Can psychosocial work factors influence psychologists' positive mental health?

BACKGROUND: Working in healthcare can entail intense emotional demands that increases susceptibility to occupational risk factors. Psychosocial risk assessment can contribute to promoting awareness of the effects of work on positive mental health. AIMS: To explore and analyse the influence of psychosocial work factors on positive mental health among psychologists. METHODS: A cross-sectional study of 339 psychologists was conducted. Two instruments were used for data collection: the Mental Health Continuum-Short Form (MHC-SF) to assess well-being and the Health and Work Survey (INSAT) to assess psychosocial work factors. RESULTS: This study identified psychosocial work factors that affect psychologists' positive mental health, namely, emotional well-being was affected by 'Need help from colleagues' (ß = -1.091), 'Have no one I can trust' (ß = -1.253) and 'Complex work' (ß = 0.751); psychological well-being was affected by 'Intense work pace' (ß = 1.151), 'Not able to participate in decisions' (ß = -3.695) and 'Complex work' (ß = 1.520); and social well-being was affected by 'Always changing roles and tasks' (ß = -1.810) and 'Not able to participate in decisions' (ß = -2.470). CONCLUSIONS: Psychosocial work factors such as work organization, work relationships and emotional demands influence psychologists' positive mental health. Social support at the workplace and having challenging and autonomous work can promote mental health. It is important to develop better organizational practices to promote mental health and well-being among these professionals.

A review of olanzapine as an antiemetic in chemotherapy-induced nausea and vomiting and in palliative care patients.

Olanzapine is an atypical antipsychotic agent that blocks multiple neuronal receptors involved in the nausea and vomiting pathways. It has therefore been studied for the prevention and treatment of chemotherapy-induced emesis and in patients in palliative care presenting nausea and vomiting refractory to standard antiemetics. Some studies have shown that olanzapine was not inferior to aprepitant in the prophylaxis of highly and moderately emetogenic chemotherapy and that it increased the rate of complete response when added to a combination of a 5-HT3 antagonist, aprepitant and dexamethasone. These studies present so many shortcomings, however, that they do not permit us to draw any firm conclusions. Oral olanzapine showed superior antiemetic efficacy to metoclopramide as rescue treatment to control breakthrough emesis induced by chemotherapy. However, an oral formulation is not appropriate because in patients with vomiting or severe nausea the mere ingestion of an oral drug could induce emesis. Finally, in palliative care olanzapine could control or reduce the intensity of nausea and vomiting refractory to standard antiemetics.

Cross-validation of a new procedure for early screening of smoking cessation medications in humans.

Brief procedures for evaluating medication efficacy may reveal which candidate drugs warrant further testing in clinical trials and which do not. We previously carried out a study of smoking abstinence, involving the nicotine patch, and established the sensitivity of our procedure. In this study, we sought to cross-validate our earlier work by comparing short-term smoking abstinence due to varenicline (relative to placebo) in smokers with high intrinsic quit interest (n = 57) and those with low intrinsic quit interest (n = 67). All the subjects were randomly assigned to either abstinence reinforcement ($12/day) or no reinforcement. In a crossover design, all the subjects participated in two 3-week phases: ad libitum smoking (week 1), dose run-up of varenicline (1.0 mg b.i.d.) or placebo (week 2), and quit attempt on medication verified daily by carbon monoxide <5 ppm (week 3). As with the nicotine patch in the previous study, varenicline (relative to placebo) increased abstinence more effectively in those with high intrinsic quit interest than in those with low quit interest but did not affect abstinence due to reinforcement. These data confirm the feasibility of a brief, sensitive test of the efficacy of cessation medications in smokers with high quit interest.

Development of procedures for early screening of smoking cessation medications in humans.

Candidate medications for smoking cessation may be screened more efficiently if initial evaluations in humans combine the practical advantages of laboratory studies with the clinical validity of clinical trials, such as by increasing participants' "quit motivation" during brief testing. We manipulated "intrinsic" quit motivation by recruiting smokers who either did intend to quit soon ("treatment seekers," N = 47) or did not ("nonseekers," N = 93), and "extrinsic" quit motivation by providing or not providing reinforcement for abstinence ($12/day). All the subjects smoked as they would usually do during weeks 1 and 3, and tried to quit during weeks 2 and 4 using either a nicotine patch (21 mg) or a placebo patch, in accordance with the crossover design of the study. The nicotine patch increased abstinence in treatment seekers but not in nonseekers. Reinforcement had a main effect on abstinence but did not moderate the effects of the nicotine patch or treatment-seeking status. Intrinsic, but not extrinsic, quit motivation of participants may enhance the validity of brief tests of medication efficacy for smoking cessation.

Bacterial sepsis.

Bacterial sepsis remain a major cause of mortality and morbidity in the newborn. The severe outcome of neonatal sepsis, despite the advances in perinatal and neonatal care and use of potent antibiotics, is related to the neonatal reduced immune defenses and the complex interactions between the infecting microorganism and the host responses. An early diagnosis, based on the clinical picture, the isolation of microorganisms and the positivity of inflammatory indexed, is mandatory. A timely treatment should be aimed to the elimination of pathogens with antimicrobials. Intravenous immunoglobulin and hematopoietic growth factors may be considered to improve the disturbed immune homeostases.

The influence of alcohol pre-treatment on the discriminative stimulus, subjective, and relative reinforcing effects of nicotine.

Alcohol intake may acutely alter the discriminative stimulus and subjective effects of nicotine, perhaps explaining why alcohol increases tobacco smoking. In this study, cigarette smokers were initially trained to discriminate 20 microg/kg nicotine by nasal spray from placebo. Three sessions then followed, in which the generalization of nicotine discrimination was tested across a range of doses (0--20 microg/kg) following pre-treatment with 0, 0.4, and 0.8 g/kg alcohol p.o. Intermittent 'topping' doses of alcohol maintained a steady breath alcohol level (BAL) throughout testing. Generalization testing involved both two- and three-choice ('novel' option) procedures. A visual discrimination task was also conducted to determine the specificity of effects of alcohol. Subjective and cardiovascular measures were obtained concurrent with discrimination responding. The relative reinforcing effects of nicotine were assessed after the end of generalization testing using a choice procedure. Alcohol pre-treatment had no significant effects on nicotine discrimination or self-administration behavior. Alcohol and nicotine each influenced selected subjective responses and heart rate, but virtually no interactions between the drugs were observed. Within the limitations of this study, these results do not support the notion that alcohol acutely alters nicotine's discriminative stimulus, subjective, or relative reinforcing effects at these low nicotine doses. Acute effects of alcohol on smoking behavior may be due to alterations in other effects of nicotine intake or in non-nicotine effects of tobacco smoking.

Quitting cigarette smoking produces minimal loss of chronic tolerance to nicotine.

RATIONALE: Long-term exposure to nicotine is associated with chronic tolerance to its acute effects, adaptation that may lead to tobacco dependence. The time course for loss of this tolerance after cessation of exposure is not known in humans but could relate to risk of smoking relapse. OBJECTIVES: We examined changes in responses to nicotine as a function of days, weeks, or years of smoking cessation in formerly dependent smokers to determine at what point sensitivity to nicotine is reinstated (i.e., loss of tolerance). METHODS: Acute subjective, cardiovascular, performance, and reinforcing (self-administration) effects of nicotine nasal spray (0-20 microg/kg) were assessed prospectively in men and women smokers before and then day-by-day (study 1) or 3 weeks (study 2) after stopping smoking. A smoking resumption period (study 1) and a group of non-quitting smokers (study 2) were included to control for the passage of time. These effects were also compared cross-sectionally between those who had quit for 1-4 years and those who had for 6-19 years in a separate sample of long-time ex-smokers to determine whether lengthier abstinence causes greater loss of tolerance (study 3). RESULTS: No clear loss of tolerance was observed on any measure in studies 1 or 2, suggesting that chronic tolerance is fully maintained for at least weeks after quitting smoking. Sensitivity to nicotine's effects was also not different as a function of years quit in study 3. CONCLUSIONS: Chronic tolerance to nicotine is not lost within several weeks of quitting smoking and may not change even after years of abstinence from tobacco use.

Reinforcing effects of nicotine as a function of smoking status.

The authors compared acute nicotine self-administration among 4 groups varying in current or past dependence: dependent smokers, nondependent smokers, ex-smokers who had quit at least 1 year ago, and nonsmokers. Nicotine (0 vs. 12 microg/kg/8 sprays) available by nasal spray was self-administered with a choice procedure. Self-administration also was related to participant characteristics (sex, alcohol and caffeine intake, sensation-seeking score) and to subjective responses to initial nicotine spray exposure. Nicotine self-administration was similar between dependent and nondependent smokers but was greater in those groups than in ex-smokers and nonsmokers, who did not differ from each other. Self-administration was unrelated to most other participant characteristics. In nonsmokers, self-administration was related directly to pleasurable effects but inversely to aversive effects. Few effects were related to self-administration in the other groups.

Subjective responses to nicotine in smokers may be associated with responses to caffeine and to alcohol.

Sensitivity in responses to one drug may relate to sensitivity to other drugs, suggesting broad individual differences in characteristic responsivity across drugs. Data from two separate studies of smokers were reanalyzed to examine associations between acute subjective and cardiovascular effects of nicotine vs. caffeine and between nicotine vs. alcohol. Typical intakes of cigarettes, alcohol, and caffeine were included as covariates when they were correlated with the responses of interest. Significant associations between nicotine and caffeine were seen for most of the subjective measures and for blood pressure responses. Fewer significant associations were observed between nicotine and alcohol. Responses associated between nicotine and both of the other drugs tended to reflect psychomotor stimulation. These results suggest that smokers who are more responsive to some of nicotine's subjective and blood pressure effects are also more sensitive to the same effects of caffeine and, to a lesser extent, of alcohol.

Threshold doses for nicotine discrimination in smokers and non-smokers.

RATIONALE: Tobacco use during initial experimentation often involves modest nicotine exposure, escalating to larger doses and more frequent exposure with the onset of tobacco dependence. Threshold doses for nicotine discrimination therefore may differ between naive and experienced tobacco users. OBJECTIVES: We determined the lowest (threshold) dose of nasal spray nicotine that smokers and non-smokers could reliably discriminate from placebo spray. METHODS: Male and female smokers (n=18) and non-smokers (n=17) were initially trained to discriminate 20 microg/kg from placebo before proceeding to threshold determination sessions, which involved discrimination of progressively lower doses below 20 microg/kg ("descending order" subgroup) or higher doses above 1 microg/kg ("ascending order" subgroup). Threshold was determined by the lowest dose reliably discriminated from placebo (correct on > or =80% of testing trials) and by failure to discriminate the next lowest dose. RESULTS: Threshold doses for nicotine discrimination were low and not different between smokers and non-smokers (median thresholds of 3 versus 2 microg/kg and approximate blood levels of 2.6 versus 1.6 ng/ml, respectively). Thresholds were similar between descending and ascending order subgroups. Several subjective responses differentiated threshold dose from the dose just below threshold, particularly in non-smokers. CONCLUSIONS: Threshold doses for nasal spray nicotine discrimination in humans are low, well below the typical nicotine delivery of most cigarette brands, and may not change after long-term smoking exposure.

The discriminative stimulus and reinforcing effects of nicotine in humans following nicotine pretreatment.

Smokers often report that the first cigarette of the day is the most rewarding, and subsequent smoking is less rewarding. Reduction in smoking enjoyment later in the day may be related to acute tolerance to the discriminative stimulus effects of nicotine. We examined changes in nicotine discrimination behaviour in humans as a function of acute nicotine pretreatment. Male and female dependent smokers (n = 15) were initially trained to discriminate 20 microg/kg nicotine by nasal spray from placebo (0 microg/kg) without nicotine pretreatment. They then were tested on generalization of discrimination across a range of spray doses from 0-20 microg/kg following pretreatment with placebo, moderate dose (14-21 mg) or high dose (28-42 mg) transdermal nicotine. Generalization testing involved both two- and three-response ('novel' option) quantitative procedures. Subjects also engaged in a self-administration phase at the end of each session, involving choices between nicotine (20 microg/kg) and placebo spray. Nicotine pretreatment significantly attenuated nicotine-appropriate responding at higher nicotine spray doses, suggesting acute tolerance, but only in women. Similar results were seen for subjective 'head rush', suggesting this effect may be related to discrimination behaviour in women. However, nicotine pretreatment also increased novel-appropriate responding, especially in men, following intermediate generalization doses, suggesting qualitatively different stimulus effects. Although differences were not significant, nicotine self-administration tended to be inversely associated with nicotine pretreatment dose in men but not in women. These results only modestly support the notion of acute tolerance to the discriminative stimulus effects of nicotine, and even then only in women and not in men.

Dissociation of nicotine tolerance from tobacco dependence in humans.

Chronic functional tolerance to nicotine generally is believed to be associated with processes responsible for tobacco dependence. The dose-related effects of nicotine (0-20 microg/kg by nasal spray) on subjective, cardiovascular, and performance responses were compared among four groups varying in current or past dependence: dependent smokers (21 cigarettes per day for 20 years; n = 45), nondependent smokers (three cigarettes per day for 14 years; n = 12), former dependent smokers (mean of 7 years quit after smoking 25 cigarettes per day for 19 years; n = 17), and life-long nonsmokers (n = 19). Chronic tolerance was determined by a shift to the right, or flattening, of the dose-response curve relative to the curve for nonsmokers. Responses were corrected for plasma nicotine concentration to rule out dispositional tolerance. Chronic tolerance was observed for most subjective responses, but little or none for cardiovascular and performance effects. Tolerance was substantial and virtually identical between dependent and nondependent smokers, whereas tolerance of former smokers was intermediate between nonsmokers and dependent smokers. Identical chronic tolerance between dependent and nondependent smokers indicates that tolerance is not a linear function of smoking exposure and does not require presence of dependence. Thus, the wide variability in daily smoking rate among smokers cannot be attributed to differences in tolerance and must involve other processes of adaptation to nicotine. The modest reversal of tolerance in long-time former smokers suggests that such tolerance reversal is either limited or extremely slow after extended abstinence, despite loss of dependence. These results suggest there is no close link between nicotine tolerance and dependence and question the utility of tolerance as one of the criteria for defining dependence.

Sex differences in the acute effects of cigarette smoking on the reinforcing value of alcohol.

Alcohol consumption acutely increases smoking behavior, but the reverse relationship, the acute effects of smoking on alcohol intake, largely has been ignored. We examined whether smoking acutely increases the reinforcing value of alcohol, first in the absence of recent alcohol intake and then following an alcohol pre-load. Healthy, social-drinking smokers (n = 11 men, 14 women) engaged in a computerized task involving concurrent schedules of reinforcement for beer (FR10, 3 oz (90 ml) per reinforcement) or money (FR5 to FR30, $0.20 per reinforcement) during two sessions, one following day-long ad lib smoking and the other following overnight smoking abstinence. During each session, subjects performed the task in two sets of trials, one before and one after consumption of an alcohol pre-load, with 60 min between sets. To standardize the alcohol pre-load, all subjects were led to believe that they had earned 9 oz (270 ml) of beer after the first trial set, which they then consumed before the second set of trials. Compared to responding during the abstinent session, responding for alcohol during the smoking session was no different before the alcohol pre-load (trial set one) but was significantly greater following the alcohol pre-load (trial set two), although only in men and not women. Subjective sedation after the alcohol pre-load was attenuated during the smoking session in both men and women, but attenuated sedation due to smoking was related to subsequent alcohol-reinforced responding only in men. Additional research is needed to determine the extent to which these effects in men are pharmacological in nature or are conditioned responses to smoking or to consuming a preferred alcoholic beverage.

Effects of training dose and two- versus three-choice testing procedure on nicotine discrimination responding in humans.

RATIONALE: Discrimination of a drug's interoceptive stimulus effects often depends substantially on training and testing conditions. OBJECTIVES: We examined changes in nicotine discrimination behavior in humans as a function of lowering the training dose and of varying the discrimination testing procedure. METHODS: Smokers and never-smokers (n=10 each) were initially trained to discriminate 20 microg/kg nicotine by nasal spray from placebo (0) and tested on generalization of discrimination responding across a range of doses from 0 to 20 microg/kg. Each subsequently learned to reliably discriminate progressively smaller doses of nicotine from placebo until his or her threshold dose for discrimination was identified (mean=2.7 microg/kg). A repeat testing of generalization responding across 0-20 microg/kg was then conducted, using placebo and the subject's threshold dose as training doses. Generalization testing involved both two-choice and three-choice (novel response option) quantitative procedures. RESULTS: A significant shift to the left was seen in nicotine-appropriate responding in the two-choice procedure when the nicotine training dose was lowered (i.e. from the first to the second test of generalization). In the three-choice procedure, however, there was no such leftward shift. Instead, in never-smokers, a flattening of nicotine-appropriate responding occurred with a lowering of the training dose, while novel-appropriate responding significantly increased. The subjective effects of "head rush" and, in never-smokers only, "jittery" also showed a shift to the left in their relationship with nicotine generalization dose when the training dose was lowered. CONCLUSIONS: These results confirm the importance of training and testing conditions on discrimination behavior and subjective drug responses within subjects and demonstrate the utility of the novel-response, three-choice procedure for assessing qualitatively different stimulus effects of novel drug doses.

Effects of central and peripheral nicotinic blockade on human nicotine discrimination.

Nicotine produces interoceptive stimulus effects in humans, which may be critical in understanding tobacco use. It has not yet clearly been demonstrated that discrimination of nicotine, or any drug, in humans is due to its central effects. We compared effects of mecamylamine (10 mg p.o.), a central and peripheral nicotine antagonist, on nicotine discrimination with those of trimethaphan (10-40 microg/kg per min i.v.), a peripheral nicotine antagonist only, and placebo. Smokers (n = 6) were first trained to reliably discriminate 0 versus 20 microg/kg nicotine by nasal spray and then tested on generalization of this discrimination across a range of nicotine doses (0, 3, 6, 12, 20 microg/kg) following antagonist/placebo pretreatment. Nicotine self-administration was also assessed after generalization testing by having participants intermittently choose between nicotine versus placebo spray. Compared with responding following placebo pre-treatment, discrimination of the highest dose of nicotine was significantly attenuated following mecamylamine but not trimethaphan. Similar results were observed for some subjective responses to nicotine. Mecamylamine also tended to increase nicotine self-administration. Consistent with previous animal studies, these results suggest that discriminative stimulus effects of nicotine in humans are mediated at least in part by its central effects.

Influence of acute smoking exposure on the subsequent reinforcing value of smoking.

The reinforcing value of smoking (i.e., the degree to which a smoker will work to obtain smoking) after varying the magnitude of prior smoke exposure in smokers not trying to quit was examined. Eight men and 8 women participated in 5 sessions involving manipulation of prior exposure to smoking: 0, 2, 6, or 12 puffs after overnight smoking abstinence or ad-lib smoking before the session. After exposure, participants engaged in a computer task involving concurrent schedules of reinforcement for smoke puffs (16% all trials) versus money (4-64%). Only the greatest amount of prior exposure (ad lib) produced a significant reduction in subsequent responding for smoke puffs. No exposure condition significantly increased responding above that for 0 puffs, indicating no priming effect. By contrast, self-report measures of desire to smoke and amount of money participants would pay for a cigarette declined sharply with greater prior exposure. These measures were correlated only weakly with smoke-reinforced responding on the behavioral task, suggesting that subjective versus behavioral measures assess different dimensions of smoking's reward value.

Nicotine preference in smokers as a function of smoking abstinence.

Overnight smoking abstinence increases desire to smoke and intensity of smoking behavior in smokers, but it is not completely clear that this reflects an increase in reinforcement from the psychoactive effects of nicotine per se. We examined choice of nicotine vs. placebo via nasal spray (Study 1) and nicotine vs. nonnicotine cigarette puffs (Study 2) in separate groups of smokers during each of two sessions, following overnight abstinence vs. no abstinence. In each study, subjects followed a forced choice procedure in which they were instructed to self-administer six sprays/puffs from between the two nasal sprays/cigarettes every 15 min for 2 h following initial exposure to each. In Study 1, choice of nicotine spray (1.5 micrograms/kg per spray) increased significantly following abstinence vs. no abstinence (47 +/- 6% vs. 34 +/- 5%, respectively, p < 0.05). This shift in choice was more pronounced in the subset of smokers (choosers, n = 9 out of 24) who selected nicotine on more than 50% of choices on the abstinent day. Choosers exhibited greater responses to initial nicotine exposure on positive (e.g., pleasant, vigor) but not aversive (e.g., jittery, uneasy) subjective measures, suggesting that greater positive reinforcement from nicotine per se predicted subsequent choice. In Study 2, abstinence similarly increased choice of nicotine vs. nonnicotine cigarette puffs (82 +/- 6% vs. 64 +/- 8%, p < 0.05), although nearly all subjects (12 of 13) preferred the nicotine cigarette following abstinence. These results indicate that choice of nicotine per se, isolated from tobacco smoke, increases significantly after overnight tobacco abstinence.

Gender, dietary restraint, and smoking's influence on hunger and the reinforcing value of food.

Smoking may enhance satiety following meal consumption, thereby reducing subsequent eating (i.e., between-meal snacks), especially in women high in dietary restraint. Female smokers (n = 20, 10 high and 10 low restraint) and male smokers (n = 10) participated in two sessions, involving overnight abstinence from food and smoking (smoking abstinence day) or from food only (smoking day), in a within-subjects design. The reinforcing value of food was determined by the number of responses made to obtain food reinforcers (100-kcal snack portions) vs. money using a concurrent schedules computer task. Subjects were given a small caloric load on each day followed by access to food vs. money. On the smoking day, subjects were allowed to smoke every 30 min during the session as well as ad lib before the session. Self-reported hunger was also assessed upon arrival (after fasting) and following the caloric load during each session. Results indicated no effect of smoking on initial hunger rating, after fasting, but hunger ratings following the caloric load declined significantly more during smoking vs. abstinence days for all subjects, consistent with an enhancement of postmeal satiety due to smoking. There was no overall main effect of smoking on food-reinforced responding. However, responding for food was significantly less during the smoking vs. abstinence days for high-restraint females only and not for low-restraint females or for males. These findings indicate that smoking's acute influence on reducing food intake does not reflect a broad gender difference but may be specific to dietary restraint.

Mammary 5'deiodinase (5'D) during the breeding cycle of the rat: indirect evidence that 5'D type I is specific to the alveolar epithelium.

The present study analyses the activity of 5'deiodinases type I and II in mammary gland during the breeding and estrous cycle of the rat, and includes indirect evidence that 5'D-I is present only in the alveolar epithelium. Data show that the mammary gland exhibits 5'D-II activity throughout the developmental period and its activity varies along the allometric growth of the gland. 5'D-I is detected during the differentiation stages of the alveolar epithelium (puberty, late pregnancy) and its activity rises significantly (10-fold) 24 h after delivery. Data also show that 5'D-I activity is not present in the fat pads of the gland. These findings suggest that during its differentiation and functional stages, the mammary gland requires an elevated and compartmentalized production of T3.