Papers by George Alexopoulos
The American Journal of Geriatric Psychiatry, 2021
Introduction: While brain structure during adolescence and early adulthood has been relatively we... more Introduction: While brain structure during adolescence and early adulthood has been relatively well characterized in bipolar disorder (BD), it is still unclear how the brain's structure is affected by the illness in later life, and whether age of onset may influence age-related changes. Methods: High resolution structural magnetic resonance images were acquired at 3 Tesla in 103 individuals with BD and 98 healthy controls (HC), ages 40 to 79 years. Categorical group comparisons (BD vs. HC), and analyses for group differences in age-related patterns, were performed for cortical thickness and grey matter volume. The BD group was also subdivided by age of first mood symptom onset, being either age 25 years and over (adult-onset, n=21) or below age 25 years (adolescent-onset, n=82), and the BD subgroups were compared to controls in a three-way analysis. Results: Compared to the HC group, the overall BD group was characterized by lower cortical thickness within the insula and parahippocampus regions (pcorrected= 0.0054), and lower grey matter volume within the hippocampus, thalamus and putamen (pcorrected = 0.001). Significant age-related differences were not detected between the overall BD group and HC group. However, when individuals with BD were divided by those with adolescent or adult onset of the illness, the adult-onset BD subgroup showed significant age-related declines in insula and parahippocampal thickness, and hippocampal, thalamic and striatal grey matter volume, compared to the early-onset BD subgroup and HC group (p = 0.021). Conclusions: The findings support structural abnormalities within the insula, parahippocampus, hippocampus, thalamus and striatum in adults with BD ages 40-79 years. Age-related decreases within the insula, parahippocampus and hippocampus may occur particularly in individuals with BD with onset after the age of 25 years. The results suggest that individuals with later onset of BD may be at a greater risk for age-related abnormalities in brain structure in brain systems that subserve emotional and cognitive processes.
After the introduction of the new tobacco regime, many regions in Greece, formerly specialized in... more After the introduction of the new tobacco regime, many regions in Greece, formerly specialized in tobacco cultivation, are now facing serious threats of economic and social decline. Sheep farming is considered by many analysts as a viable alternative to tobacco. This study analyses the financial performance of sheep production and the risk that producers are taking. Through a stochastic efficiency analysis with respect to a function we explore the economic viability of conventional and organic sheep farming; key factors determining the economic outcome of these activities are also investigated. Both organic and conventional sheep farming appear as viable alternatives. The viability of organic farming lies, mainly, in organic payments. Conventional farming generates a slightly lower but less uncertain net return.
Antenna and Sensor Technologies in Modern Medical Applications, 2021
Learning Health Systems, 2020
Objective: To identify depression subphenotypes from Electronic Health Records (EHRs) using machi... more Objective: To identify depression subphenotypes from Electronic Health Records (EHRs) using machine learning methods, and analyze their characteristics with respect to patient demographics, comorbidities, and medications. Materials and Methods: Using EHRs from the INSIGHT Clinical Research Network (CRN) database, multiple machine learning (ML) algorithms were applied to analyze 11 275 patients with depression to discern depression subphenotypes with distinct characteristics. Results: Using the computational approaches, we derived three depression subphenotypes: Phenotype_A (n = 2791; 31.35%) included patients who were the oldest (mean (SD) age, 72.55 (14.93) years), had the most comorbidities, and took the most medications. The most common comorbidities in this cluster of patients were hyperlipidemia, hypertension, and diabetes. Phenotype_B (mean (SD) age, 68.44 (19.09) years) was the largest cluster (n = 4687; 52.65%), and included patients suffering from moderate loss of body function. Asthma, fibromyalgia, and Chronic Pain and Fatigue (CPF) were common comorbidities in this subphenotype. Phenotype_C (n = 1452; 16.31%) included patients who were younger (mean (SD) age, 63.47 (18.81) years), had the fewest comorbidities, and took fewer medications. Anxiety and tobacco use were common comorbidities in this subphenotype. Conclusion: Computationally deriving depression subtypes can provide meaningful insights and improve understanding of depression as a heterogeneous disorder. Further investigation is needed to assess the utility of these derived phenotypes to inform clinical trial design and interpretation in routine patient care.
Biological Psychiatry, 2020
Background: Both reward sensitivity and cognitive response styles are associated with heightened ... more Background: Both reward sensitivity and cognitive response styles are associated with heightened inflammatory physiology. Consistent with the immunocognitive model of mood disorders, these characteristics might influence inflammatory
The Greek Debt Crisis, 2017
Two centuries of Greek debt emergencies highlight the traps of depending on outside financing. Si... more Two centuries of Greek debt emergencies highlight the traps of depending on outside financing. Since its autonomy in 1829, the Greek government has defaulted four times on its outside creditors, and it was safeguarded in every crisis. Firstly, this chapter demonstrates that cycles of outside crises and reliance are a perpetual topic of Greek present-day history—with rehashing designs: before the default, there is a time of substantial acquiring from remote private loan bosses. Secondly, it analyzes the period from 2008 in more detail to present and the role that the banks play in four times defaults. As reimbursement challenges emerge, foreign governments venture in, help to reimburse the private leasers, and request spending cuts and alteration programs as a condition for the authority bailout advances. Political obstruction from abroad mounts and a drawn out scene of obligation shade and monetary autarky takes after. At present, there is considerable evidence to suggest that a substantial haircut on external debt is needed to restore the economic viability of the country. Even with that, a policy priority for Greece is to reorient, to the extent possible, toward domestic sources of funding.
Biological Psychiatry, 2019
Background: Acute treatment guidelines for unipolar psychotic major depression (PD) recommend ele... more Background: Acute treatment guidelines for unipolar psychotic major depression (PD) recommend electroconvulsive therapy or the combination of antidepressant and antipsychotic medications. Unfortunately, relapse and recurrence are common. Little is known about continuation pharmacologic treatment in PD, specifically whether antipsychotic medication needs to be continued once an episode of PD responds to combination pharmacotherapy. This issue has great clinical significancepremature discontinuation of the antipsychotic medication has the potential risk of early relapse of this severe and potentially lethal disorder whereas its unnecessary continuation can expose a patient to adverse effects. Methods: STOP-PD II was a NIMH-funded, multicenter randomized placebo-controlled trial that assessed the risks and benefits of continuing antipsychotic medication in adults once the episode of PD had responded to combination treatment with an antidepressant (sertraline) and an antipsychotic (olanzapine). Results: Among 126 remitted participants, the time to relapse was significantly shorter for participants randomized to antidepressant monotherapy compared to those randomized to combination therapy (X2 ¼ 17.8, dF¼1, p< 0.0001); the frequency of relapse was 54.8% (n¼34/62) and 20.3% (n¼13/64), respectively, over 36 weeks. There was a significant difference between groups in trajectories of weight (F¼116.78, dF ¼ 1,1422, p<0.0001) and total cholesterol (F¼13.15, dF ¼ 1,311, p¼0.0003), with a decrease in these variables in the antidepressant monotherapy group and an increase in weight in the combination therapy group. The groups did not differ in the trajectory of plasma glucose. Conclusions: In this study, combination therapy was associated with a reduced risk of relapse but at the expense of ongoing weight gain.
IEEE Transactions on Microwave Theory and Techniques, 2017
The heterogeneous integration of silicon germanium (SiGe) and gallium arsenide (GaAs) technologie... more The heterogeneous integration of silicon germanium (SiGe) and gallium arsenide (GaAs) technologies is presented using a novel encapsulated packaging approach with organic laminates. The combination of unique and optimally matched interconnects for each die, and the low-loss nature of the organic substrates, provides wideband performance and system design flexibility. A hybrid receiver front-end is realized on multilayer Rogers RO3003 to demonstrate this concept, incorporating a flip-chip bonded SiGe low-noise amplifier and a ribbon-bonded GaAs mixer. The simulated 3-dB bandwidth of the receiver is 4.5-14.5 GHz with a maximum conversion gain of 1.2 dB. Measured results for the packaged module show a 4-14-GHz 3-dB bandwidth and 0.9-dB maximum conversion gain. These results validate that the package is indeed low loss and preserves system performance over the entire bandwidth. The receiver also exhibits a double side band NF min of 4 dB and a maximum P 1 dB, input of −5.5 dBm. This is the first time that heterogeneous semiconductor technologies have been integrated and encapsulated within a multilayer organic package using different interconnects for each chip to form a receiver. Moreover, the receiver achieves the widest bandwidth among heterogeneous receivers reported to date.
In a continuous changing environment where its major threats and opportunities derives from the s... more In a continuous changing environment where its major threats and opportunities derives from the severe competition, the ongoing biodiversity, the established competitive rivalry, the ‘intermediaries’ bargaining power, the agriculturally-based entrepreneurship viability depends mainly on its performance, flexibility, adaptability to managing marketing competitive strategies and innovative practices. Taken under consideration that small producers and vendors, men and women, are important actors in rural and peri-urban agricultural activities, this paper aims to identify and propose innovative marketing practices both to promote agricultural product and to connect food processing/production with marketplace conditions. Based to relevant literature and empirical researches, we investigate the above-mentioned subject analyzing the entire spectrum of the food supply chain (F.S.C.). Mainly, we split our investigation effort up to two areas of analysis: Area #1: food processing & production...
Journal of Food Agriculture and Environment
The American Journal of Geriatric Psychiatry, 1996
The authors studied elderly patients with major depression (MDD) who recovered after nortriptylin... more The authors studied elderly patients with major depression (MDD) who recovered after nortriptyline treatment to determine the relationship of affective symptoms at completion of continuation treatment to eventual MDD recurrence. Independent objective measures of depressive and anxiety symptoms were obtained before and after nortriptyline tapering. Univariate log-rank analysis demonstrated a trend for total post-discontinuation anxiety scores to predict time-to-recurrence in 12 subjects with complete data sets. Items assessing excessive worry and psychic tension (subjective anxiety) were significant predictors. No relationship was found between continuation-phase anxiety or depressive symptoms either immediately preceding or after discontinuation and course.
International Journal of Information Communication Technologies and Human Development, 2010
In the last few decades, within the rhetoric of the “information age”, there is a growing enthusi... more In the last few decades, within the rhetoric of the “information age”, there is a growing enthusiasm for the (potential) benefits of the dissemination of Information and Communication Technologies (ICTs). This is further enhanced through eGovernment projects undertaken on a worldwide scale. However, a number of issues seem to defy such optimism as far as rural areas are concerned. The critical review of such issues question the thesis that ICTs undoubtedly benefit (human) development. In particular, this paper, drawing on data from a large-scale survey in Greece, identifies the marginal effects of a series of demographic, socioeconomic and spatial characteristics, and information sources on PC and Internet use on the part of young rural inhabitants, especially farmers. The results, pointing toward an emerging intra-rural digital divide, are consequently discussed vis-à-vis eGovernment projects, from the point of view of human development.
Cardiovascular Drugs and Therapy, 1999
Summary. Intravenous amiodarone has been found useful in the emergent management of life-threatin... more Summary. Intravenous amiodarone has been found useful in the emergent management of life-threating arrhythmias. Experimental studies have shown that its electrophysiologic effects are proportional to its myocardial concentration. However, early after its intravenous administration, the extent of the concentration of amiodarone in the human myocardium, the site of its action, is not well known. This study was performed to measure
Renewable Agriculture and Food Systems, 2013
This study attempts to enrich the debate on the different forms of risk management strategies tha... more This study attempts to enrich the debate on the different forms of risk management strategies that are utilized by organic farmers and to assess the internal dynamics within the organic farming community by examining the attitudes and practices of these farmers. In particular, using a factor analysis, this study determines the attitudes of Greek farmers toward risk management strategies and focuses on the differences in risk attitudes between existing organic farmers and non-organic farmers. Second, using a probit analysis, this study characterizes the key factors that affect Greek farmers' attitudes with respect to risk management strategies. The thorough presentation of this research study provides essential information to policy-makers for understanding the factors that induce farmers to participate in organic agriculture. Moreover, the analysis of the risk management strategies that organic farmers apply is expected to offer valuable insights that will be critical for the ti...
Pharmacoepidemiology and Drug Safety, 1998
... Correspondence. Gastric adenocarcinoma in a patient under immunosuppressive and omeprazole tr... more ... Correspondence. Gastric adenocarcinoma in a patient under immunosuppressive and omeprazole treatment. Angeliki Iliopoulou MD 1,* ,; George Giannakopoulos MD 2 ,; Emella Zervoudi MD 2 ,; George Alexopoulos MD 2 ,; Stamatios Stamatelopoulos MD 2. ...
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Papers by George Alexopoulos