Publications by authors named "Isabelle Austin-Zimmerman"
Background: Cannabis use severely affects the outcome of people with psychotic disorders, yet there is a lack of treatments. To address this, in 2019 the National Health Service (NHS) Cannabis Clinic for Psychosis (CCP) was developed to support adults suffering from psychosis to reduce and/or stop their cannabis use.
Aims: Examine outcome data from the first 46 individuals to complete the CCP's intervention.
Background: The association between cannabis and psychosis is established, but the role of underlying genetics is unclear. We used data from the EU-GEI case-control study and UK Biobank to examine the independent and combined effect of heavy cannabis use and schizophrenia polygenic risk score (PRS) on risk for psychosis.
Methods: Genome-wide association study summary statistics from the Psychiatric Genomics Consortium and the Genomic Psychiatry Cohort were used to calculate schizophrenia and cannabis use disorder (CUD) PRS for 1098 participants from the EU-GEI study and 143600 from the UK Biobank.
Article Synopsis
- The study investigates how current cannabis use and high-potency cannabis affect DNA methylation patterns in individuals experiencing first-episode psychosis (FEP), comparing them to non-users.
- Researchers analyzed blood samples from 682 participants, identifying a significant CpG site associated with cannabis use that could influence mental health through epigenetic changes.
- Findings suggest cannabis use affects genes related to immune and mitochondrial functions, with implications for understanding how cannabis may impact mental health, especially in those with psychosis.
Article Synopsis
- This meta-analysis investigates the impact of adolescent cannabinoid exposure on schizophrenia-like behaviors in rodents, highlighting a significant connection supported by various studies.
- It analyzed data from 359 experiments, showing that cannabinoid exposure led to notable impairments in working memory and social behaviors, while also observing variations in experimental methods used.
- The findings suggest that both natural and synthetic cannabinoids can produce schizophrenia-like effects, with additional insights indicating that CBD might influence fear memory recall, although more research is needed.
Individuals with schizophrenia frequently experience co-occurring substance use, including tobacco smoking and heavy cannabis use, and substance use disorders. There is interest in understanding the extent to which these relationships are causal, and to what extent shared genetic factors play a role. We explored the relationships between schizophrenia (Scz; European ancestry N = 161,405; African ancestry N = 15,846), cannabis use disorder (CanUD; European ancestry N = 886,025; African ancestry N = 120,208), and ever-regular tobacco smoking (Smk; European ancestry N = 805,431; African ancestry N = 24,278) using the largest available genome-wide studies of these phenotypes in individuals of African and European ancestries.
View Article and Find Full Text PDFIndividuals with schizophrenia frequently experience co-occurring substance use, including tobacco smoking and heavy cannabis use, and substance use disorders. There is interest in understanding the extent to which these relationships are causal, and to what extent shared genetic factors play a role. We explored the relationships between schizophrenia (Scz), cannabis use disorder (CanUD), and ever-regular tobacco smoking (Smk) using the largest available genome-wide studies of these phenotypes in individuals of African and European ancestries.
View Article and Find Full Text PDFBackground: Childhood adversity and cannabis use are considered independent risk factors for psychosis, but whether different patterns of cannabis use may be acting as mediator between adversity and psychotic disorders has not yet been explored. The aim of this study is to examine whether cannabis use mediates the relationship between childhood adversity and psychosis.
Methods: Data were utilised on 881 first-episode psychosis patients and 1231 controls from the European network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI) study.
Article Synopsis
- Research shows sleep duration is linked to negative health effects and shorter life expectancy, with studies involving nearly 500,000 adults from different ethnic backgrounds.* -
- The study identifies 84 genetic loci associated with short sleep (≤ 5 hours) and 1 with long sleep (≥ 10 hours), indicating genetic factors influence sleep duration.* -
- Findings suggest a positive genetic correlation between short and long sleep, as well as causal relationships with depression, where short sleep may lead to depression and long sleep may also be related to it.*
Article Synopsis
- The study investigates how endophenotypes, which are traits linked to psychosis, connect to genetic factors by examining specific gene sets.
- It analyzed data from 4,506 participants to compute polygenic risk scores related to schizophrenia and bipolar disorder, ultimately measuring their association with seven different endophenotypes.
- Results indicated a significant link between reduced P300 amplitude and higher schizophrenia risk linked to forebrain-related genes, suggesting genetic variants influence early brain development and may heighten psychosis risk in the future.
Background: While cannabis use is a well-established risk factor for psychosis, little is known about any association between reasons for first using cannabis (RFUC) and later patterns of use and risk of psychosis.
Methods: We used data from 11 sites of the multicentre European Gene-Environment Interaction (EU-GEI) case-control study. 558 first-episode psychosis patients (FEPp) and 567 population controls who had used cannabis and reported their RFUC.
Background: Dyslipidaemia is an important cardiovascular risk factor for people with severe mental illness, contributing to premature mortality. The link between antipsychotics and dyslipidaemia is well established, while evidence on antidepressants is mixed.
Aims: To investigate if antidepressant/antipsychotic use was associated with lipid parameters in UK Biobank participants and if and genetic variation plays a role.
Article Synopsis
- Antipsychotic medications can lead to weight gain, which may reduce life expectancy in individuals with psychotic disorders, potentially influenced by genetic variations in the CYP2D6 enzyme responsible for drug metabolism.
- A systematic review analyzed various studies on the weight and BMI of patients on antipsychotics based on their CYP2D6 metabolic groups, finding that cohort studies indicated higher weight in poor metabolizers, but cross-sectional studies did not support this.
- The meta-analysis of 17 studies, encompassing data from over 2,000 patients, did not reveal significant differences in weight or BMI among different metabolic groups, suggesting that genetic factors may not strongly influence weight gain in antipsychotic treatment.
Verbal memory impairment is one of the most prominent cognitive deficits in psychosis. However, few studies have investigated the genetic basis of verbal memory in a neurodevelopmental context, and most genome-wide association studies (GWASs) have been conducted in European-ancestry populations. We conducted a GWAS on verbal memory in a maximum of 11,017 participants aged 8.
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- CYP2D6 and CYP2C19 enzymes play a crucial role in how the body processes antidepressants and antipsychotics, and genetic differences in these enzymes can increase the risk of adverse drug reactions and diabetes.
- In a study involving 31,579 individuals on antidepressants and 2,699 on antipsychotics, it was found that poor metabolizers of CYP2D6 had significantly higher HbA1c levels (a diabetes measure) compared to normal metabolizers when taking specific medications like paroxetine and venlafaxine.
- Results suggest the relationship between genetic metabolism status and diabetes varies, highlighting the need for further research to enhance pharmacogenetic testing for those on these medications.
Mismatch negativity (MMN) is a differential electrophysiological response measuring cortical adaptability to unpredictable stimuli. MMN is consistently attenuated in patients with psychosis. However, the genetics of MMN are uncharted, limiting the validation of MMN as a psychosis endophenotype.
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- * A systematic review involved ten studies with nearly 19,000 participants, concluding that the burden of CNVs does not correlate with general cognitive performance.
- * However, specific schizophrenia-associated CNVs were linked to poorer verbal recall and perceptual reasoning abilities in individuals with psychotic disorders and their relatives, suggesting they may serve as biomarkers for cognitive impairment and increased disease risk.
Hyperprolactinemia is a known adverse drug reaction to antipsychotic treatment. Antipsychotic blood levels are influenced by cytochrome P450 enzymes, primarily CYP2D6. Variation in CYP450 genes may affect the risk of antipsychotic-induced hyperprolactinemia.
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