scholarly journals Bridging the Gap? Altered Thalamocortical Connectivity in Psychotic and Psychedelic States

2021 ◽  
Vol 12 ◽  
Author(s):  
Mihai Avram ◽  
Helena Rogg ◽  
Alexandra Korda ◽  
Christina Andreou ◽  
Felix Müller ◽  
...  

Psychiatry has a well-established tradition of comparing drug-induced experiences to psychotic symptoms, based on shared phenomena such as altered perceptions. The present review focuses on experiences induced by classic psychedelics, which are substances capable of eliciting powerful psychoactive effects, characterized by distortions/alterations of several neurocognitive processes (e.g., hallucinations). Herein we refer to such experiences as psychedelic states. Psychosis is a clinical syndrome defined by impaired reality testing, also characterized by impaired neurocognitive processes (e.g., hallucinations and delusions). In this review we refer to acute phases of psychotic disorders as psychotic states. Neuropharmacological investigations have begun to characterize the neurobiological mechanisms underpinning the shared and distinct neurophysiological changes observed in psychedelic and psychotic states. Mounting evidence indicates changes in thalamic filtering, along with disturbances in cortico-striato-pallido-thalamo-cortical (CSPTC)-circuitry, in both altered states. Notably, alterations in thalamocortical functional connectivity were reported by functional magnetic resonance imaging (fMRI) studies. Thalamocortical dysconnectivity and its clinical relevance are well-characterized in psychotic states, particularly in schizophrenia research. Specifically, studies report hyperconnectivity between the thalamus and sensorimotor cortices and hypoconnectivity between the thalamus and prefrontal cortices, associated with patients' psychotic symptoms and cognitive disturbances, respectively. Intriguingly, studies also report hyperconnectivity between the thalamus and sensorimotor cortices in psychedelic states, correlating with altered visual and auditory perceptions. Taken together, the two altered states appear to share clinically and functionally relevant dysconnectivity patterns. In this review we discuss recent findings of thalamocortical dysconnectivity, its putative extension to CSPTC circuitry, along with its clinical implications and future directions.

2020 ◽  
Vol 2020 ◽  
pp. 1-5 ◽  
Author(s):  
Juan Pablo Lucchelli ◽  
Stamatia Kourakou ◽  
Laia Pérez de Lucia Bové ◽  
Daniel Diaz Rodriguez

Catatonia is a complex identifiable clinical syndrome characterized primarily by psychomotor symptoms. In recent decades, some authors have considered that catatonia can be presented as a catatonic syndrome in several pathologies such as bipolar disorder, schizophrenia and other psychotic disorders and not only in schizophrenia. Prior to DSM 5, there were two conceptions of catatonia: one in which clinical characterization seemed to play a determining role (a categorical view) and another in which a dimensional perspective advocated the existence of catatonia as a clinical entity in its own right, detached from the underlying pathology. Although there are no definitive consensus guidelines for the treatment of catatonia, some studies show that in the schizophrenic form of catatonia, benzodiazepines are partially effective, as well as treatment with ECT. We present the case of a 24-year-old man with severe catatonia and psychotic symptoms, resistant to lorazepam treatment, who achieved complete remission with clozapine treatment according to our diagnostic hypothesis of schizophrenia.


1988 ◽  
Vol 18 (1) ◽  
pp. 33-47
Author(s):  
William A. Emboden

Historical and contemporary patterns of substance use and abuse are recognized, and the error in believing psychoactive natural substances to be reasonably safe is pointed out. The plethora of literature on drug-induced ecstasies among diverse peoples produces over-confidence in the safety of inducing altered states by means of natural chemicals. Given the current level of experimentation, the lack of a context for use, and the lack of knowledge of the toxicity of many plant sources presents a very real problem. Documented evidence of recent changes in patterns of experimentation with diverse drugs, many from natural sources, suggests that the naive user may experience an unwarranted level of confidence. Diverse genera and species of plants that produce psychoactive effects are presented. Many of these are now in use and others will undoubtedly be the subject of uncontrolled experimentation in the future. Educators, researchers, legislators, physicians, and therapists should be aware of chemicals from natural sources, and the categories of experience that they provoke.


2021 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Piyush Varma ◽  
Lakshanaa Narayan ◽  
Jane Alty ◽  
Virginia Painter ◽  
Chandrasekhara Padmakumar

Introduction: Parkinson’s disease is a heterogeneous clinical syndrome. Parkinson’s disease in older persons presents with a diverse array of clinical manifestations leading to unique care needs. This raises the need for the healthcare community to proactively address the care needs of older persons with Parkinson’s disease. Though it is tempting to categorise different phenotypes of Parkinson’s disease, a strong evidence based for the same is lacking. There is considerable literature describing the varying clinical manifestations in old age. This article aims to review the literature looking for strategies in personalising the management of an older person with Parkinson’s disease.


Author(s):  
Brandon Gunasekera ◽  
Kelly Diederen ◽  
Sagnik Bhattacharyya

Abstract Background Evidence suggests that an overlap exists between the neurobiology of psychotic disorders and the effects of cannabinoids on neurocognitive and neurochemical substrates involved in reward processing. Aims We investigate whether the psychotomimetic effects of delta-9-tetrahydrocannabinol (THC) and the antipsychotic potential of cannabidiol (CBD) are underpinned by their effects on the reward system and dopamine. Methods This narrative review focuses on the overlap between altered dopamine signalling and reward processing induced by cannabinoids, pre-clinically and in humans. A systematic search was conducted of acute cannabinoid drug-challenge studies using neuroimaging in healthy subjects and those with psychosis Results There is evidence of increased striatal presynaptic dopamine synthesis and release in psychosis, as well as abnormal engagement of the striatum during reward processing. Although, acute THC challenges have elicited a modest effect on striatal dopamine, cannabis users generally indicate impaired presynaptic dopaminergic function. Functional MRI studies have identified that a single dose of THC may modulate regions involved in reward and salience processing such as the striatum, midbrain, insular, and anterior cingulate, with some effects correlating with the severity of THC-induced psychotic symptoms. CBD may modulate brain regions involved in reward/salience processing in an opposite direction to that of THC. Conclusions There is evidence to suggest modulation of reward processing and its neural substrates by THC and CBD. Whether such effects underlie the psychotomimetic/antipsychotic effects of these cannabinoids remains unclear. Future research should address these unanswered questions to understand the relationship between endocannabinoid dysfunction, reward processing abnormalities, and psychosis.


2021 ◽  
pp. 025371762199953
Author(s):  
Bhavneesh Saini ◽  
Pir Dutt Bansal ◽  
Mamta Bahetra ◽  
Arvind Sharma ◽  
Priyanka Bansal ◽  
...  

Background: Normal personality development, gone awry due to genetic or environmental factors, results in personality disorders (PD). These often coexist with other psychiatric disorders, affecting their outcome adversely. Considering the heterogeneity of data, more research is warranted. Methods: This was a cross-sectional study on personality traits in psychiatric patients of a tertiary hospital, over 1 year. Five hundred and twenty-five subjects, aged 18–45 years, with substance, psychotic, mood, or neurotic disorders were selected by convenience sampling. They were evaluated for illness-related variables using psychiatric pro forma; diagnostic confirmation and severity assessment were done using ICD-10 criteria and suitable scales. Personality assessment was done using the International Personality Disorder Examination after achieving remission. Results: Prevalence of PD traits and PDs was 56.3% and 4.2%, respectively. While mood disorders were the diagnostic group with the highest prevalence of PD traits, it was neurotic disorders for PDs. Patients with PD traits had a past psychiatric history and upper middle socioeconomic status (SES); patients with PDs were urban and unmarried. Both had a lower age of onset of psychiatric illness. Psychotic patients with PD traits had higher and lower PANSS positive and negative scores, respectively. The severity of personality pathology was highest for mixed cluster and among neurotic patients. Clusterwise prevalence was cluster C > B > mixed > A (47.1%, 25.2%, 16.7%, and 11.4%). Among subtypes, anankastic (18.1%) and mixed (16.7%) had the highest prevalence. Those in the cluster A group were the least educated and with lower SES than others. Conclusions: PD traits were present among 56.3% of the patients, and they had many significant sociodemographic and illness-related differences from those without PD traits. Cluster C had the highest prevalence. Among patients with psychotic disorders, those with PD traits had higher severity of psychotic symptoms.


PLoS ONE ◽  
2015 ◽  
Vol 10 (6) ◽  
pp. e0125103 ◽  
Author(s):  
Marije Swets ◽  
Frank Van Dael ◽  
Sabine Roza ◽  
Robert Schoevers ◽  
Inez Myin-Germeys ◽  
...  

CNS Spectrums ◽  
1999 ◽  
Vol 4 (9) ◽  
pp. 64-66,82 ◽  
Author(s):  
Bonnie J. Ramsey

AbstractAlthough psychotic symptoms are a recognized manifestation of epilepsy, these are more often associated with seizures of the temporal lobe type. While 10% of children with temporal lobe epilepsy develop a psychotic disorder by adulthood, the literature does not report any cases of psychotic disorders associated with frontal lobe seizures in children. This article presents a unique case of a girl whose frontal lobe seizures were associated with delusional psychotic symptoms. Once her seizure disorder was identified through electroencephalography (EEG) and appropriate anticonvulsant therapy was initiated, her associated psychotic symptoms resolved.


2014 ◽  
Vol 44 (11) ◽  
pp. 2419-2430 ◽  
Author(s):  
F. J. Oher ◽  
A. Demjaha ◽  
D. Jackson ◽  
C. Morgan ◽  
P. Dazzan ◽  
...  

BackgroundThe extent to which different symptom dimensions vary according to epidemiological factors associated with categorical definitions of first-episode psychosis (FEP) is unknown. We hypothesized that positive psychotic symptoms, including paranoid delusions and depressive symptoms, would be more prominent in more urban environments.MethodWe collected clinical and epidemiological data on 469 people with FEP (ICD-10 F10–F33) in two centres of the Aetiology and Ethnicity in Schizophrenia and Other Psychoses (AESOP) study: Southeast London and Nottinghamshire. We used multilevel regression models to examine neighbourhood-level and between-centre differences in five symptom dimensions (reality distortion, negative symptoms, manic symptoms, depressive symptoms and disorganization) underpinning Schedules for Clinical Assessment in Neuropsychiatry (SCAN) Item Group Checklist (IGC) symptoms. Delusions of persecution and reference, along with other individual IGC symptoms, were inspected for area-level variation.ResultsReality distortion [estimated effect size (EES) 0.15, 95% confidence interval (CI) 0.06–0.24] and depressive symptoms (EES 0.21, 95% CI 0.07–0.34) were elevated in people with FEP living in more urban Southeast London but disorganized symptomatology was lower (EES –0.06, 95% CI –0.10 to –0.02), after controlling for confounders. Delusions of persecution were not associated with increased neighbourhood population density [adjusted odds ratio (aOR) 1.01, 95% CI 0.83–1.23], although an effect was observed for delusions of reference (aOR 1.41, 95% CI 1.12–1.77). Hallucinatory symptoms showed consistent elevation in more densely populated neighbourhoods (aOR 1.32, 95% CI 1.09–1.61).ConclusionsIn people experiencing FEP, elevated levels of reality distortion and depressive symptoms were observed in more urban, densely populated neighbourhoods. No clear association was observed for paranoid delusions; hallucinations were consistently associated with increased population density. These results suggest that urban environments may affect the syndromal presentation of psychotic disorders.


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