Browsing by Author "Ballard, Clive"

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    Agitation and impulsivity in mid and late life as possible risk markers for incident dementia
    (Wiley, 2020-09-06) Bateman, Daniel R.; Gill, Sascha; Hu, Sophie; Foster, Erin D.; Ruthirakuhan, Myuri T.; Sellek, Allis F.; Mortby, Moyra E.; Matušková, Veronika; Ng, Kok Pin; Tarawneh, Rawan M.; Freund‐Levi, Yvonne; Kumar, Sanjeev; Gauthier, Serge; Rosenberg, Paul B.; Oliveira, Fabricio Ferreira de; Devanand, D. P.; Ballard, Clive; Ismail, Zahinoor; Psychiatry, School of Medicine
    To identify knowledge gaps regarding new‐onset agitation and impulsivity prior to onset of cognitive impairment or dementia the International Society to Advance Alzheimer's Research and Treatment Neuropsychiatric Syndromes (NPS) Professional Interest Area conducted a scoping review. Extending a series of reviews exploring the pre‐dementia risk syndrome Mild Behavioral Impairment (MBI), we focused on late‐onset agitation and impulsivity (the MBI impulse dyscontrol domain) and risk of incident cognitive decline and dementia. This scoping review of agitation and impulsivity pre‐dementia syndromes summarizes the current biomedical literature in terms of epidemiology, diagnosis and measurement, neurobiology, neuroimaging, biomarkers, course and prognosis, treatment, and ongoing clinical trials. Validations for pre‐dementia scales such as the MBI Checklist, and incorporation into longitudinal and intervention trials, are needed to better understand impulse dyscontrol as a risk factor for mild cognitive impairment and dementia.
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    Genetic associations with psychosis and affective disturbance in Alzheimer's disease
    (Wiley, 2024-05-23) Antonsdottir, Inga Margret; Creese, Byron; Klei, Lambertus; DeMichele-Sweet, Mary Ann A.; Weamer, Elise A.; Garcia-Gonzalez, Pablo; Marquie, Marta; Boada, Mercè; Alarcón-Martín, Emilio; Valero, Sergi; NIA-LOAD Family Based Study Consortium; Alzheimer's Disease Genetics Consortium (ADGC); AddNeuroMed Consortium; Liu, Yushi; Hooli, Basavaraj; Aarsland, Dag; Selbaek, Geir; Bergh, Sverre; Rongve, Arvid; Saltvedt, Ingvild; Skjellegrind, Håvard K.; Engdahl, Bo; Andreassen, Ole A.; Borroni, Barbara; Mecocci, Patrizia; Wedatilake, Yehani; Mayeux, Richard; Foroud, Tatiana; Ruiz, Agustín; Lopez, Oscar L.; Kamboh, M. Ilyas; Ballard, Clive; Devlin, Bernie; Lyketsos, Constantine; Sweet, Robert A.; Medical and Molecular Genetics, School of Medicine
    Introduction: Individuals with Alzheimer's disease (AD) commonly experience neuropsychiatric symptoms of psychosis (AD+P) and/or affective disturbance (depression, anxiety, and/or irritability, AD+A). This study's goal was to identify the genetic architecture of AD+P and AD+A, as well as their genetically correlated phenotypes. Methods: Genome-wide association meta-analysis of 9988 AD participants from six source studies with participants characterized for AD+P AD+A, and a joint phenotype (AD+A+P). Results: AD+P and AD+A were genetically correlated. However, AD+P and AD+A diverged in their genetic correlations with psychiatric phenotypes in individuals without AD. AD+P was negatively genetically correlated with bipolar disorder and positively with depressive symptoms. AD+A was positively correlated with anxiety disorder and more strongly correlated than AD+P with depressive symptoms. AD+P and AD+A+P had significant estimated heritability, whereas AD+A did not. Examination of the loci most strongly associated with the three phenotypes revealed overlapping and unique associations. Discussion: AD+P, AD+A, and AD+A+P have both shared and divergent genetic associations pointing to the importance of incorporating genetic insights into future treatment development. Highlights: It has long been known that psychotic and affective symptoms are often comorbid in individuals diagnosed with Alzheimer's disease. Here we examined for the first time the genetic architecture underlying this clinical observation, determining that psychotic and affective phenotypes in Alzheimer's disease are genetically correlated. Nevertheless, psychotic and affective phenotypes in Alzheimer's disease diverged in their genetic correlations with psychiatric phenotypes assessed in individuals without Alzheimer's disease. Psychosis in Alzheimer's disease was negatively genetically correlated with bipolar disorder and positively with depressive symptoms, whereas the affective phenotypes in Alzheimer's disease were positively correlated with anxiety disorder and more strongly correlated than psychosis with depressive symptoms. Psychosis in Alzheimer's disease, and the joint psychotic and affective phenotype, had significant estimated heritability, whereas the affective in AD did not. Examination of the loci most strongly associated with the psychotic, affective, or joint phenotypes revealed overlapping and unique associations.
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    Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease
    (Springer Nature, 2021) DeMichele-Sweet, Mary Ann A.; Klei, Lambertus; Creese, Byron; Harwood, Janet C.; Weamer, Elise A.; McClain, Lora; Sims, Rebecca; Hernandez, Isabel; Moreno-Grau, Sonia; Tárraga, Lluís; Boada, Mercè; Alarcón-Martín, Emilio; Valero, Sergi; NIA-LOAD Family Based Study Consortium; Alzheimer’s Disease Genetics Consortium (ADGC); Liu, Yushi; Hooli, Basavaraj; Aarsland, Dag; Selbaek, Geir; Bergh, Sverre; Rongve, Arvid; Saltvedt, Ingvild; Skjellegrind, Håvard K.; Engdahl, Bo; Stordal, Eystein; Andreassen, Ole A.; Djurovic, Srdjan; Athanasiu, Lavinia; Seripa, Davide; Borroni, Barbara; Albani, Diego; Forloni, Gianluigi; Mecocci, Patrizia; Serretti, Alessandro; De Ronchi, Diana; Politis, Antonis; Williams, Julie; Mayeux, Richard; Foroud, Tatiana; Ruiz, Agustín; Ballard, Clive; Holmans, Peter; Lopez, Oscar L.; Kamboh, M. Ilyas; Devlin, Bernie; Sweet, Robert A.; Medical and Molecular Genetics, School of Medicine
    Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD - P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10-8) and one spanning the 3'-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56-0.76), p = 3.24 × 10-8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.
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    (-)-Phenserine and Inhibiting Pre-Programmed Cell Death: In Pursuit of a Novel Intervention for Alzheimer's Disease
    (Bentham Science Publishers, 2018) Becker, Robert E.; Greig, Nigel H.; Schneider, Lon S.; Ballard, Clive; Aarsland, Dag; Lahiri, Debomoy K.; Flanagan, Douglas; Govindarajan, Ramprakash; Sano, Mary; Kapogiannis, Dimitrios; Ferrucci, Luigi; Psychiatry, School of Medicine
    BACKGROUND: Concussion (mild) and other moderate traumatic brain injury (TBI) and Alzheimer's disease (AD) share overlapping neuropathologies, including neuronal pre-programmed cell death (PPCD), and clinical impairments and disabilities. Multiple clinical trials targeting mechanisms based on the Amyloid Hypothesis of AD have so far failed, indicating that it is prudent for new drug developments to also pursue mechanisms independent of the Amyloid Hypothesis. To address these issues, we have proposed the use of an animal model of concussion/TBI as a supplement to AD transgenic mice to provide an indication of an AD drug candidate's potential for preventing PPCD and resulting progression towards dementia in AD. METHODS: We searched PubMed/Medline and the references of identified articles for background on the neuropathological progression of AD and its implications for drug target identification, for AD clinical trial criteria used to assess disease modification outcomes, for plasma biomarkers associated with AD and concussion/TBI, neuropathologies and especially PPCD, and for methodological critiques of AD and other neuropsychiatric clinical trial methods. RESULTS: We identified and address seven issues and highlight the Thal-Sano AD 'Time to Onset of Impairment' Design for possible applications in our clinical trials. Diverse and significant pathological cascades and indications of self-induced neuronal PPCD were found in concussion/TBI, anoxia, and AD animal models. To address the dearth of peripheral markers of AD and concussion/TBI brain pathologies and PPCD we evaluated Extracellular Vesicles (EVs) enriched for neuronal origin, including exosomes. In our concussion/TBI, anoxia and AD animal models we found evidence consistent with the presence of time-dependent PPCD and (-)-phenserine suppression of neuronal self-induced PPCD. We hence developed an extended controlled release formulation of (-)-phenserine to provide individualized dosing and stable therapeutic brain concentrations, to pharmacologically interrogate PPCD as a drug development target. To address the identified problems potentially putting any clinical trial at risk of failure, we developed exploratory AD and concussion/TBI clinical trial designs. CONCLUSIONS: Our findings inform the biomarker indication of progression of pathological targets in neurodegenerations and propose a novel approach to these conditions through neuronal protection against self-induced PPCD.