The author postulates a need of individual evaluation of experimental data characterizing emotional stress. In typical conflict situations inducing emotional stress, there are animals resistant or predisposed to disturbance of different physiological functions. Prognostic criteria of individual resistance of animals to stressors are presented. Stress resistance depends in large on neuromediators and neuropeptides content, in particular Substance P, a peptide responsible for delta-sleep, and beta-endorphin, in brain structures and peripheral tissues. It is emphasized that individual estimation of clinical indices of emotional stress is needed.