Hollis C Karoly

Dr. Hollis C Karoly

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Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 May 2015 in Journal of Pediatric Psychology
Verified
Journal Article
Open access
PDF file
HKHollis C Karoly
Hollis C Karoly
Tiffany Jean Lee CallahanTiffany Jean Lee Callahan
Tiffany Jean Lee Callahan
SSSarah J. Schmiege
Sarah J. Schmiege
SESarah W. Feldstein Ewing
Sarah W. Feldstein Ewing
Objective In the United States, Hispanic adolescents are at elevated risk for negative outcomes related to risky sexual behavior. To evaluate potential protective factors for this group, we examined the fit of the Hispanic Paradox for sexual behavior among high-risk youth and the moderating role of parent monitoring. Method We enrolled 323 justice-involved Hispanic youth (73% male; mean age 16 years), and measured generational status, parent monitoring (monitoring location, who children spend time with outside of school, family dinner frequency), and sexual risk behavior. Results There were no main effects for generational status on sexual behavior. Parent monitoring of location moderated the relationship between generational status and sexual behavior, such that greater monitoring of location was associated with less risky sexual behavior, but only for youth second generation and above. Conclusions Rather than direct evidence supporting the Hispanic Paradox, we found a more nuanced relationship for generational status in this sample.

1 January 2012 in Journal of Cancer Epidemiology
Verified
Journal Article
Open access
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HKHollis C Karoly
Hollis C Karoly
CSCourtney J Stevens
Courtney J Stevens
RMRenee E. Magnan
Renee E. Magnan
NHNicole Harlaar
Nicole Harlaar
KHKent E. Hutchison
Kent E. Hutchison
ABAngela D. Bryan
Angela D. Bryan
Objective. To determine whether genetic variants suggested by the literature to be associated with physiology and fitness phenotypes predicted differential physiological and subjective responses to a bout of aerobic exercise among inactive but otherwise healthy adults.Method. Participants completed a 30-minute submaximal aerobic exercise session. Measures of physiological and subjective responding were taken before, during, and after exercise. 14 single nucleotide polymorphisms (SNPs) that have been previously associated with various exercise phenotypes were tested for associations with physiological and subjective response to exercise phenotypes.Results. We found that two SNPs in theFTOgene (rs8044769 and rs3751812) were related to positive affect change during exercise. Two SNPs in theCREB1gene (rs2253206 and 2360969) were related to change in temperature during exercise and with maximal oxygen capacity (VO2max). TheSLIT2SNP rs1379659 and theFAM5CSNP rs1935881 were associated with norepinephrine change during exercise. Finally, theOPRM1SNP rs1799971 was related to changes in norepinephrine, lactate, and rate of perceived exertion (RPE) during exercise.Conclusion. Genetic factors influence both physiological and subjective responses to exercise. A better understanding of genetic factors underlying physiological and subjective responses to aerobic exercise has implications for development and potential tailoring of exercise interventions.

1 December 2015 in Developmental Cognitive Neuroscience
Verified
Journal Article
Open access
HKHollis C Karoly
Hollis C Karoly
ABAngela D. Bryan
Angela D. Bryan
BWBarbara J. Weiland
Barbara J. Weiland
AMAndrew Mayer
Andrew Mayer
ADAndrew Dodd
Andrew Dodd
SESarah W. Feldstein Ewing
Sarah W. Feldstein Ewing
Numerous questions surround the nature of reward processing in the developing adolescent brain, particularly in regard to polysubstance use. We therefore sought to examine incentive-elicited brain activation in the context of three common substances of abuse (cannabis, tobacco, and alcohol). Due to the role of the nucleus accumbens (NAcc) in incentive processing, we compared activation in this region during anticipation of reward and loss using a monetary incentive delay (MID) task. Adolescents (ages 14-18; 66% male) were matched on age, gender, and frequency of use of any common substances within six distinct groups: cannabis-only (n=14), tobacco-only (n=34), alcohol-only (n=12), cannabis+tobacco (n=17), cannabis+tobacco+alcohol (n=17), and non-using controls (n=38). All groups showed comparable behavioral performance on the MID task. The tobacco-only group showed decreased bilateral nucleus accumbens (NAcc) activation during reward anticipation as compared to the alcohol-only group, the control group, and both polysubstance groups. Interestingly, no differences emerged between the cannabis-only group and any of the other groups. Results from this study suggest that youth who tend toward single-substance tobacco use may possess behavioral and/or neurobiological characteristics that differentiate them from both their substance-using and non-substance-using peers.

13 September 2019 in Journal of Dual Diagnosis
Verified
Journal Article
Closed access
HKHollis C Karoly
Hollis C Karoly
JRJ. Megan Ross
J. Megan Ross
JEJarrod M. Ellingson
Jarrod M. Ellingson
SESarah W. Feldstein Ewing
Sarah W. Feldstein Ewing
Objective: Amidst the evolving policy surrounding cannabis legalization in the United States, cannabis use is becoming increasingly prevalent as perceptions of harm decrease, particularly among adolescents. Cannabis and alcohol are commonly used by adolescents and are often used together. However, developmental research has historically taken a “single substance” approach to examine the association of substance use and adolescent brain and behavior rather than examining co-(or poly-substance) use of multiple substances, such as cannabis and alcohol. Thus, the acute effects of cannabis and alcohol, and the impact of co-use of cannabis and alcohol on the adolescent brain, cognitive function and subsequent psychosocial outcomes remains understudied. This narrative review aims to examine the effects of cannabis and alcohol on adolescents across a number of behavioral and neurobiological outcomes. Methods: The PubMed and Google Scholar databases were searched for the last 10 years to identify articles reporting on acute effects of cannabis and alcohol administration, and the effects of cannabis and alcohol on neuropsychological, neurodevelopmental, neural (e.g., structural and functional neuroimaging), and psychosocial outcomes in adolescents. When adolescent data were not available, adult studies were included as support for potential areas of future direction in adolescent work. Results: Current studies of the impact of cannabis and alcohol on adolescent brain and behavior have yielded a complicated pattern. Some suggest that the use of cannabis in addition to alcohol during adolescence may have a “protective” effect, yielding neuropsychological and structural brain outcomes that are better than those for adolescents who use only alcohol. However, other adolescent studies suggest that cannabis and alcohol co-use is associated with negative health and social outcomes such as poorer academic performance and impaired driving. Conclusion: Variation in study methodologies, policy-level limitations and our limited understanding of the developmental neurobiological effects of cannabis preclude the straightforward interpretation of the existing data on adolescent cannabis and alcohol use. Further research on this topic is requisite to inform the development of effective intervention and prevention programs for adolescent substance users, which hinge on a more comprehensive understanding of how cannabis—and its intersection with alcohol—impacts the developing brain and behavior.

5 December 2019 in Alcohol, Clinical and Experimental Research
Verified
Journal Article
Closed access
PDF file
HKHollis C Karoly
Hollis C Karoly
RMRaeghan Mueller
Raeghan Mueller
LBL Cinnamon Bidwell
L Cinnamon Bidwell
KHKent E. Hutchison
Kent E. Hutchison

1 February 2022 in Cannabis & Cannabinoid Research
Verified
Journal Article
Open access
HKHollis C Karoly
Hollis C Karoly
MMMichael A. Milburn
Michael A. Milburn
ABAshley Brooks-Russell
Ashley Brooks-Russell
MBMary B Brown
Mary B Brown
JSJessica Streufert
Jessica Streufert
LBL Cinnamon Bidwell
L Cinnamon Bidwell
Background: Recently increased access to cannabis products in the United States has been associated with increased rates of driving after cannabis use. Although numerous studies indicate that cannabis impairs psychomotor and neurocognitive functions that can affect driving ability, the determination of cannabis-impaired driving risk is complicated by the extent to which frequent cannabis users develop tolerance to THC's subjective, cognitive, and psychomotor effects, and by the fact that there is no validated behavioral or biological marker of recent cannabis use or cannabis-related impairment. This study examined the psychomotor impairment-related effects experienced by frequent cannabis users in Colorado after naturalistic consumption of smoked cannabis, both immediately and 1 h postuse. Results were then validated in a smaller replication sample from Washington state. Methods: In the primary Colorado study, participants ( n =70) used the DRUID ® mobile app, a brief measure of psychomotor and cognitive domains that are sensitive to the effects of cannabis. First, participants used DRUID to establish a sober baseline impairment score. During a second appointment, they used DRUID at three time points: preuse, immediately after acutely using cannabis, and 1 h postuse. In the Washington replication sample, participants ( n =39) used DRUID before acute cannabis consumption and then every half hour for 2.5 h. Results: In both studies, peak DRUID impairment effects were seen immediately after cannabis use, with recovery of performance at 1 h postuse. Specifically, significant quadratic effects of time emerged for both studies (Colorado study: ( β =−0.935, SE =0.204, p <0.001); Washington study: β =3.0299, SE =1.3085, p <0.01). Domain-specific effects were tested in the larger Colorado study and were observed for reaction time within a complex divided attention task and a postural-stability balance task. Conclusions: These findings demonstrate that psychomotor impairment emerges immediately after acute cannabis use even in regular users, but decreases significantly 1 h postuse. These results underscore the potential utility of the DRUID app for assessing acute cannabis-related psychomotor impairment. Further research is needed to explore whether the DRUID app and/or the specific psychomotor functions it assesses might serve as a tool for measuring cannabis-related driving impairment. Clinical trials registration number for the Colorado Study: NCT03522103.