Laughing can apparently reduce stress and improve NK cell activity, at least temporarily. a buffer or moderator of the effects of daily hassles on SIgA (8). However, this supposition proposed by Martin and Dobbin (8) was not supported by their subsequent study that attempted to document the moderating effect of sense of humor on the relationship between exam stress and a variety of immune measures. Dobbin and colleagues (9,10), examined the effect of three psychological variables (Type A, Locus of Control and Sense of Humor measured by CHS) on immune functioning following examination stress. The results indicated that, as expected, exam stress produced significant immune suppression as measured by decreases in T-cell response to various mitogens, decreased IL-1beta levels ( 0.01) and decreased interferon gamma levels ( 0.05). However, the effect of exam stress was not modified by sense of humor or any of the measured psychological variables used. The authors concluded that the role of psychological traits as moderators of stress should be questioned (9,10). While this conclusion appears too broad, considering the bulk of literature to support the role of other psychological factors as stress modifiers, it does call into question the ability of sense of humor (at least as measured by CHS) to moderate the effects of stress on physiological functioning. Exposure to Humor, Subsequent Laughter and Salivary IgA In order to determine if simply exposing people to a humorous situation can result in immunoenhancement, a few small studies have been conducted using humor videos. In a randomized crossover design, 10 college students viewed two videos, a humorous video and an instructional video (used as a control) (11). The results of exposure to a humorous Sinomenine hydrochloride video and sense of humor (measured by CHS) on SIgA levels were examined. Sense of humor scores on the CHS were positively correlated ( 0.05) with SIgA levels before viewing the videos, demonstrating that subjects with greater sense of humor also had increased salivary IgA, but scores on the CHS were actually negatively correlated with increases in SIgA ( 0.10) following the humorous video. An attempt to explain this confounding finding was suggested by the authors, in that as the subjects with higher humor scores had higher baseline SIgA before the film, SIgA may not have Rabbit Polyclonal to COX19 been able to increase as much from the intervention, due to a possible ceiling effect. But given the conflicting data obtained when examining the relationship between sense of humor and immune function, it may be that sense of humor does not have a significant effect upon this physiological outcome measure. On the positive side, the findings did demonstrate that subjects had significantly increased SIgA levels ( 0.025) after watching the humorous video (= 45, = 34, = 62), subjects salivary IgA levels increased significantly after a brief humorous stimulus ( 0.005). These results Sinomenine hydrochloride clearly support the immunoenhancing actions of exposure to a brief humorous stimulus on SIgA. Again, the influence of sense of humor on SIgA levels was less clear. In an attempt to overcome possible problems due to instrumentation, sense of humor was measured using both SHRQ and CHS. Contrary to Dillon’s findings, in study number one, scores on the humor scales were unrelated to baseline SIgA, while scores on the CHS were positively related to increases in SIgA following the stimulus ( 0.02). In study number 2 2, no significant correlation was found between sense of humor and pre- or post-SIgA levels; and in study number 3 3, scores on the SHRQ were only marginally related to increases in post-stimulus SIgA ( 0.10). In summary, the effect of sense of humor on SIgA and its possible interaction with the humorous stimulus is not clearly supported. One investigation reported that sense of humor was negatively correlated with increases in SIgA following the humorous stimulus (11), two others found subjects with greater sense of humor scores had larger increases in SIgA following the humorous stimulus (6), and lastly one reported sense of humor was not significantly related to SIgA levels before or following a humorous stimulus (6). On the other hand, the effect of exposure to humor stimulus on salivary IgA was supported. However, it should be noted that the use of salivary IgA as a measure of immune function has been questioned by some authors (12,13), due to variations in individual saliva flow rate and the use of stimulated and non-stimulated samples in some studies. In addition, the clinical significance of increased levels of salivary IgA is questionable. Therefore, this body of research should be viewed Sinomenine hydrochloride with some caution and needs replication using a more valid and reliable measure of immune function. Exposure to Humor, Subsequent Laughter and.