Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

Factors influencing the temporal relationship between alcohol consumption and experiences with aggression among college women.

The authors assessed temporal relationships among alcohol use, aggression, and mood using daily data from 179 college women. Participants called an interactive voice response system over an 8-week period. The odds of experiencing verbal, sexual, and physical aggression (odd ratios = 2.25, 19.44, and 11.84, respectively) were significantly higher on heavy drinking days (M = 7.46 drinks) compared to nondrinking days. Both a history of victimization and greater psychological symptom severity influenced the odds of involvement in verbal aggression. The odds of alcohol consumption were 3 times higher during the 24 hr following verbal aggression compared with days in which verbal aggression did not occur. On the day immediately following involvement in either verbal or physical aggression, positive mood decreased and negative mood increased. During the week (2-7 days) following sexual aggression, women's positive mood was decreased. These findings reinforce the need for interventions aimed at reducing heavy episodic drinking on college campuses.     

A Psychometric Evaluation of the Approach and Avoidance of Alcohol Questionnaire (AAAQ) in Alcohol Dependent Outpatients

The Approach and Avoidance of Alcohol Questionnaire (AAAQ; McEvoy et al. in Addiction 99:482–497, 2004) was administered to a clinical sample of 138 alcohol dependent men and women. An exploratory factor analysis was used to determine the AAAQ factor structure and a confirmatory analysis run on a second administration of the AAAQ. Convergent validity was examined by conducting an alcohol cue reactivity test and by administering the Timeline Follow-Back (TLFB), a retrospective calendar method for assessing alcohol consumption, and several measures of alcohol-related problems. The factor analysis supported a two-factor solution representing approach and avoidance dimensions. Regressions predicting measures of alcohol cue reactivity, alcohol consumption, and other alcohol-related constructs with the AAAQ provide support for its convergent validity. The results suggest that alcohol craving may be viewed as a multi-dimensional construct that includes both approach and avoidance inclinations which may vary depending on the population under examination.

Hypothalamo-Pituitary-Adrenocortical Regulation Following Lesions of the Central Nucleus of the Amygdala

Previous reports indicate that the central nucleus of the amygdala (CeA) stimulates adrenocorticotropin and corticosterone secretion, suggesting a role for this region in central hypothalamo-pituitary-adrenocortical (HPA) stress regulation. To evaluate this hypothesis, this study assessed the impact of CeA lesion on the response of hypophysiotrophic paraventricular nucleus (PVN) neurons to acute restraint and chronic unpredictable stress exposure. In contrast to previous reports, CeA lesions did not affect corticosterone or ACTH secretion induced by acute stress. Acute restraint increased PVN corticotropin releasing hormone (CRH) mRNA expression, increased the number of parvocellular PVN neurons expressing the co-secretagogue arginine vasopressin (AVP), and induced cFOS mRNA expression in the parvocellular PVN. However, there was no additional effect of CeA lesion on any measure of PVN activation. Chronic unpredictable stress exposure induced long-term activation of the HPA axis, noted by thymic involution, adrenal hypertrophy and increased PVN CRH mRNA expression. Stress-induced changes in thymus and adrenal weights were not affected by CeA lesion. Further, CeA lesion rats did not differ from controls in post-stress CRH mRNA expression. However, basal CRH mRNA expression was increased in the PVN of CeA rats, suggesting that the CeA plays a role in long-term inhibition of the PVN. The results of these studies are not consistent with the hypothesis that the CeA is necessary for stress-induced pituitary-adrenocortical activation. Rather, this region may play a stressor-specific modulatory role in regulation of HPA function.     

Factors affecting agreement between severely mentally ill alcohol abusers' and collaterals' reports of alcohol and other substance abuse.

This study examined subject-collateral reports of alcohol use among a sample of 167 dually diagnosed individuals seeking outpatient treatment at a community mental health clinic. All subjects met Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) criteria for a schizophrenia-spectrum or bipolar disorder and for alcohol abuse or dependence. Subjects were recruited within 2 weeks of treatment entry and completed measures of cognitive functioning, alcohol dependence severity, psychiatric symptoms, and quantity and frequency of substance use over the previous 60 days using the Timeline Follow-Back interview (L. C. Sobell & M. B. Sobell, 1996). They also provided a urine sample, which was screened for recent drug use. Collateral interviews were conducted by phone and included an assessment of the subject's alcohol and drug use over the same 60-day period. Collaterals also reported their confidence in the accuracy of their reports. Overall, the results indicated generally poor subject-collateral agreement. However, subject-collateral agreement appeared better for those individuals (n = 97) with negative urine drug screens. The most consistent predictor of subject-collateral discrepancy scores was subjects' recent drug use. Recommendations for enhancing the validity of self-reports of substance use in a severely mentally ill population are discussed.     

Exposure to negative emotional cues and alcohol cue reactivity with alcoholics: a preliminary investigation

Fifty-one male and female inpatient alcoholics received cue exposure treatment involving in vivo exposure to alcohol cues and imaginal exposure to individualized high-risk drinking situations involving negative emotional cues. At post-test, self-report measures of urge to drink alcohol and negative emotional states were obtained during an alcohol cue reactivity assessment. Contrary to our hypothesis, greater exposure to negative emotional cues during treatment was associated with greater urge and negative emotional responses at post-test. In addition, greater duration of exposure to negative emotional cues predicted greater attention to alcohol-related stimuli and thoughts about drinking during the post-test. Implications for future research in this area include extending the duration of exposure to negative emotional cues in order to establish the optimal exposure durations within which a majority of individuals achieve clinically significant reductions in their urge to drink alcohol.     

A beverage-specific measure of expectancies for malt liquor: development and initial testing

Malt liquor (ML) is a unique, high alcohol content beverage marketed to encourage heavy drinking. We developed the Malt Liquor Expectancy Questionnaire (MLEQ), a beverage-specific measure of alcohol expectancies, and examined its association with typical weekly ML use, typical weekly alcohol use, and alcohol problems. Forty positive and 40 negative expectancy items were administered to a sample of 639 young adults who regularly consumed ML. Exploratory and confirmatory factor analyses led to the development of the 30-item MLEQ. The MLEQ consists of two positive (i.e., Social Facilitation and Enjoyment, Enhanced Sexuality) and two negative factors (i.e., Aggression and Negative Consequences; Impairment and Physical Symptoms) that possess good internal consistency, test-retest reliability, and convergent validity. The psychometrically sound MLEQ contributes to the limited research on beverage-specific expectancies and heavy drinking.