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.

Nasal spray nicotine replacement suppresses cigarette smoking desire and behavior.

The effects of short-term nasal spray nicotine replacement in suppressing desire to smoke and ad libitum cigarette smoking behavior were evaluated in male and female smokers. In study I, 10 male and 10 female smokers received intermittent doses of 0, 7.5, 15, and 30 micrograms/kg nicotine by way of measured-dose nasal spray, with each dose on a separate day. Self-reported desire to smoke was significantly suppressed by each nicotine dose compared with placebo, but there were no significant differences among nicotine doses or between men and women. In study II, eight male and eight female smokers received 0, 15, and 30 micrograms/kg nicotine intermittently and were allowed to smoke their preferred brands of cigarettes ad libitum. Similar to study I, nicotine replacement significantly suppressed number of cigarettes smoked, number of puffs, and carbon monoxide boost and increased latency to smoking, but there were almost no significant differences between the two nicotine doses. Magnitude of smoking suppression attributable to 15 micrograms/kg tended to be greater in men than in women. However, plasma nicotine concentrations were significantly higher after 15 and 30 micrograms/kg versus placebo, suggesting only partial compensation in smoking behavior with short-term nasal nicotine replacement. These findings support the idea that short-term nicotine replacement decreases smoking desire and behavior, but the findings indicate that smoking behavior is partly influenced by factors other than nicotine regulation.

Acute thermogenic effects of nicotine combined with caffeine during light physical activity in male and female smokers.

The thermogenic effects of nicotine and caffeine during physical activity compared with rest were examined in male and female smokers (n = 10 each). During eight sessions, nicotine (15 micrograms/kg) or placebo was given via measured-dose nasal spray intermittently after consumption of decaffeinated coffee with or without added caffeine (5 mg/kg), followed by assessment of energy expenditure by indirect calorimetry while subjects engaged in standardized, low-intensity cycle ergometer riding (activity) or remained at quiet rest. Results indicated significant thermogenic effects of nicotine and caffeine individually, with the combination of nicotine and caffeine producing additive effects. Expenditure attributable to nicotine, caffeine, or their combination was significantly enhanced during activity compared with rest, but only for males and not females. Plasma nicotine concentrations were influenced by activity and caffeine, but these pharmacokinetic changes did not appear to explain the differences in expenditure. These findings suggest a sex difference in thermogenic effects of nicotine and caffeine during casual physical activity and potentially explain some of the apparent individual variability in expenditure due to tobacco smoking.

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.

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.

Subjective and cardiovascular responses to nicotine combined with caffeine during rest and casual activity.

Although nicotine and caffeine have separately been shown to acutely increase subjective arousal, their combined effects are unclear. Furthermore, their effects during casual physical activity, the condition under which individuals usually experience nicotine and caffeine, are unknown. Smokers who were regular coffee drinkers (n = 19, 9 males, 10 females) participated in eight morning sessions, involving nicotine/placebo, caffeine/no caffeine, and rest/physical activity (i.e. 2 x 2 x 2 within-subjects design). Nicotine (15 micrograms/kg) or placebo was given via measured-dose nasal spray intermittently after consumption of decaf coffee with or without added caffeine (5 mg/kg), followed by subjective [Profile of Mood States (POMS), Stress-Arousal Checklist, visual analog scales] and cardiovascular (heart rate, blood pressure) measures. Casual physical activity was standardized by low-intensity bicycle riding while sitting comfortably. Results indicated significant subjective and cardiovascular effects of nicotine and caffeine individually, with the combination of nicotine and caffeine generally producing additive or greater than additive effects for each measure. However, activity mediated some of the subjective effects of nicotine, as nicotine appeared to be "stimulating" during rest but not during activity. There were no differences between males and females. These findings suggest that nicotine per se and caffeine generally have additive subjective and cardiovascular effects, and that nicotine may influence subjective stimulation differentially depending on whether a smoker is resting or engaged in casual activity.

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.

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.

"Paradoxical" effects of smoking on subjective stress versus cardiovascular arousal in males and females.

Cigarette smoking has sometimes been found to decrease subjective stress while simultaneously increasing cardiovascular arousal, contrasting effects referred to as the "nicotine paradox." The present study assessed acute effects of cigarette smoking on subjective stress vs. cardiovascular arousal in minimally deprived male and female smokers who smoked (n = 16) or sham smoked (unlit cigarette, n = 15) and a comparison group of male and female nonsmokers (n = 12) who sham smoked only. All subjects participated in two sessions (high- or low-challenge computer task) in which they smoked or sham smoked prior to each of two 20-min task trials. Results showed reduced subjective stress in smoking smokers compared with sham-smoking smokers during the high- but not low-challenge task. However, this stress reduction occurred only immediately after smoking and dissipated midway through each trial. In males, smoking appeared to reduce stress below that of nonsmokers, while smoking in females attenuated stress only partially to the level of nonsmokers. In contrast with the attenuated stress effects, cardiovascular arousal (especially heart rate) was increased immediately after smoking during both tasks and did not appear to be directly related to subjective changes. These findings suggest that the stress-reducing effects of smoking may be transient, situationally specific, partly gender dependent, and dissociated from the effects of smoking on cardiovascular arousal.

Tobacco abstinence, smoking cues, and the reinforcing value of smoking.

One definition of the reinforcing value of a drug is the degree to which an organism will work to obtain it. Male and female smokers (n = 8 each) engaged in a task involving concurrent schedules of reinforcement for responding to receive cigarette puffs versus money on four occasions, following overnight abstinence versus no abstinence and in the presence of a lit cigarette (smoking "cue") or with no cigarette (2 x 2 design). Reinforcement schedule for puffs ranged from variable ratio 4 (VR4) to VR32, with schedule order during the first five trials (VR4 first, VR32 first) counterbalanced and repeated in reverse sequence during the second five trials. Schedule for money remained at VR4 during all trials. Results indicated significantly greater responding for puffs after overnight abstinence and in the presence of the smoking cue, although effect of the cue was specific to the "leaner" VR schedules (VR16, VR32). Unexpectedly, not only was reinforcement schedule for puffs a significant determinant of responding, but the order of these schedules (i.e., VR4 first vs. VR32 first) produced a significant overall difference in responding for puffs, especially in the presence of the cue. There was no difference in responding between males and females. These findings indicate that the reinforcing value of smoking is increased by overnight abstinence, the presence of a lit cigarette under lean reinforcement conditions, and the order in which reinforcement schedules are presented.

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.

Comparison of acute subjective and heart rate effects of nicotine intake via tobacco smoking versus nasal spray.

Nicotine is the primary psychoactive constituent of tobacco smoke, but it is not clear whether the reinforcing effects of cigarette smoking can be attributed solely to nicotine intake. In this study, two groups of male and female smokers participated in three sessions involving intermittent exposure to moderate low, or no nicotine doses via controlled tobacco smoking ("smoke," n = 20) or measured-dose nasal spray ("spray," n = 16). Visual analog scales of subjective effects (VAS) and heart rate (HR) were obtained within 5 min of each dosing. Plasma nicotine levels indicated comparable dosing between methods. For both methods, there were significant nicotine dose effects for most subjective measures and HR. More importantly, the pattern of effects across doses was virtually identical between methods, as nicotine intake via smoking or spray significantly increased HR and the VAS scales of Head Rush and Dizzy, decreased Hunger and Desire to Smoke, and had no effect on Comfortable, Jittery, or Relaxed. These results suggest that rapid nicotine uptake by novel methods may provide effects very similar to nicotine intake by smoking.

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.

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.

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.

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.