Biomedical subjects

S H Stewart

Publications and source records attributed to S H Stewart.

At least 19 recordsLinked to original sources

PubMed2002

Cognitive and sedative effects of benzodiazepine use.

This paper reviews the effects of benzodiazepines (BZs) on the performance of tasks measuring human cognitive abilities. The paper reviews the most common cognitive side effects of BZs: increased sedation, decreased attention, and anterograde amnesia. In particular, this paper focuses on recent findings regarding time course-related effects on BZ-induced deficits in explicit and implicit human memory performance. Specifically, we reviewed recent research indicating that both explicit memory and priming are impaired by BZs if the encoding task takes place near the time of the theoretical peak plasma concentrations of the drug. Although BZs also appear to increase objective and subjective sedation, as well as to impair attentional processing, these other cognitive impairments do not appear to fully account for the widespread memory deficits caused by BZ administration. The theoretical and clinical implications of benzodiazepine-induced memory impairments are discussed.

Animals↗

PubMed2002

Benzodiazepine side-effects: from the bench to the clinic.

This article introduces a special issue of Current Pharmaceutical Design focusing on the various side effects of benzodiazepine medications. We argue that an increased awareness of the risk of dependence, withdrawal symptoms upon discontinuation, and cognitive side effects of the benzodiazepines has likely contributed to the decline in their prescription rate over the last two decades, as has increased availability of alternative pharmacologic and non-pharmacologic treatments for anxiety and insomnia. The present special issue consists of series of five papers covering current issues in the area of benzodiazepine side effects. These reviews cover a wide range of topics pertaining to adverse, unintended consequences of this class of pharmacologic agents including their potential for tolerance and withdrawal, their profile of associated cognitive impairments, as well as current understanding of means for minimizing these unintended effects. The reviews also cover a variety of methodologies and disciplines from laboratory-based research findings with animals, to laboratory-based studies with healthy human volunteers, to findings obtained in the clinic with anxious patients. All reviews are timely contributions, covering highly relevant topics for consideration of benzodiazepine side effects at present. The papers presented herein should serve to stimulate future research that may ultimately help improve the quality of life of those patients living with debilitating anxiety-related conditions.

Animals↗

PubMed2002

As-needed use of benzodiazepines in managing clinical anxiety: incidence and implications.

Benzodiazepines (BZs) have been widely investigated in terms of clinical efficacy, factors underlying dependence, associated cognitive impairments, and interactions with psychotherapy for anxiety control. However, few studies have systematically considered manner of BZ administration in relation to these variables. Studies of chronic BZ users indicate that as-needed or p.r.n. use is a very common practice, increases with chronicity of BZ use, and is preferred compared to regularly scheduled BZ administration. Moreover, a recent study of physician prescription practices indicated that p.r.n. BZ use is a commonly recommended BZ use regimen for anxiety disorder management. Physician advocates of p.r.n. BZ prescriptions for anxiety disorders cite enhanced patient control over symptoms, facilitation of exposure to fear-provoking situations, and reduced frequency of use as rationales supporting this practice. Available data however, do not consistently support these hypothesized advantages of p.r.n. BZ use. And in general, findings from different investigations relevant to this question suggest that p.r.n. BZ administration may be associated with increased patient preference for BZs over placebo, continued use, and greater impairment on cognitive factors associated with positive long-term anxiety management. Ironically, p.r.n. BZ administration may also be associated with reduced anxiolytic efficacy over time. These suggestive findings argue for greater systematic investigation of manner of BZ administration as an important medication use parameter. Such investigations may also yield practical guidelines for navigating BZ discontinuation and promoting more successful long-term management of anxiety.

Anti-Anxiety Agents↗

PubMed2002

Alcohol and inflammation: a possible mechanism for protection against ischemic heart disease.

AIM: Moderate alcohol consumption has been associated with a decreased risk for ischemic heart disease. Increases in high-density lipoprotein-cholesterol may explain approximately 50% of this apparent benefit. Another potential mechanism may involve the effects of alcohol on systemic inflammation. Accordingly, the purpose of this article is to provide a narrative review of the literature concerning alcohol and inflammation. DATA SYNTHESIS: Relevant articles were identified by searching MEDLINE from 1966 to 2001. Search terms included alcohol or ethanol combined with inflammation, interleukin-1, interleukin-6, or tumor necrosis factor alpha. Important references from these articles were also identified and reviewed. CONCLUSIONS: Considerable evidence exists from animal and human studies for potentially anti-inflammatory effects of alcohol consumption. Further research is needed to determine the effects of various patterns and levels of alcohol consumption on systemic markers of inflammation in humans.

Alcohol Drinking↗

PubMed2001

Assessment of anxiety sensitivity in young American Indians and Alaska Natives.

In the present study, the Anxiety Sensitivity Index [ASI; Behav. Res. Ther. 24 (1986) 1] was administered to 282 American Indian and Alaska Native college students in a preliminary effort to: (a) evaluate the factor structure and internal consistency of the ASI in a sample of Native Americans; (b) examine whether this group would report greater levels of anxiety sensitivity and gender and age-matched college students from the majority (Caucasian) culture lesser such levels; and (c) explore whether gender differences in anxiety sensitivity dimensions varied by cultural group (Native American vs. Caucasian). Consistent with existing research, results of this investigation indicated that, among Native peoples, the ASI and its subscales had high levels of internal consistency, and a factor structure consisting of three lower-order factors (i.e. Physical, Psychological, and Social Concerns) that all loaded on a single higher-order (global Anxiety Sensitivity) factor. We also found that these Native American college students reported significantly greater overall ASI scores as well as greater levels of Psychological and Social Concerns relative to counterparts from the majority (Caucasian) culture. There were no significant differences detected for ASI physical threat concerns. In regard to gender, we found significant differences between males and females in terms of total and Physical Threat ASI scores, with females reporting greater levels, and males lesser levels, of overall anxiety sensitivity and greater fear of physical sensations; no significant differences emerged between genders for the ASI Psychological and Social Concerns dimensions. These gender differences did not vary by cultural group, indicating they were evident among Caucasian and Native Americans alike. We discuss the results of this investigation in relation to the assessment of anxiety sensitivity in American Indians and Alaska Natives, and offer directions for future research with the ASI in Native peoples.

Adolescent↗

PubMed2001

Causal modeling of relations among learning history, anxiety sensitivity, and panic attacks.

We used structural equation modeling (SEM) to test the hypothesis that childhood instrumental and vicarious learning experiences influence frequency of panic attacks in young adulthood both directly, and indirectly through their effects on anxiety sensitivity (AS). A total of 478 university students participated in a retrospective assessment of their childhood learning experiences for arousal-reactive sensations (e.g., nausea, racing heart, shortness of breath, dizziness) and arousal-non-reactive sensations (i.e., colds, aches and pains, and rashes). SEM revealed that learning history for arousal-reactive somatic symptoms directly influenced both AS levels and panic frequency; AS directly influenced panic frequency; and learning history for arousal-non-reactive symptoms directly influenced AS but did not directly influence panic frequency. These results are consistent with the findings of previous retrospective studies on the learning history origins of AS and panic attacks, and provide the first empirical evidence of a partial mediation effect of AS in explaining the relation between childhood learning experiences and panic attacks in young adulthood. Implications for understanding the etiology of panic disorder are discussed.

Adult↗

PubMed2001

Manipulations of the features of standard video lottery terminal (VLT) games: effects in pathological and non-pathological gamblers.

The present study was conducted to identify game parameters that would reduce the risk of abuse of video lottery terminals (VLTs) by pathological gamblers, while exerting minimal effects on the behavior of non-pathological gamblers. Three manipulations of standard VLT game features were explored. Participants were exposed to: a counter which displayed a running total of money spent; a VLT spinning reels game where participants could no longer "stop" the reels by touching the screen; and sensory feature manipulations. In control conditions, participants were exposed to standard settings for either a spinning reels or a video poker game. Dependent variables were self-ratings of reactions to each set of parameters. A set of 2(3) x 2 x 2 (game manipulation [experimental condition(s) vs. control condition] x game [spinning reels vs. video poker] x gambler status [pathological vs. non-pathological]) repeated measures ANOVAs were conducted on all dependent variables. The findings suggest that the sensory manipulations (i.e., fast speed/sound or slow speed/no sound manipulations) produced the most robust reaction differences. Before advocating harm reduction policies such as lowering sensory features of VLT games to reduce potential harm to pathological gamblers, it is important to replicate findings in a more naturalistic setting, such as a real bar.

Adult↗

PubMed2000

Illness Attitudes Scale dimensions and their associations with anxiety-related constructs in a nonclinical sample.

The Illness Attitudes Scale (IAS) is a self-rated measure that consists of nine subscales designed to assess fears, attitudes and beliefs associated with hypochondriacal concerns and abnormal illness behavior [Kellner, R. (1986). Somatization and hypochondriasis. New York: Praeger; Kellner, R. (1987). Abridged manual of the Illness Attitudes Scale. Department of Psychiatry, School of Medicine, University of New Mexico]. The purposes of the present study were to explore the hierarchical factor structure of the IAS in a nonclinical sample of young adult volunteers and to examine the relations of each illness attitudes dimension to a set of anxiety-related measures. One-hundred and ninety-seven undergraduate university students (156 F, 41 M; mean age = 21.9 years) completed the IAS as well as measures of anxiety sensitivity, trait anxiety and panic attack history. The results of principal components analyses with oblique (Oblimin) rotation suggested that the IAS is best conceptualized as a four-factor measure at the lower order level (with lower-order dimensions tapping illness-related Fears, Behavior, Beliefs and Effects, respectively), and a unifactorial measure at the higher-order level (i.e. higher-order dimension tapping General Hypochondriacal Concerns). The factor structure overlapped to some degree with the scoring of the IAS proposed by Kellner (1986, 1987), as well as with the factor structures identified in previously-tested clinical and nonclinical samples [Ferguson, E. & Daniel, E. (1995). The Illness Attitudes Scale (IAS): a psychometric evaluation on a nonclinical population. Personality and Individual Differences, 18, 463-469; Hadjistavropoulos, H. D. & Asmundson, G. J. G. (1998). Factor analytic investigation of the Illness Attitudes Scale in a chronic pain sample. Behaviour Research and Therapy, 36, 1185-1195; Hadjistavropoulos, H. D., Frombach, I. & Asmundson, G. J. G. (in press). Exploratory and confirmatory factor analytic investigations of the Illness Attitudes Scale in a nonclinical sample. Behaviour Research and Therapy; Speckens, A. E., Spinhoven, P., Sloekers, P. P. A., Bolk, J. H. & van Hemert, A. M. (1996). A validation study of the Whitley Index, the Illness Attitude Scales and the Somatosensory Amplification Scale in general medical and general practice patients. Journal of Psychosomatic Research, 40, 95-104]. The Fears, Beliefs and Effects lower-order factors and the General Hypochondriacal Concerns higher-order factor, were shown to be strongly associated with anxiety sensitivity, even after accounting for trait anxiety and panic history. Implications for understanding the high degree of comorbidity between the diagnoses of panic disorder and hypochondriasis, as well as future research directions for exploring the utility of various IAS dimensions in predicting responses to lab-based bodily symptom-induction procedures, are discussed.

Adult↗

PubMed2000

Does the social concerns component of the anxiety sensitivity index belong to the domain of anxiety sensitivity or the domain of negative evaluation sensitivity?

The present study utilized an exploratory factor-analytic approach (i.e. principal-components analysis; PCA) to investigate whether the Social Concerns component of the Anxiety Sensitivity Index (ASI [Peterson, R. A., & Reiss, S. (1992). Anxiety Sensitivity Index manual (2nd ed.). Worthington, OH: International Diagnostic Systems.]) is best conceptualized as belonging to the domain of anxiety sensitivity (AS) and/or the domain of negative evaluation sensitivity (NES). A sample of university students (N = 216) was administered measures of both NES (i.e. Brief Fear of Negative Evaluation scale; Leary, 1983) and AS (i.e. ASI). Participants' responses to the items comprising these measures were subjected to a PCA with oblique rotation. Factors representing the NES construct and the three lower-order AS constructs (i.e. AS Physical, Psychological and Social Concerns) were obtained. Subscales derived from these four factors were positively and significantly correlated with one another and loaded on a single higher-order factor labeled Threat Sensitivity. Thus, the present findings suggest that the AS Social Concerns factor is distinct from NES and the other lower-order components of AS. However, correlational analyses and higher-order PCA indicated that the AS Social Concerns factor taps a blend of AS and NES as well as something unique and distinct from both global AS and NES.

Adolescent↗

PubMed2000

Anxiety sensitivity mediates the relationships between childhood learning experiences and elevated hypochondriacal concerns in young adulthood.

OBJECTIVE: the present study investigated childhood learning experiences potentially associated with the development of elevated hypochondriacal concerns in a non-clinical young adult sample, and examined the possible mediating roles of anxiety sensitivity (i.e., fear of anxiety-related symptoms) and trait anxiety (i.e., frequency of anxiety symptoms) in explaining these relationships. METHOD: 197 university students participated in a retrospective assessment of their childhood instrumental (i.e., parental reinforcement) and vicarious (i.e., parental modeling) learning experiences with respect to arousal-reactive (e.g., dizziness) and arousal-non-reactive (e.g., lumps) bodily symptoms, respectively. Childhood learning experiences were assessed using a revised version of the Learning History Questionnaire (LHQ), anxiety sensitivity levels with the Anxiety Sensitivity Index (ASI), trait anxiety levels with the State-Trait Anxiety Inventory-Trait (STAI-T) scale, and degree of hypochondriacal concerns with the Illness Attitudes Scale (IAS)-Total score. RESULTS: consistent with earlier findings [Watt MC, Stewart SH, Cox BJ. A retrospective study of the learning history origins of anxiety sensitivity. Behav Res Ther 1998; 36: 505-525.], elevated anxiety sensitivity levels were associated with increased instrumental and vicarious learning experiences related to both arousal-reactive and arousal-non-reactive bodily symptoms. Similarly, individuals with elevated hypochondriacal concerns also reported both more instrumental and vicarious learning experiences around bodily symptoms than did students with lower levels of such concerns. However, contrary to the hypothesis, the childhood learning experiences related to hypochondriacal concerns were not specific to arousal-non-reactive symptoms, but instead involved parental reinforcement and modeling of bodily symptoms in general (arousal-reactive and -non-reactive symptoms alike). Anxiety sensitivity, but not trait anxiety, partially mediated the relationships between childhood learning experiences and elevated hypochondriacal concerns in young adulthood. CONCLUSIONS: elevated anxiety sensitivity appears to be a risk factor for the development of hypochondriasis when learning experiences have involved both arousal-reactive and arousal-non-reactive bodily symptoms.

Adult↗

PubMed2000

Psychometric evaluation of the short form inventory of drinking situations (IDS-42) in a community-recruited sample of substance-abusing women.

PURPOSE: We investigated the psychometric properties (factor structure, internal consistency reliability, concurrent validity) of the Short Form Inventory of Drinking Situations (IDS-42) in women substance abusers. METHODS: A sample of 297 substance-abusing women was recruited from the community. The women completed the IDS-42 and the three-factor Drinking Motives Questionnaire (DMQ). RESULTS: Confirmatory factor analyses of IDS-42 items suggested a hierarchical structure for the scale. Eight factors (corresponding to Marlatt and Gordon's eight heavy drinking situations) provided the best model fit at the lower-order level, and three factors (i.e., Negatively Reinforcing vs. Positively Reinforcing vs. Temptation Situations) provided the best model fit at the higher-order level. Lower- and higher-order IDS-42 subscales were shown to possess adequate-to-high levels of internal consistency. The eight lower-order IDS-42 factors demonstrated excellent concurrent validity with conceptually similar DMQ subscale scores. Across the entire sample of female substance abusers, a higher frequency of heavy drinking was reported in Positively Reinforcing Situations and Unpleasant Emotions Situations, as compared to other heavy drinking situations. IMPLICATIONS: Results support the IDS-42's good psychometric properties and demonstrate its utility as a tool in identifying situation-specific antecedents to heavy drinking among women substance abusers.

Adult↗

PubMed2000

Relations between dietary restraint and patterns of alcohol use in young adult women.

The present study examined relations between dietary restraint and self-reported patterns of alcohol use, including separate assessment of quantity and frequency of alcohol consumption. One hundred seventy-six female university undergraduates completed the Restraint Scale (RS) and measures of their usual quantity and frequency of alcohol consumption over the past year. Quantity and frequency self-reports were scored separately and were also used to calculate 3 additional drinking variables: a composite weekly alcohol consumption score (drinks per week), a binge drinking categorical variable (where participants were classified as either binge drinkers or non-binge drinkers), and a yearly excessive drinking score (number of times in the past year that each participant consumed at least 4 alcoholic beverages per drinking occasion). RS scores were significantly positively correlated with scores on 4 of the 5 drinking behavior measures (i.e., quantity, drinks per week, binge drinking, and yearly excessive drinking, but not frequency). Thus, chronic dieting appears to be related to a relatively heavy drinking pattern that can be characterized as potentially risky, due to its established associations with adverse health and social consequences.

Adult↗

PubMed2000

Efficacy of brief coping skills interventions that match different personality profiles of female substance abusers.

Female substance abusers recruited from the community were randomly assigned to receive 1 of 3 brief interventions that differentially targeted their personality and reasons for drug use. The 90-min interventions were: (a) a motivation-matched intervention involving personality-specific motivational and coping skills training, (b) a motivational control intervention involving a motivational film and a supportive discussion with a therapist, and (c) a motivation-mismatched intervention targeting a theoretically different personality profile. Assessment 6 months later (N = 198) indicated that only the matched intervention proved to be more effective than the motivational control intervention in reducing frequency and severity of problematic alcohol and drug use and preventing use of multiple medical services. These findings indicate promise for a client-treatment matching strategy that focuses on personality-specific motives for substance abuse.

Adaptation, Psychological↗

PubMed2000

Validation of a system of classifying female substance abusers on the basis of personality and motivational risk factors for substance abuse.

This study explored the validity of classifying a community-recruited sample of substance-abusing women (N = 293) according to 4 personality risk factors for substance abuse (anxiety sensitivity, introversion-hopelessness, sensation seeking, and impulsivity). Cluster analyses reliably identified 5 subtypes of women who demonstrated differential lifetime risk for various addictive and nonaddictive disorders. An anxiety-sensitive subtype demonstrated greater lifetime risk for anxiolytic dependence, somatization disorder, and simple phobia, whereas an introverted-hopeless subtype evidenced a greater lifetime risk for opioid dependence, social phobia, and panic and depressive disorders. Sensation seeking was associated with exclusive alcohol dependence, and impulsivity was associated with higher rates of antisocial personality disorder and cocaine and alcohol dependence. Finally, a low personality risk subtype demonstrated lower lifetime rates of substance dependence and psychopathology.

Adult↗

PubMed2000

Effects of alcohol on the response to hyperventilation of participants high and low in anxiety sensitivity.

BACKGROUND: Previous research suggests that high levels of anxiety sensitivity (AS; fear of anxiety symptoms) may constitute a risk factor for alcohol abuse. The present study evaluated the hypothesis that high AS levels may increase risk for alcohol abuse by promoting a heightened sober reactivity to theoretically relevant stressors and heightened sensitivity to alcohol's emotional reactivity dampening effects, which would negatively reinforce drinking in this population. METHODS: One hundred and two undergraduate participants (51 high AS, 51 low AS) with no history of panic disorder were assigned to either a placebo, low-dose alcohol, or high-dose alcohol beverage condition (17 high AS, 17 low AS per beverage condition). After beverage consumption and absorption, participants underwent a 3 min voluntary hyperventilation challenge. RESULTS AND CONCLUSIONS: High-AS/placebo participants displayed greater affective and cognitive reactivity to the challenge than low-AS/placebo participants, which indicated increased fear and negative thoughts (e.g., "losing control") during hyperventilation among sober high AS individuals. Dose-dependent alcohol dampening of affective and cognitive reactivity to hyperventilation was observed only among high-AS participants, which suggested that high-AS individuals may be particularly sensitive to alcohol-induced reductions in their degree of fear and negative thinking in response to the experience of physical arousal sensations. In contrast, dose-dependent alcohol dampening of self-reported somatic reactivity was observed among both high- and low-AS participants. We discuss implications of these results for understanding risk for alcohol abuse in high-AS individuals, as well as directions for future research.

Adult↗

PubMed1999

Relations between anxiety sensitivity and dimensions of alexithymia in a young adult sample.

This study was conducted to assess the relations between anxiety sensitivity (AS) and dimensions of alexithymia in a nonclinical sample. We also sought to determine whether these relations persist after controlling for trait anxiety levels and panic attack history, and after controlling for item redundancy between the Anxiety Sensitivity Index (ASI) and the 20-item Toronto Alexithymia Scale (TAS-20). A sample of 238 undergraduate students completed the ASI, the TAS-20, and measures of trait anxiety and panic. A group of high AS participants (n=36) was found to have a significantly higher TAS-20 total score than a group of low AS participants (n=41), both before and after conceptually redundant TAS-20 items were removed. ASI scores were found to be significantly positively correlated with scores on the two TAS-20 subscales suspected of sharing a functional relation with AS (i.e., difficulty identifying emotions; difficulty describing emotions), whereas ASI scores were not significantly correlated with scores on the TAS-20 subscale believed to be functionally unrelated to AS (i.e., external-oriented thinking). This pattern of correlations between ASI scores and alexithymia dimensions persisted following the removal of conceptually redundant TAS-20 items, suggesting that the relation between AS and alexithymia is not merely an artifact of item redundancy. ASI scores remained significantly correlated with scores on the TAS-20's difficulty identifying emotions subscale, and marginally correlated with scores on the TAS-20's difficulty describing emotions subscale, after accounting for the influences of trait anxiety and panic history. The results also revealed that individuals who both experience frequent anxiety and who greatly fear their anxiety symptoms report the greatest difficulties identifying and describing emotional states. Implications for understanding the alexithymia construct, as well as potential clinical implications of the findings, are discussed.

Adult↗

PubMed1998

A further examination of the time-dependent effects of oxazepam and lorazepam on implicit and explicit memory.

Until recently, research indicated that all benzodiazepines impair explicit memory, while only lorazepam impairs priming. Stewart and associates provided preliminary data which indicated that both oxazepam and lorazepam may impair implicit memory, but in a time-dependent fashion. The present study was designed to replicate Stewart et al.'s findings after overcoming several limitations of the original study. Thirty subjects were administered an acute dose of lorazepam (2 mg), oxazepam (30 mg) or a placebo and were tested with an implicit (word-stem completion) test and an explicit (cued recall) test. However, subjects were only tested at 170 min post-drug (close to oxazepam's theoretical peak concentration) to rule out the possible "explicit memory contamination" explanation of the Stewart et al. implicit memory findings. Consistent with previous research, both drugs impaired explicit memory relative to placebo. Also, both lorazepam and oxazepam impaired priming performance, supporting the "time-dependence" interpretation of the Stewart et al. findings. The results also indicate that episodic memory is impaired by both benzodiazepines in a time-dependent fashion even when the research methodology used involves everyday memory demands.

Adult↗

PubMed1998

A retrospective study of the learning history origins of anxiety sensitivity.

Anxiety sensitivity (AS; the fear of anxiety-related sensations) has been proposed as a risk factor for the development of panic disorder. The present study involved a conceptual replication of Ehlers' (1993, Behaviour Research and Therapy, 31, 269-278) study on childhood learning experiences and panic attacks, but also extended her work by investigating the relationship between early learning experiences and the development of AS, in a non-clinical sample. A sample of 551 university students participated in a retrospective assessment of their childhood and adolescent instrumental and vicarious learning experiences with respect to somatic symptoms (i.e. anxiety and cold symptoms, respectively) using an expanded version of Ehler's (1993) Learning History Questionnaire. AS levels were assessed using the Anxiety Sensitivity Index, and panic history was obtained using the Panic Attack Questionnaire, Revised. Contrary to hypotheses, the learning experiences of high AS individuals were not found to be specific to anxiety symptoms, but involved parental reinforcement of sick-role behavior related to somatic symptoms in general. High AS subjects reported both more anxiety and cold symptoms prior to age 18 than individuals with lower levels of AS. In addition, both cold and anxiety symptoms elicited more special attention and/or instructions from parents for high AS individuals to take special care of themselves. These findings are contrasted with the results for self-reported panickers who reported more learning experiences (modeling and parental reinforcement) specific to anxiety-related symptoms, than the non-panickers. The results suggest that higher-than-normal levels of AS may arise from learning to catastrophize about the occurrence of bodily symptoms in general, rather than anxiety-related symptoms in particular.

Adult↗