The self-assessment of perceived immune status is important, as this subjective observation leads individuals to decide whether or not to seek medical help or adapt their lifestyle. In addition, it can be used in clinical settings and research. The aim of this series of studies was to develop and validate a short questionnaire to assess perceived immune functioning. Five surveys were conducted among Dutch and International young healthy adults (18–30 years old), and two others among older age groups with various health complaints. For the first study, an existing immune functioning scale was modified and elaborated resulting in 23 immune-health-related items, of which the occurrence was rated on a 5-point Likert scale. A student sample was surveyed, and the results were used to shorten the 23-item listing into a 7-item scale with a predictive validity of 85%. Items include “sudden high fever”, “diarrhea”, “headache”, “skin problems (e.g., acne and eczema)”, “muscle and joint pain”, “common cold” and “coughing”. The scale is named Immune Status Questionnaire (ISQ), and it aims to assess perceived immune status over the preceding year. The second study revealed that the ISQ score correlated significantly with a 1-item perceived immune functioning (r = 0.383, p < 0.0001). In the third study, the final Likert scale descriptors were determined (“never”, “sometimes”, “regularly”, “often” and “(almost) always)”. The fourth study showed that the test–retest reliability of the ISQ is acceptable (r = 0.80). The fifth study demonstrated the association of ISQ scores with various neuropsychological and health correlates in an international sample, including perceived health and immune fitness, as well as levels of stress, fatigue, depression and anxiety. Study 6 demonstrated significant associations between ISQ scores and experiencing irritable bowel syndrome (IBS) symptoms in a sample of insomnia patients. Study 7 compared the effect of a dietary intervention in participants reporting “poor health” versus “normal health”. It is shown that ISQ scores can differentiate between those with poor and normal health, and that an effective intervention is associated with a significant improvement in ISQ scores. Data from Study 7 were further used to determine an ISQ cut-off value for reduced immune functioning, and a direct comparison with 1-item perceived immune functioning scores enabled constructing the final scoring format of the ISQ. In conclusion, the ISQ has appropriate face, content, and construct validity and is a reliable, stable and valid method to assess the past 12 month’s perceived immune status.

The limited number of available studies that examined the pathology of alcohol hangover focused on biomarkers of alcohol metabolism, oxidative stress and the inflammatory response to alcohol as potentially important determinants of hangover severity. The available literature on alcohol metabolism and oxidative stress is reviewed in this article. The current body of evidence suggests a direct relationship between blood ethanol concentration and hangover severity, whereas this association is not significant for acetaldehyde. The rate of alcohol metabolism seems to be an important determinant of hangover severity. That is, fast elimination of ethanol is associated with experiencing less severe hangovers. An explanation for this observation may be the fact that ethanol—in contrast to acetaldehyde—is capable of crossing the blood–brain barrier. With slower ethanol metabolism, more ethanol is able to reach the brain and elicit hangover symptoms. Hangover severity was also significantly associated with biomarkers of oxidative stress. More oxidative stress in the first hours after alcohol consumption was associated with less severe next-day hangovers (i.e., a significant negative correlation was found between hangover severity and malondialdehyde). On the contrary, more oxidative stress at a later stage after alcohol consumption was associated with having more severe next-day hangovers (i.e., a significant positive correlation was found between hangover severity and 8-isoprostane). In conclusion, assessment of biomarkers of alcohol metabolism suggests that fast elimination of ethanol is associated with experiencing less severe hangovers. More research is needed to further examine the complex interrelationship between alcohol metabolism, the role of acetaldehyde and oxidative stress and antioxidants, and the pathology of the alcohol hangover.

An increasing number of studies are focusing on the inflammatory response to alcohol as a potentially important determinant of hangover severity. In this article, data from two studies were re-evaluated to investigate the relationship between hangover severity and relevant biomarkers of alcohol metabolism, oxidative stress and the inflammatory response to alcohol. Hangover severity was significantly and positively correlated with blood concentrations of biomarkers of the inflammatory response to alcohol, in particular, Interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and C-reactive protein (CRP). At 4 h after alcohol consumption, blood ethanol concentration (but not acetaldehyde) was significantly and positively associated with elevated levels of IL-6, suggesting a direct inflammatory effect of ethanol. In addition, biomarkers of oxidative stress, i.e., malondialdehyde and 8-isoprostrane, were significantly correlated with hangover severity, suggesting that oxidative stress also contributes to the inflammatory response. The timing of the assessments suggests initial slow elimination of ethanol in the first hours after alcohol consumption. As a consequence, more ethanol is present in the second half of the night and the next morning, which will elicit more oxidative stress and a more profound inflammatory response. Together, these processes result in more severe hangovers.

The 2010 Alcohol Hangover Research Group consensus paper defined a cutoff blood alcohol concentration (BAC) of 0.11% as a toxicological threshold indicating that sufficient alcohol had been consumed to develop a hangover. The cutoff was based on previous research and applied mostly in studies comprising student samples. Previously, we showed that sensitivity to hangovers depends on (estimated) BAC during acute intoxication, with a greater percentage of drinkers reporting hangovers at higher BAC levels. However, a substantial number of participants also reported hangovers at comparatively lower BAC levels. This calls the suitability of the 0.11% threshold into question. Recent research has shown that subjective intoxication, i.e., the level of severity of reported drunkenness, and not BAC, is the most important determinant of hangover severity. Non-student samples often have a much lower alcohol intake compared to student samples, and overall BACs often remain below 0.11%. Despite these lower BACs, many non-student participants report having a hangover, especially when their subjective intoxication levels are high. This may be the case when alcohol consumption on the drinking occasion that results in a hangover significantly exceeds their “normal” drinking level, irrespective of whether they meet the 0.11% threshold in any of these conditions. Whereas consumers may have relative tolerance to the adverse effects at their “regular” drinking level, considerably higher alcohol intake—irrespective of the absolute amount—may consequentially result in a next-day hangover. Taken together, these findings suggest that the 0.11% threshold value as a criterion for having a hangover should be abandoned.

Background: Irritable bowel syndrome (IBS) can have a significant negative impact on quality of life, mood and wellbeing. The aim of this study was to investigate the association between experiencing IBS symptoms and insomnia, and perceived health status. Method: An online survey was conducted among n = 1950 Dutch university students (83.6% women). IBS was assessed with the Birmingham IBS Symptom Questionnaire, quality of life with the WHO-5 wellbeing index, and sleep outcomes with the SLEEP-50 questionnaire. Perceived immune functioning and general health were assessed using 1-item scales. Results: IBS symptom severity was significantly associated with insomnia complaints (r = 0.32, p = 0.0001), sleep quality (r = −0.21, p = 0.0001), sleep onset latency (r = 0.11, p = 0.0001) and the number of nightly awakenings (r = 0.24, p = 0.0001). Total sleep time was not significantly associated with IBS symptom severity. Significant correlations were also found between IBS symptom severity and perceived general health (r = −0.30, p = 0.0001), perceived immune functioning (r= −0.25, p = 0.0001), and quality of life (r = −0.24, p = 0.0001). Conclusions: Experiencing IBS complaints is associated with reduced perceived immune functioning, a poorer perception of general health, and sleep disturbances. These effects are reflected in a significantly lower reported quality of life in subjects with more IBS and/or sleep complaints.

Assessments in blood and saliva suggests that the amount of ethanol present in the first hours after alcohol consumption and into the following morning is associated with hangover severity. The current analysis determines how ethanol elimination rate is related to hangover severity reported throughout the day. n = 8 subjects participated in two studies. The first was a naturalistic study comprising an evening of alcohol consumption. Hangover severity was assessed hourly from 10 a.m. to 4 p.m., using a 1-item hangover severity scale ranging from 0 (absent) to 10 (extreme). The second study comprised a highly controlled alcohol challenge to reach a breath alcohol concentration (BrAC) of 0.05%. Breathalyzer tests were conducted every 5 min until BrAC reached zero. The ethanol elimination rate, expressed in BrAC%/hour, was computed by dividing the peak BrAC (%) by the time to BrAC of zero (h). At 11:00, 13:00, and 14:00, there were significant negative partial correlations, controlling for estimated BrAC, between ethanol elimination rate and hangover severity. The findings suggest that drinkers with a faster ethanol elimination rate experience less severe hangovers. The observations should be confirmed in a larger sample of subjects who participate in a single study that assesses both hangover severity and ethanol elimination rate.