis

Glutamatergic dysfunction is implicated in schizophrenia pathoaetiology, but this may vary in extent between patients. It is unclear whether inter-individual variability in glutamate is greater in schizophrenia than the general population. We conducted meta-analyses to assess (1) variability of glutamate measures in patients relative to controls (log coefficient of variation ratio: CVR); (2) standardised mean differences (SMD) using Hedges g; (3) modal distribution of individual-level glutamate data (Hartigan’s unimodality dip test). MEDLINE and EMBASE databases were searched from inception to September 2022 for proton magnetic resonance spectroscopy (1H-MRS) studies reporting glutamate, glutamine or Glx in schizophrenia. 123 studies reporting on 8256 patients and 7532 controls were included. Compared with controls, patients demonstrated greater variability in glutamatergic metabolites in the medial frontal cortex (MFC, glutamate: CVR = 0.15, p < 0.001; glutamine: CVR = 0.15, p = 0.003; Glx: CVR = 0.11, p = 0.002), dorsolateral prefrontal cortex (glutamine: CVR = 0.14, p = 0.05; Glx: CVR = 0.25, p < 0.001) and thalamus (glutamate: CVR = 0.16, p = 0.008; Glx: CVR = 0.19, p = 0.008). Studies in younger, more symptomatic patients were associated with greater variability in the basal ganglia (BG glutamate with age: z = −0.03, p = 0.003, symptoms: z = 0.007, p = 0.02) and temporal lobe (glutamate with age: z = −0.03, p = 0.02), while studies with older, more symptomatic patients associated with greater variability in MFC (glutamate with age: z = 0.01, p = 0.02, glutamine with symptoms: z = 0.01, p = 0.02). For individual patient data, most studies showed a unimodal distribution of glutamatergic metabolites. Meta-analysis of mean differences found lower MFC glutamate (g = −0.15, p = 0.03), higher thalamic glutamine (g = 0.53, p < 0.001) and higher BG Glx in patients relative to controls (g = 0.28, p < 0.001). Proportion of males was negatively associated with MFC glutamate (z = −0.02, p < 0.001) and frontal white matter Glx (z = −0.03, p = 0.02) in patients relative to controls. Patient PANSS total score was positively associated with glutamate SMD in BG (z = 0.01, p = 0.01) and temporal lobe (z = 0.05, p = 0.008). Further research into the mechanisms underlying greater glutamatergic metabolite variability in schizophrenia and their clinical consequences may inform the identification of patient subgroups for future treatment strategies