The purpose of this study is to demonstrate the effects of awareness on experimentally induced anxiety. Forty college undergraduates were conditioned with a mild electric shock as the UCS (unconditioned stimulus) and a tone a s the CS (conditioned stimulus). After conditioning, the experimental group was taught to discriminate between the CS and six other tones which were both higher and lower in frequency than the CS. The control group was not given these learning trials. After learning to discriminate the tones, the experimental subjects had a higher GSR (Galvanic Skin Response) to the seven tones as compared to the control group. The discrimination process thus facilitated an association among the tones. This increase in anxiety was relatively greater with the passage of time as the experimental subjects also had a higher GSR to the seven tones 24 hours after conditioning compared with 30 minutes after conditioning. These increases, however, were not significant in all cases.

Background: Prior studies show that sickness induces anxiety as rated by subjective reports but have not linked this to overt behavior in humans. This study investigates the expression of distress during experimental sickness, its relation to self-reported anxiety, and the moderating role of gender in the association between overt distress and self-rated anxiety. Methods: 21 participants (18-34 yrs, 10 women) were semi-randomly chosen from a placebo-controlled, double-blind, within-subject experiment, in which participants were intravenously injected with a bacterial endotoxin lipopolysaccharide (LPS, 0.8 ng/kg body weight) triggering a transient inflammatory reaction and an acute state of sickness. In the current study, we coded the participants’ expression of moans, sighs and deep breaths (overt distress) during sickness from the video recordings of the experiment and analyzed these parameters in relation to the state part of the State Trait Anxiety Inventory (Spielberger et al., 1979) that was collected during the experiment. Results: The frequency of overt distress increased strongly during experimental sickness (1-3h post-injection of LPS) compared to baseline. The level of overt distress was not related to subjective feelings of anxiety. No clear difference was found between men and women in the frequency of expressed distress during sickness. Interestingly however, there was an inverted relation between anxiety and the expression of distress in women, so that women who reported higher anxiety expressed less distress overtly (ß = -0.52, p = 0.018). Conclusions: Experimental sickness strongly induces an increase of moans, sighs and deep breaths, but these are not directly associated with the level of state anxiety reported. The results also suggest that moans, sighs and deep breaths might have a different function in men and women.

Several studies have shown the influence of ovarian hormones on the GABAergic system. As women are naturally exposed to monthly fluctuation of these hormones, it is possible that their response to benzodiazepnes also change over the ovarian cycle. Considering that anxiety disorders are most common in women and therefore they receive more prescriptions for benzodiazepines, this study aimed to evaluate the possible influence of the ovarian cycle of healthy women on the acute effect of diazepam. For that, 40 subjectively healthy women were selected and allocated to two different groups, according to their ovarian cycle phase (follicular or luteal). Both groups were submitted to the Video-Monitored Stroop Color-Word Test (VMSCWT), an experimental model of anxiety, under the influence of diazepam (10 mg) or placebo. Psychological parameters (subjective scales of anxiety) and physiological parameters (heart rate and gastrocnemius electromyogram) were evaluated throughout the test. The results showed that, in the follicular phase, women did not respond to the anxiolytic action of diazepam, although a sedative effect was observed, while in the luteal phase, there was no response to either sedative or anxiolytic actions. As a control of the experimental conditions, a group of 18 men was also submitted to the VMSCWT. The results confirmed that both the anxiogenic test and the administered drug were working as expected, since diazepam managed to prevent the anxiety induced by the test. Therefore, the present findings indicate that the ovarian cycle can alter the effects of the acute administration of diazepam, which can vary from no effect to sedation, without going through anxiolysis / Diversos estudos têm mostrado a influência dos hormônios ovarianos no sistema GABAérgico. Como as mulheres são naturalmente expostas à flutuação destes hormônios, é possível que elas apresentem a resposta a benzodiazepínicos alterada ao longo do ciclo ovariano. Estas observações adquirem um significado ainda maior quando se considera que os transtornos de ansiedade são mais comuns em mulheres e, por isso, elas recebem mais prescrições destas drogas. Sendo assim, o presente estudo teve como objetivo avaliar a possível influência do ciclo ovariano de mulheres saudáveis no efeito agudo do diazepam. Para tanto, 40 mulheres subjetivamente saudáveis foram selecionadas e aleatoriamente alocadas para dois grupos, de acordo com a fase do ciclo ovariano (folicular e lútea). Esses grupos foram submetidos ao Teste de Stroop Monitorado por Vídeo (TSMV), um modelo experimental de ansiedade, sob o efeito de 10 mg de diazepam ou placebo. Parâmetros psicológicos (escalas subjetivas de ansiedade) e parâmetros fisiológicos (freqüência cardíaca e eletromiograma do gastrocnêmio) foram avaliados ao longo do teste. Os resultados mostraram que as mulheres na fase folicular não responderam à ação ansiolítica do diazepam, embora o efeito sedativo tenha sido observado. Já as mulheres na fase lútea não responderam nem à ação ansiolítica, nem a ação sedativa do diazepam. Como controle das condições experimentais, um grupo de 18 homens subjetivamente saudáveis também foi submetido ao TSMV. Os resultados confirmaram que tanto o teste ansiogênico quanto a droga administrada estavam funcionando conforme o esperado, uma vez que o diazepam preveniu a ansiedade eliciada pelo teste neste grupo. Portanto, os resultados sugerem que o ciclo ovariano pode alterar os efeitos da administração aguda de diazepam, sendo que tais efeitos podem variar de nenhum efeito à sedação, sem passar pela ansiólise.