Biomedical subjects

Krista Lisdahl Medina

Publications and source records attributed to Krista Lisdahl Medina.

7 recordsLinked to original sources

PubMed2006

Effects of alcohol and combined marijuana and alcohol use during adolescence on hippocampal volume and asymmetry.

BACKGROUND: Converging lines of evidence suggest that the hippocampus may be particularly vulnerable to deleterious effects of alcohol and marijuana use, especially during adolescence. The goal of this study was to examine hippocampal volume and asymmetry in adolescent users of alcohol and marijuana. METHODS: Participants were adolescent (aged 15-18) alcohol (ALC) users (n=16), marijuana and alcohol (MJ+ALC) users (n=26), and demographically similar controls (n=21). Extensive exclusionary criteria included prenatal toxic exposure, left handedness, and psychiatric and neurologic disorders. Substance use, cognitive, and anatomical measures were collected after at least 2 days of abstinence from all substances. RESULTS: Adolescent ALC users demonstrated a significantly different pattern of hippocampal asymmetry (p<.05) and reduced left hippocampal volume (p<.05) compared to MJ+ALC users and non-using controls. Increased alcohol abuse/dependence severity was associated with increased right>left (R>L) asymmetry and smaller left hippocampal volumes while marijuana abuse/dependence was associated with increased L>R asymmetry and larger left hippocampal volumes. Although MJ+ALC users did not differ from controls in asymmetry, functional relationships with verbal learning were found only among controls, among whom greater right than left hippocampal volume was associated with superior performance (p<.05). CONCLUSIONS: Aberrations in hippocampal asymmetry and left hippocampal volumes were found for adolescent heavy drinkers. Further, the functional relationship between hippocampal asymmetry and verbal learning was abnormal among adolescent substance users compared to healthy controls. These findings suggest differential effects of alcohol and combined marijuana and alcohol use on hippocampal morphometry and the relationship between hippocampal asymmetry and verbal learning performance among adolescents.

Adolescent↗

PubMed2006

Anxiety, depression, and behavioral symptoms of executive dysfunction in ecstasy users: contributions of polydrug use.

BACKGROUND: Given ecstasy's (MDMA) potential serotonergic neurotoxicity, it is plausible that regular ecstasy users would have an elevated prevalence of behavioral executive dysfunction or mood symptoms. However, recent studies have found that the relationship between ecstasy use and psychological symptoms was no longer significant after controlling for marijuana use (e.g., Morgan et al., 2002). The goal of the present study was to examine the relationship between ecstasy exposure and self-reported executive functioning and psychological symptoms after controlling for gender, ethnicity, and other drug use. METHODS: Data were collected from 65 men and women with a wide range of ecstasy use (including 17 marijuana-using controls). Participants were administered the Frontal Systems Behavioral Scale, State-Trait Anxiety Inventory for adults, and the Beck Depression Inventory-2nd edition. RESULTS: Although 19-63% of the ecstasy users demonstrated clinically elevated psychological symptoms, frequency of ecstasy use did not predict the psychological symptoms. No gender differences or interactions were observed. CONCLUSIONS: These results revealed that, although ecstasy users demonstrate elevated levels of psychological symptoms and executive dysfunction, these symptoms are not statistically associated with their ecstasy consumption. Instead, other drug use (alcohol, marijuana, opioids, and inhalants) significantly predict psychological symptoms in this sample of polydrug users.

Affect↗

PubMed2006

Age-related changes in prefrontal white matter volume across adolescence.

Past research has suggested that white matter volume increases from childhood to adulthood; however, during adolescence, there is somewhat limited data to support this finding. In the present study, 65 typically developing adolescents underwent structural magnetic resonance imaging. Using magnetic resonance imaging, prefrontal white matter volumes were examined in relation to adolescent age and sex. Surprisingly, results suggested that prefrontal white matter volume decreased during late adolescence, particularly among the female sex. These findings are inconsistent with past research and suggest that perhaps some developmental processes in late adolescence are not yet fully explained. Possible methodological contributions and implications for the current findings are discussed.

Adolescent↗

PubMed2006

Memory functioning in polysubstance dependent women.

BACKGROUND: The vast majority of studies on polysubstance abuse or dependence have utilized male participants; therefore, the specific neuropsychological effects of polysubstance dependence in women are relatively unknown. The goal of the present study is to examine the effects of polysubstance dependence on women's verbal and visual memory ability. METHODS: Data were collected from 109 women (46 controls and 63 polysubstance dependence women who were similar in ethnic identification, education, age, and verbal ability). A series of multiple regressions were run to test whether group membership significantly predicted performance on the Benton Visual Retention Test and the California Verbal Learning Test after controlling for important demographic characteristics. RESULTS: The primary results indicated that the polysubstance dependent women had significantly poorer verbal learning ability (ranging from p<.005 to .05) than the control group, while no differences were found in visual memory ability. Further, significant bivariate relationships were observed between frequency of alcohol and cocaine use and verbal learning, delayed recall, and recognition ability. CONCLUSIONS: The results confirm that polysubstance dependence is associated with deficient encoding of verbal information. In addition, past year frequent use of alcohol and cocaine was associated with more severe deficits in delayed recall and recognition ability among polysubstance dependent women at the bivariate level.

Adult↗

PubMed2005

Ecstasy (MDMA) exposure and neuropsychological functioning: a polydrug perspective.

Ecstasy (MDMA) is a popular drug that can act as a selective serotonin neurotoxin in several species. The goal of the present study was to examine the relationship between ecstasy exposure and cognitive functioning after controlling for other drug use and demographic variables. Furthermore, we assessed whether gender was a moderator of the relationship between cognitive functioning and ecstasy use. Data were collected from 31 men and 34 women with a wide range of ecstasy use (17 marijuana users with no ecstasy use and 48 ecstasy users ranging from low to heavy use). Participants were interviewed and administered a battery of neuropsychological tests. The primary finding was that ecstasy exposure was significantly related to poorer verbal learning and memory ability in a dose-dependent manner, while no such relationship was observed between ecstasy exposure and executive functioning or attentional ability. Gender was found to significantly moderate the relationship between ecstasy consumption and design fluency. These results suggest primary memory dysfunction among abstinent recreational ecstasy users. This finding is consistent with reports of hippocampal vulnerability, particularly among heavy users.

Adolescent↗

PubMed2004

Cognitive functioning and length of abstinence in polysubstance dependent men.

To date, there are few large-scale studies that have examined the relationship between duration of abstinence and cognitive functioning in polysubstance-dependent individuals. Existing large-scale studies of polysubstance abusers have reported only minimal recovery of cognitive functioning with abstinence [Arch. Gen. Psychiatry 35 (1978) 1063]. The goal of this study is to test whether length of abstinence (1 day and 14 months) is related to cognitive ability in a large cross-sectional sample of men recovering from dependence on at least two drugs (N = 207). A series of Poisson and linear regressions were run to test whether length of abstinence is associated with neuropsychological performance while controlling for demographic variables, raw Vocabulary score, drug use, and dependency. The primary finding is that increasing length of abstinence was not statistically associated with superior neuropsychological ability. This suggests that the abuse of multiple substances potentially produces long-lasting neuropsychological impairment with minimal recovery of functioning over a 1-year period.

Adult↗

PubMed2002

Self-administration of alcohol before and after a public speaking challenge by individuals with social phobia.

K. Abrams, M. Kushner, K. Medina, and A. Voight (2001) showed that alcohol attenuates social anxiety symptoms in socially phobic individuals. This article examines whether social anxiety symptoms can lead to increased alcohol use in this same population. Forty-four individuals with social phobia attended 2 laboratory sessions, spaced 1 week apart, in groups of approximately 10. Participants underwent a social anxiety challenge during 1 session and a control task during the other. Half of the sample self-administered alcohol immediately before, and half immediately after, these 2 activities. As predicted, participants consumed more alcohol following the anxiety challenge than following the control task; however, the opposite pattern was evidenced for drinking preceding [corrected] the 2 activities. These findings add to an understanding of why social phobia and alcohol problems tend to co-occur.

Adaptation, Psychological↗