Relaxation, imagery, and neuroimmunomodulation.

Thirty undergraduates screened for high absorption ability were randomly assigned to three conditions. The first condition consisted of relaxation alone (progressive muscle relaxation and focused breathing). The second one combined this same relaxation training with mental imagery of the immune system. The third condition served as an alertness or mild arousal control; in a vigilance task subjects discriminated between tones presented in variable inter-trial intervals. Subjects reported trial levels of tension and daily stress. Before and after the protocols, which lasted about 1 hour, salivary immunoglobulin A (SIgA), cortisol and catecholamines (saliva and plasma), mood states, and power motivation were assessed. Afterwards, subjects doing relaxation alone and with imagery had a higher level of SIgA than did the vigilance task control group, with a large effect size. When the influence of plasma cortisol was controlled, this immune effect size increased by half, mainly by doubling the SIgA level after relaxation alone. SIgA was significantly and negatively correlated with saliva norepinephrine. The saliva and plasma levels for the neuroendocrine variables appear to be independent. Yet some saliva measures (e.g., epinephrine) did correspond highly with other plasma measures (e.g., norepinephrine).