Biomedical subjects

F Joseph McClernon

Publications and source records attributed to F Joseph McClernon.

14 recordsLinked to original sources

PubMed2007

The effects of a low-carbohydrate ketogenic diet and a low-fat diet on mood, hunger, and other self-reported symptoms.

OBJECTIVE: To investigate the effects of weight loss diets on mood, food cravings, and other self-reported symptoms. RESEARCH METHODS AND PROCEDURES: Mood and other symptoms were evaluated by participant self-report using the Atkins Health Indicator Test (AHIT) in individuals undergoing weight loss following either a low-carbohydrate, ketogenic diet (LCKD) or a low-fat diet (LFD). Participants were 119 overweight community volunteers randomized to an LCKD or an LFD. An additional 51 participants who had completed an earlier trial contributed data for the psychometric analyses but were not included in the prospective analyses. Self-reported symptom levels on seven scales factor-analytically derived from the AHIT (negative affect, fatigue, somatic symptoms, physical effects of hunger, insomnia, hunger, and stomach problems) were acquired during 12 visits. RESULTS: After adjusting for the change in BMI over the course of the trial, participants experienced significant improvements in most symptoms regardless of diet. Diet group x visit interactions were observed for negative affect [F(9,803) = 2.30, p = 0.015] and hunger [F(9,803) = 3.62, p < 0.0002]. Examination of means indicated that the LCKD group reported less negative affect and hunger, compared with the LFD group. DISCUSSION: Regardless of diet, participants experienced significant improvement in a broad range of symptoms. Symptoms of negative affect and hunger improved to a greater degree in patients following an LCKD compared with those following an LFD. Whether these symptom changes explain the greater short-term weight loss generally experienced by LCKD followers deserves further research.

Adult↗

PubMed2006

Transdermal nicotine attenuates depression symptoms in nonsmokers: a double-blind, placebo-controlled trial.

RATIONALE: Despite established links between nicotine dependence and depression, little research has examined the effects of nicotine on depression symptoms. OBJECTIVE: This study evaluated the acute and chronic effects of transdermal nicotine in nonsmokers with baseline depression symptoms during a 4-week, double-blind, placebo-controlled trial. METHODS: Nonsmokers with scores >or=10 on the Center for Epidemiological Studies Depression scale (CES-D) were recruited from the community. Mood and cognitive performance were measured at baseline (day 0) and at 1, 8, 21, and 28 days. Participants were randomly assigned to wear a placebo or nicotine patch for 4 weeks (3.5 mg/day during weeks 1 and 4; 7 mg/day during weeks 2 and 3). The final sample consisted of 11 nonsmokers with a mean baseline CES-D score of 27.36 (SD=10.53). RESULTS: Salivary nicotine levels indicated the majority of participants were compliant with treatment. Acute nicotine did not alter mood. After adjusting for baseline values, chronic nicotine resulted in a significant decline in CES-D scores at day 8 (3.5 mg/day), but returned to placebo levels by the last visit. This return to baseline levels was coincident with a decrease in nicotine administration from 7 to 3.5 mg/day. A similar trend for improved response inhibition as measured by the Conners Continuous Performance Task was also observed. Reported side effects were infrequent and minimal. CONCLUSION: These findings suggest a role for nicotinic receptor systems in the pathophysiology of depression and that nicotinic compounds should be evaluated for treating depression symptoms.

Administration, Cutaneous↗

PubMed2006

Enhanced cue-elicited brain activation in African American compared with Caucasian smokers: an fMRI study.

Current evidence indicates that, although African Americans (AA) are more likely to attempt to quit smoking than Caucasians (CC) in any given year, success rates are lower for AA. However, factors contributing to these differences are not well known. In order to explore potential factors, this study assessed differences in attention to smoking cues between ethnic groups. Participants underwent morning functional magnetic resonance imaging scanning while viewing images of AA models and CC models who were either smoking (smoking cues) or engaging in everyday activities (neutral cues), interspersed with a fixation baseline period. The study was conducted at the Hoglund Brain Imaging Center of the University of Kansas Medical Center in Kansas City, KS. We studied 17 smokers (eight AA, nine CC) after 12-hour abstinence and 17 non-smokers (eight AA, nine CC) matched by age, gender, years of education, and handedness. The AA and CC smoking groups were also matched for number of cigarettes smoked per day. All results are P < 0.01, corrected for whole brain. There was a strong ethnicity by condition interaction among smokers in several a priori regions of interest. AA smokers showed a greater increase in response to smoking (versus neutral cues) than CC smokers in the medial prefrontal cortex, right lateral orbitofrontal cortex, and bilateral ventrolateral prefrontal cortex. In smoking versus baseline contrasts, additional areas of greater activation were found in AA, including the right amygdala and left caudate nucleus. No significant differences in cue-elicited brain activation were found between AA and CC non-smokers. These preliminary findings demonstrate variation in brain activation in response to smoking cues between AA and CC smokers in structures known to be associated with nicotine addiction. Differences in neural response may reflect fundamental differences in attention to smoking cues, which may in turn contribute to differences in effectiveness of nicotine dependence treatments among ethnic populations.

Adult↗

PubMed2005

Nicotinic effects on cognitive function: behavioral characterization, pharmacological specification, and anatomic localization.

RATIONALE: Nicotine has been shown in a variety of studies in humans and experimental animals to improve cognitive function. Nicotinic treatments are being developed as therapeutic treatments for cognitive dysfunction. OBJECTIVES: Critical for the development of nicotinic therapeutics is an understanding of the neurobehavioral bases for nicotinic involvement in cognitive function. METHODS: Specific and diverse cognitive functions affected by nicotinic treatments are reviewed, including attention, learning, and memory. The neural substrates for these behavioral actions involve the identification of the critical pharmacologic receptor targets, in particular brain locations, and how those incipient targets integrate with broader neural systems involved with cognitive function. RESULTS: Nicotine and nicotinic agonists can improve working memory function, learning, and attention. Both alpha4beta2 and alpha7 nicotinic receptors appear to be critical for memory function. The hippocampus and the amygdala in particular have been found to be important for memory, with decreased nicotinic activity in these areas impairing memory. Nicotine and nicotinic analogs have shown promise for inducing cognitive improvement. Positive therapeutic effects have been seen in initial studies with a variety of cognitive dysfunctions, including Alzheimer's disease, age-associated memory impairment, schizophrenia, and attention deficit hyperactivity disorder. CONCLUSIONS: Discovery of the behavioral, pharmacological, and anatomic specificity of nicotinic effects on learning, memory, and attention not only aids the understanding of nicotinic involvement in the basis of cognitive function, but also helps in the development of novel nicotinic treatments for cognitive dysfunction. Nicotinic treatments directed at specific receptor subtypes and nicotinic cotreatments with drugs affecting interacting transmitter systems may provide cognitive benefits most relevant to different syndromes of cognitive impairment such as Alzheimer's disease, schizophrenia, and attention deficit hyperactivity disorder. Further research is necessary in order to determine the efficacy and safety of nicotinic treatments of these cognitive disorders.

Alzheimer Disease↗

PubMed2005

Association between smoking and attention-deficit/hyperactivity disorder symptoms in a population-based sample of young adults.

CONTEXT: Attention-deficit/hyperactivity disorder (ADHD) has been associated with increased risk of smoking, and some studies have suggested that inattentive symptoms specifically may underlie this risk. Few studies, however, have examined ADHD symptoms in nonclinical samples to determine the extent to which the number of symptoms-independent of the full diagnosis-confer risk for smoking-related outcomes. OBJECTIVE: To evaluate the relation between smoking-related variables and the number of retrospectively reported ADHD inattentive and hyperactive/impulsive symptoms in a population-based sample of young adults. DESIGN, SETTING, AND PARTICIPANTS: The study population consists of 15 197 eligible participants from wave III of the National Longitudinal Study of Adolescent Health, a nationally representative sample of adolescents followed from 1995 to 2002. MAIN OUTCOME MEASURES: Logistic regression was used to examine the relation between self-reported ADHD symptoms and the lifetime likelihood of being a regular smoker, defined by having smoked at least 1 cigarette a day for 30 days. For individuals reporting regular smoking, we also examined the extent to which ADHD symptoms predicted age at onset of regular smoking and number of cigarettes smoked. RESULTS: A linear relation was identified between the number of self-reported inattentive and hyperactive/impulsive symptoms and smoking outcome measures (P<.001 for each symptom domain). Controlling for demographic and conduct disorder symptoms, each reported inattention and hyperactivity/impulsivity symptom significantly increased the likelihood of ever regular smoking (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.08-1.14 and OR, 1.16; 95% CI, 1.13-1.19, respectively). For those reporting lifetime regular smoking, reported symptoms decreased the estimated age at onset and increased the number of cigarettes smoked. CONCLUSIONS: Self-reported ADHD symptoms were found to be associated with adult smoking outcome variables in this nationally representative sample, providing further evidence of a likely link between ADHD symptoms and risk for tobacco use.

Adolescent↗

PubMed2005

The effects of trauma recall on smoking topography in posttraumatic stress disorder and non-posttraumatic stress disorder trauma survivors.

Smoking topography was measured in trauma survivors with and without posttraumatic stress disorder (PTSD) after recalling trauma-related and neutral experiences. Analysis of covariance was performed on puff topography and mood measures using nicotine dependence scores and current major depressive disorder as covariates. Puff volumes were higher in the PTSD group than in the non-PTSD group. The PTSD group exhibited stable puff onset intervals while the non-PTSD group exhibited significantly shorter intervals following trauma recall. These findings support a "ceiling effect" hypothesis in which individuals with PTSD perpetually smoke in such a way as to maximize nicotine delivery, possibly reducing the potentially reinforcing effects of increased smoke delivery in negative affect-inducing situations.

Adult↗

PubMed2005

Mecamylamine moderates cue-induced emotional responses in smokers.

The nicotinic antagonist, mecamylamine, has been shown to reduce cue-elicited cocaine craving and to aid in smoking cessation. In a within-subjects design, 16 dependent smokers received mecamylamine (10 mg) or placebo capsules on two different days. Subjects imagined smoking urge and non-urge scenarios after smoking their usual brand vs. denicotinized cigarettes. Smoking usual-brand cigarettes produced greater positive effects and mecamylamine blocked heart rate (HR) boost and cigarette sensory impact. Mecamylamine also resulted in greater craving and less calmness, regardless of cigarette smoked. Urge script imagination in the mecamylamine+denicotinized condition resulted in calmness similar to usual-brand conditions and higher than the placebo+denicotinized condition. A similar trend was observed for negative affect. These results suggest that mecamylamine can moderate smoking cue-induced emotional responses in smokers.

Adult↗

PubMed2005

Abstinence-induced changes in self-report craving correlate with event-related FMRI responses to smoking cues.

Drug cues have been shown to activate brain regions involved in attention, motivation, and reward in addicted users. However, as studies have typically measured responses in only one state (ie drug abstinence), it is unclear whether observed activations represent amplification by abstinence or stable responses. Thus, the present study was designed to evaluate the stability of event-related responses to visual drug cues in dependent smokers (n=13) using event-related functional magnetic resonance imaging measures. Imaging was conducted following smoking as usual and following overnight abstinence, and self-reported craving measures were obtained before, during, and after scanning. Analysis of hemodynamic response (HDR) amplitudes in each of 13 regions of interest revealed larger responses to smoking compared to control cues in ventral anterior cingulate gyrus (vACG) and superior frontal gyrus. Responses to smoking cues in these and all other regions revealed no effects of abstinence/satiety, thus supporting the notion that cue-elicited brain responses are relatively stable. However, while the abstinence manipulation did not alter group-level responses to smoking cues, at the individual level, abstinence-induced changes in craving (abstinence minus satiety) were positively correlated with changes in HDR amplitude to smoking cues in frontal regions including left inferior frontal gyrus, left vACG, and bilateral middle frontal gyrus. These results suggest that brain responses to smoking cues, while relatively stable at the group level following short-term abstinence, may be modulated by individual differences in craving in response to abstinence-particularly in regions subserving attention and motivation.

Adult↗

PubMed2004

The effects of controlled deep breathing on smoking withdrawal symptoms in dependent smokers.

This study was designed to assess the effect of controlled deep breathing on smoking withdrawal symptoms. In two laboratory sessions, dependent smokers refrained from smoking for 4 h. During a deep breathing session, participants were instructed to take a series of deep breaths every 30 min. During a control session, participants sat quietly. Controlled deep breathing significantly reduced smoking withdrawal symptoms, including craving for cigarettes and negative affect (tense, irritable), while resulting in the maintenance of baseline arousal (wide awake, able to concentrate) levels. Furthermore, a history of heavy smoking was associated with greater increases in arousal during the deep breathing session. The results of this preliminary study suggest that controlled deep breathing may be useful for relieving symptoms of smoking withdrawal.

Adult↗

PubMed2004

Cigarette smoking, ambulatory cardiovascular monitoring, and mood in Vietnam veterans with and without chronic posttraumatic stress disorder.

This study investigated the association among cigarette smoking, posttraumatic stress disorder (PTSD), and ambulatory cardiovascular and mood monitoring in 117 male Vietnam combat veterans (61 with PTSD and 56 without PTSD). Positive smoking status was associated with higher systolic blood pressure (SBP) and heart rate (HR), as well as greater diastolic blood pressure (DBP) variability. Compared to individuals without PTSD, PTSD patients had higher HR, anger/hostility ratings, and depression/anxiety ratings. Significant diagnosis by smoking status interactions were found indicating that compared to nonsmokers with PTSD, smokers with PTSD had higher DBP, mean arterial pressure (MAP), and positive affect. Ad lib cigarette smoking during the previous 30 min did not have a significant effect on mood or cardiovascular parameters, except in non-PTSD smokers who reported lower depression/anxiety ratings after smoking. Findings suggest that the effect of smoking on cardiovascular parameters may be amplified in smokers in PTSD. Findings suggest that the interrelationships among cardiovascular parameters, cigarette smoking, and PTSD deserve more research attention.

Adult↗

PubMed2004

Effects of nicotine on brain responses to emotional pictures.

Given that nicotine reduces negative affect, one would expect nicotine to have different effects on brain responses to emotionally negative stimuli than it does on responses to emotionally neutral or positive stimuli. However, no studies have assessed this possibility. The present study assessed the effects of nicotine patch versus placebo patch on brain event-related potential (ERP) responses to emotion-inducing negative, positive, and neutral color pictures in 16 smokers in a double-blind, counterbalanced, within-subjects design. The study included four experimental sessions. After overnight smoking deprivation (12 hr or more), active nicotine patches were applied to participants during one of the first two sessions and during one of the last two sessions. Placebo patches were applied during the other two sessions. Nicotine reduced frontal ERP processing voltage negativity (from 144-488 ms poststimulus onset) evoked by viewing emotionally negative pictures to a greater extent than it did when emotionally neutral pictures were viewed, whereas it had no effect on processing negativity evoked by positive pictures. Nicotine also enhanced P390 amplitudes evoked by emotionally negative pictures more than it did when emotionally neutral and positive pictures were viewed. Across picture types, nicotine (relative to placebo) reduced N300 amplitude (more at anterior and dorsal sites) and increased P390 amplitude. Overall, nicotine influenced ERPs to emotionally neutral and positive pictures less than it did to negative pictures.

Adult↗

PubMed2004

Human functional neuroimaging in nicotine and tobacco research: basics, background, and beyond.

Modern functional neuroimaging techniques allow nicotine and tobacco researchers to investigate the neurobiological basis of addiction in humans. We introduce the methods and measures of the following neuroimaging techniques: Electroencephalography and event-related cortical potentials, positron emission tomography, and functional magnetic resonance imaging. We outline strengths and limitations across modalities and describe new and emerging technologies. We provide summaries of recent neuroimaging findings in the field of nicotine and tobacco research for neurochemistry, smoking and nicotine administration, craving and cue-reactivity, cognitive and affective information processing, and tobacco withdrawal. We address limitations of studies to date and identify opportunities for future research.

Affect↗

PubMed2003

Effects of transdermal nicotine on lateralized identification and memory interference.

It has been proposed that nicotine may enhance performance on tasks requiring primarily left hemisphere (LH) resources while impairing right hemisphere (RH)-based performance. However, this hypothesis has not been directly tested using a lateralized cognitive task. The effects of transdermal nicotine administration on lateralized consonant identification and memory interference were examined in dependent smokers and never-smokers. In a double-blind placebo-controlled design, smokers (n = 24) and never-smokers (n = 24) were assigned to receive a nicotine or placebo patch. Subjects completed a lateralized letter identification task that required them to identify strings of three consonants presented in the left or right visual field while keeping a word in memory. A distinct right-visual-field (RVF) advantage was observed for consonant identification, but this effect was unaltered by nicotine or smoking status. However, nicotine decreased word memory errors on trials where consonants were presented in the RVF and increased errors on LVF trials. Nicotine may enhance LH-based cognitive performance by increasing LH cognitive resources or by reducing the influence of RVF distracting stimuli. These findings are consistent with a model of the lateralized effects of nicotine on cognitive performance.

Administration, Cutaneous↗

PubMed2002

Mood disturbance fails to resolve across 31 days of cigarette abstinence in women.

Smoking abstinence responses were characterized in 96 female smokers. Participants completed subjective state measures twice per week for 5 weeks and were then randomly assigned to a group required to abstain for 31 days or a control group that continued to smoke. Financial incentives for biochemically verified abstinence resulted in an 81% completion rate. Abstinence-related increases in depression, tension, anger, irritability, and appetite showed little tendency to return to prequit levels and remained significantly elevated above smoke-group levels. In contrast to psychological components of anxiety, physical components decreased to smoke group levels by the 2nd week of abstinence. Trait depression and neuroticism predicted larger increased abstinence-associated negative affect. The Big Five personality dimensions predicted variance not associated with depressive traits.

Adult↗