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Biomedical subjects

Sara Jo Nixon

Publications and source records attributed to Sara Jo Nixon.

16 recordsLinked to original sources

Smoking comorbidity in alcoholism: neurobiological and neurocognitive consequences.

Considerable research attests to the adverse effects of chronic smoking on cardiac, pulmonary, and vascular function as well as on increased risk for various cancers. However, comparatively little is known about the effects of chronic smoking on brain function. Although smoking rates have decreased in the developed world (they have increased in the developing world), smoking rates have been at a persistently high level in individuals with alcohol use disorders. Despite the high prevalence of comorbid chronic smoking and alcohol dependence, very few studies have addressed the separate and interactive effects that smoking and alcoholic drinking may have on neurobiology and brain function. This symposium, which took place at the annual meeting of the Research Society on Alcoholism in Santa Barbara, California, on June 29, 2005, postulates that the neurobiologic and neurocognitive abnormalities commonly described in studies of alcohol-dependent individuals are modulated by concurrent abuse of tobacco products and that brain recovery in abstinent alcoholic individuals is affected by chronic smoking. Four expert speakers and a discussant from different research disciplines focus in this symposium on the description of neurobiological and neurobehavioral effects because of concomitant drinking and smoking. Understanding the potential separate effects and interactions of chronic nicotine/smoking and alcohol consumption promotes a better understanding of specific mechanisms and neurocognitive consequences of brain injury and brain recovery with abstinence. The material presented contributes useful information to ongoing discussions about treatment strategies for these comorbid disorders and valuable educational material that can be used to affect public perception about smoking and perhaps health policy.

Alcoholism↗

Health risks of chronic moderate and heavy alcohol consumption: how much is too much?

This article presents the proceedings of a symposium held at the meeting of the International Society for Biomedical Research on Alcoholism (ISBRA) in Mannheim, Germany, in October 2004. Most of what we know about the deleterious effects of alcohol in vivo has been gleaned from studies in sober alcoholics recruited from substance abuse treatment programs. Little is known about effects of chronic drinking in the moderate or heavy range encountered in a much larger fraction of modern society. Extrapolation of information on the adverse effects of chronic drinking on organ function from clinical samples to social drinkers in the general population has to be met with great skepticism, as it may lead to wrong conclusions about the chronic effects of alcohol in social drinkers. Several recent studies suggest that moderate alcohol consumption has certain beneficial health effects, whereas heavy social alcohol consumption has recently been associated with organ abnormalities and cognitive deficits. These social drinking effects have attracted great public interest; reports of benefits of moderate drinking have also inspired inappropriate publications by the media, including misleading advertisements by the alcohol producing and distributing industry. Although adverse effects of moderate to heavy drinking on heart, liver, and cancer development have attracted attention by clinicians and researchers for some time, its compromising effects on brain and cognition have only recently been studied. This symposium brought together researchers from different disciplines, who reviewed and presented new data on consequences of social drinking in the areas of clinical neuropsychology and behavior (Drs. Nixon and Meyerhoff), neurophysiology (Dr. Nixon, Ms. De Bruin), neuroimaging (Ms. de Bruin, Dr. Meyerhoff), hepatic disease (Dr. Bode), and cancer (Dr. Seitz). The symposium aimed to clarify both the potential health benefits of moderate alcohol consumption and risks of moderate and heavy drinking on proper organ function and to provide insights and new data to practicing physicians and public health authorities for education on problem drinking.

Alcohol Drinking↗

Visual-spatial attention in alcoholics and illicit stimulant abusers: effects of nicotine replacement.

Reports of alcohol or illicit drug-related cognitive impairments have frequently disregarded the potentially confounding effects of smoking status and nicotine withdrawal on these measures. This study addressed this issue by measuring visual-spatial attention via an adaptation of the Posner paradigm in three groups of tobacco smokers: controls without a history of alcoholism or illicit drug use (n=27; 20 male), chronic alcoholics (n=22; 18 male), and illicit stimulant abusers (n=36; 21 male). Throughout testing, nicotine levels were stabilized by the double-blind administration of a high (14 or 21 mg) or low (7 mg) dose transdermal nicotine patch. A significant effect of group was observed for number of correct responses to restriction trials (F=5.48, 2/79 df; p=.006). Performance was normalized in the illicit stimulant group, and alcoholic participants exhibited superior performance relative to both illicit stimulant abusers (p=.002) and controls (p=.01). These findings support the hypothesis that nicotine may have a compensatory or normalizing effect on attentional functions in substance abusers. Whether these results reflect the central nervous system-activating effects of nicotine or merely alleviation of nicotine withdrawal is a topic of ongoing research.

Administration, Cutaneous↗

An empirical assessment of post-treatment alcohol consumption.

Substance abuse treatment programs have long contended that any post-treatment alcohol use is indicative of relapse. Recent studies, however, suggest more inclusive definitions. Zweben and Cisler (1996, 1999) consider both the drinking quantity and negative drinking consequences. Their proposed cutoffs integrate the 1995 NIAAA guidelines for sensible and high risk drinking levels with the objective assessment of drinking-related consequences into the definition of relapse. Our study applied this model to a group of detoxified alcoholics in a post-treatment followup project. We asked if: (1) Zweben and Cisler's drinking categories could be found in our sample; (2) whether subgroups defined by post-treatment drinking patterns differed with respect to their pre-treatment alcohol consumption levels, years of alcoholic drinking and drinking related problems; and (3) whether post-treatment drinking patterns were associated with differential psychosocial functioning at followup. Thirteen percent of the total sample (N=61) was found to meet Zweben and Cisler's moderate drinking category; 34% were abstinent, 27% heavy drinkers and 13 participants (26%) were unclassifiable. At treatment completion (T1), those who became moderate drinkers reported higher levels of self-confidence, but were otherwise similar to both abstainers and heavy drinkers. At followup (T2), approximately 1 year after initial testing (T1), groups differed on measures of emotional discharge, avoidance and logical coping skills and information seeking, suggesting a possible association between post-treatment drinking patterns and psychosocial functioning.

Adolescent↗

Substance abuse-related P300 differences in response to an implicit memory task.

The current study examined electrophysiological measures of cognitive efficiency in alcoholics and controls using a negative priming paradigm derived from DeSchepper and Treisman (J. Exp. Psychol. Learn. Mem. Cog. 22 (1996) 27). In this task, sets of novel shapes were presented: Two overlapping green and red shapes on the left and a single white shape on the right. Participants were instructed to ignore the red shape, but to determine whether the green shape was the same as or different from the white shape. On primed trials, previously red (to be ignored; i.e., irrelevant) shapes became green (relevant) shapes in a second component of the task. Participants who were capable of ignoring irrelevant stimuli were expected to experience more difficulty in the primed condition. Therefore, we predicted that, if alcohol-related impairment in cognitive efficiency is due to inability to respond "appropriately" (i.e., ignore irrelevant stimuli), alcoholics would experience less negative priming than normal controls. Both amplitude and latency of the P300 component of the event-related potential were measured in response to each trial condition. Using a 2 x 2 (group x condition) ANOVA with repeated conditions, a significant pattern of group x condition interactions was observed at right frontal, F4 (p=.05) and central parietal, Pz (p=.03) electrode sites on measures of P300 amplitude. A significant group x condition latency interaction was observed at the central parietal electrode, Pz (p=.006). Overall, controls exhibited increased P300 amplitude and latency in response to negatively primed trials. As predicted, alcoholics did not demonstrate this pattern, a finding consistent with alcohol-related cognitive inefficiency.

Adult↗

Musical skill in dementia: a violinist presumed to have Alzheimer's disease learns to play a new song.

Previous studies have described patients with possible or probable Alzheimer's disease (AD) who continued to play familiar songs skillfully, despite their dementias. There are no reports about patients with dementia who successfully learned to play new songs, and two papers describe failures of patients with AD to learn to play a new song although they continued to play familiar songs competently. In the present paper we describe a moderately demented patient (SL) with probable AD who learned to play a song (Cossackaya!) on the violin that was published after the apparent onset of his dementia. He showed modest retention of the song at delays of 0 and 10 minutes. This contrasts with his profound disturbance in both recall and recognition on other anterograde memory tests (word lists, stories, figures, environmental sounds, sounds of musical instruments), and marked impairment on measures of remote memory (famous faces, autobiographical memory). SL showed milder deficits in confrontation naming, verbal fluency and attention, but no dyspraxia or aphasic comprehension deficits. Except for the Block Design test, his visuospatial skills were intact. SL's learning of the new song in the absence of any evidence of episodic memory is reminiscent of patients with temporal lobe amnesia who show better memory for song melody than for lyrics or verse, although his retention was not as good.

Aged↗

Cognitive efficiency in stimulant abusers with and without alcohol dependence.

BACKGROUND: Although previous studies have found stimulant (i.e., cocaine, methamphetamine) abusers and alcoholics to have neuropsychological deficits, research examining which cognitive abilities are most affected by concurrent exposure to these substances is lacking. To address this issue, detoxified men and women who met criteria for dependence of (a) alcohol only (ALC) (n = 15); (b) stimulants only (STIM) (n = 15); and (c) both alcohol and stimulants (A/STIM) (n = 15) were compared with age- and education-matched community controls (n = 15). METHODS: Tasks that measured visual spatial skills, problem-solving and abstraction, short-term memory, cognitive flexibility, and gross motor speed were administered to participants. For each test, both speed and accuracy were assessed and an efficiency ratio (accuracy/time) was derived. Based on an average of these efficiency ratios, an overall performance index of cognitive efficiency was obtained. RESULTS: Overall, controls performed more efficiently than all other groups. However, they were statistically significantly better only in relation to the A/STIM and STIM groups (p < 0.01). Individual comparisons revealed that the ALC group performed significantly better than the STIM group, although the ALC group did not differ from either the control or A/STIM groups (p </= 0.05). This pattern of results was relatively consistent across the individual subtests of problem-solving/abstraction, short-term memory, and cognitive flexibility. CONCLUSIONS: As expected, substance abuse was associated with cognitive inefficiency. More importantly, these findings suggest that the cognitive effects of chronic stimulant abuse are not additive with those of alcohol abuse. That is, singly addicted stimulant abusers demonstrated similar or greater neurocognitive impairments than individuals who abuse alcohol and stimulants concurrently. The reason for this pattern is speculative but may be attributed to alcohol's opposing actions on cerebrovascular effects brought on by stimulant abuse.

Adult↗

Alcohol, estrogen replacement therapy, and visuospatial processes in postmenopausal women.

BACKGROUND: Studies suggest that moderate drinking may benefit cognition and the effect may favor women. This study investigated effects of moderate drinking on visuospatial functioning in postmenopausal women. Visuospatial processes are sensitive to alcohol abuse and are thought to be sensitive to hormonal fluctuations. Three questions were posed in order to: explore visuospatial processes in moderate-drinking and abstaining postmenopausal women, assess visuospatial differences in women using no estrogen replacement therapy (No-ERT), ERT alone (ERT-only), and ERT with progestin (ERT+Pro), and identify alcohol/ERT interactions associated with visuospatial performance. METHODS: Two hundred fourteen postmenopausal women participated (75 No-ERT; 63 ERT-only; 76 ERT+Pro. All were moderate drinkers or teetotalers and all received the Block Design test from the Wechsler Adult Intelligence Scale-Revised. A raw score was calculated and progress at 30-sec intervals was assessed. RESULTS: ANOVA revealed an alcohol main effect [F(3,202) = 4.74; p < 0.004] on 60- to 120-sec change scores. Teetotalers had significantly smaller change scores (less improvement) compared with all levels of drinkers. ANOVA on design 9 (the most difficult trial) revealed an ERT main effect [F(3,202) = 4.37; p < 0.02]. ERT nonusers scored significantly lower than ERT-only and ERT+Pro groups. A design 9 trend toward an alcohol x ERT interaction was noted [F(6,202) = 1.93; p < 0.08], and a design 9 time x alcohol interaction was revealed [F(6,404) = 2.65; p < 0.02]. CONCLUSIONS: These data suggest that moderate drinking may be positively associated with visuospatial processes in postmenopausal women. They also suggest that ERT, alone and with progestin, is positively associated with visuospatial processes, but only when the task is difficult. These findings support Kaplan's assertion that subtle performance deficits may not be detectible with traditional endpoint measures. A provocative alcohol x ERT trend suggests that alcohol consumption should be considered in studies of ERT effects on cognitive ability.

Aged↗

Semantic processing in alcoholics with and without antisocial symptomatology.

OBJECTIVE: Chronic alcoholics with a comorbid diagnosis of antisocial personality (ASP) symptomatology often exhibit early onset, severe course, and poor treatment outcomes. In addition, antisocial characteristics have been associated with a variety of cognitive deficits, including abnormalities of semantic processing, a deficit also found in alcoholics. Using the N400 task, this study investigated whether comorbid ASP symptomatology in alcoholics and community controls contributes to deficits in cognitive efficiency. METHOD: The N400 component of the event-related potential was elicited in detoxified alcoholics (n = 71; 56 male) and community controls (n = 36; 22 female) by sentences with congruent, related/incongruent or unrelated/incongruent terminal words. Difference waveforms were derived, and both amplitude and latency measures were obtained. Antisocial personality symptomatology was assessed using the ASP section of the Diagnostic Interview Schedule IV. RESULTS: Data were analyzed via linear regression using alcoholism, ASP positive (ASP+) status and their interaction term as predictors of N400 amplitude and latency. Significant latency findings were noted in the related/incongruent sentence condition. Increased N400 latency was predicted by ASP+ status at electrode site Pz (p = .01). The interaction of alcoholism and ASP+ status predicted increased N400 latency at electrode site P4 (p = .009), with ASP+ alcoholics demonstrating the greatest latency. CONCLUSIONS: The presence of N400 latency differences in response to related/incongruent semantic information in the current study differs from previous findings in studies of chronic alcoholism that do not account for ASP. These data suggest that antisocial personality disorder and alcoholism may affect cognitive function via different underlying mechanisms.

Adult↗

Neurophysiological efficiency in male and female alcoholics.

Chronic alcoholics often exhibit impairment in behavioral indicators of cognitive efficiency. However, potential neurophysiological correlates of this deficit are understudied. To examine this function, semantic expectancy was measured by recording the N400 component of the event-related potential (ERP), which is elicited by incongruent semantic information. Abstinent alcoholics, 21-45 days sober (n = 26; 12 males, 14 females), as well as age and education equated community controls (n = 26; 12 males, 14 females), were instructed to read silently 218 sentences ending with either congruent, related/incongruent, or unrelated/incongruent terminal words. Difference waveforms to the terminal word were derived, and amplitude and latency measures of the most negative peak between 300 and 600 ms were obtained. Electrode sites included the midline sites, Fz, Cz, and Pz; the temporal sites T3 and T4; and parietal sites P3 and P4. Significant group effects in amplitude were observed for the difference waveform under the unrelated/incongruent condition at T3, T4, and P4 (P < or = .05). Measures at P3, Pz, Fz, and Cz approached significance (P < or = .15). Although the overall pattern did not change when regression techniques were used to control for age, only the T4 site retained significance (P < or = .05). Across all electrode sites, alcoholics produced reduced N400 amplitudes relative to community controls. Latency was unaffected. There were no group effects for amplitude or latency measures in the related/incongruent condition. These data are consistent with the hypothesis that alcoholics suffer from a subtle deficiency in neurophysiologically based cognitive efficiency which renders them less likely to respond appropriately to irrelevant information.

Adult↗

Body handlers after terrorism in Oklahoma City: predictors of posttraumatic stress and other symptoms.

Posttraumatic stress and depressive symptoms were assessed in 51 body handlers after Oklahoma City's 1995 terrorist bombing. Although many handlers were inexperienced and knew someone killed, symptoms were low postdisaster and decreased significantly after 1 year. Higher symptomatology and seeking mental health treatment correlated with increases in alcohol use and new physical problems but not with demographics, exposure, or experience. Four respondents with the highest posttraumatic stress symptoms at both time points reported high physical and alcohol use problems and mental health treatment use, suggesting that these should be carefully assessed in body handlers postdisaster. Coping techniques are described, as well as possible reasons for unexpected resilience in the majority.

Adaptation, Psychological↗

Exposure and peritraumatic response as predictors of posttraumatic stress in children following the 1995 Oklahoma City bombing.

Studies have demonstrated a positive relationship between exposure and posttraumatic stress, but one's subjective appraisal of danger and threat at the time of exposure may be a better predictor of posttraumatic stress than more objective measures of exposure. We examined the role of peritraumatic response in posttraumatic stress reactions in over 2,000 middle school children 7 weeks after the 1995 Oklahoma City, Oklahoma, bombing. While many children reported hearing and feeling the blast and knowing direct victims, most were in school at the time of the explosion and therefore were not in direct physical proximity to the incident. Physical, interpersonal, and television exposure accounted for 12% of the total variance in our measure of posttraumatic stress when peritraumatic response was ignored. Peritraumatic response and television exposure accounted for 25% of the total variance, and physical and interpersonal exposure were not significant in this context. These findings suggest the importance of peritraumatic response in children's reactions to terrorism. These early responses can be used to help determine which children may experience difficulty over time.

Adolescent↗

Neurological basis of deficits in affective prosody comprehension among alcoholics and fetal alcohol-exposed adults.

Affective prosody is a nonlinguistic aspect of language that conveys emotions and attitudes during discourse. In this study the neurological basis of affective prosodic comprehension (APC) dysfunction in alcoholics (ALC) and fetal alcohol-exposed adults (FAexp) was explored. Subjects were previously tested for APC by use of the Aprosodia Battery, including 9 right-brain-damaged and 10 left-brain-damaged subjects. ALC and FAexp subjects were significantly less accurate than control subjects in APC, and scored similarly to patients with focal brain lesions. The specific APC impairment found in ALC and FAexp may be a consequence of both callosal and right cortical dysfunction or damage.

Adult↗

A comparison of substance abuse among female offender subtypes.

The relationship between substance abuse and female criminal offending has been understudied. To aid in clarification of this relation, substance use histories of female offender subtypes were compared. Participants were 152 female prison inmates subgrouped on the basis of offense category: violent (n = 79), property (n = 39), and drug (n = 34). As hypothesized, substance use histories differed across offender subgroups. Violent offenders were most clearly distinguished from other offender subgroups. The data provide evidence linking alcohol, combined cocaine and alcohol, and marijuana misuse with serious violent offending among women and show that violent offenders, compared with other offender subgroups, perceive less association between alcohol consumption and alcohol-related negative consequences.

Adult↗

Case finding and mental health services for children in the aftermath of the Oklahoma City bombing.

The 1995 Oklahoma City bombing killed 168 people, including 19 children, and injured hundreds more. Children were a major focus of concern in the mental health response. Most services for them were delivered in the Oklahoma City Public Schools where approximately 40,000 students were enrolled at the time of the explosion. Middle and high school students in the Oklahoma City Public Schools completed a clinical assessment 7 weeks after the explosion. The responses of 2720 students were analyzed to explore predictors of posttraumatic stress symptomatology, functioning, and treatment contact. Posttraumatic stress symptomatology was associated with initial reaction to the incident and to bomb-related television exposure. Functional difficulty was associated with initial reaction and posttraumatic stress symptomatology. Only 5% of the students surveyed had received counseling. There was no relationship between posttraumatic stress symptomatology and counseling contact for students with the highest levels of posttraumatic stress. Implications for school-based services are discussed.

Child↗