PsychoNeuroEndocrinology (PNEI) is the most recent medical science that studies the neuroendocrine biochemistry, which mediates the emotions and the states of consciousness and their influence on the status of health through a regulation of the immune responses.

The discoveries of PNEI would have not only a medical and scientific significance, but also a philosophic relevance, since they offer an answer to the problem of the relationship between biological body and spirit, as considered as the self-consciousness, by proposing a reciprocal influence of the neuroimmunobiochemistry on the status of consciousness and of the psycho-spiritual status on the neuro-immune interactions.

According to recent advances in the areas of the neurosciences and PNEI itself, it is possible to identify in the complex brain neuronal interactions a pyramidal functional structure, consisting of three fundamental levels of neuron relationships, represented by the neurotransmission, the neuromodulation, and the psychoneuromodulation, which are the expression of three different grades of brain neuronal integration.

PNEI results have demonstrated that the psych-neuroendocrine functions related to the perception of sexual pleasure and spiritual life play a direct anticancer activity due to either anti-proliferative action exerted by both pineal idols and cannabinoid agents, or stimulation of the antitumor immunity.

Finally, by considering the relation between the two major brain systems of the psychoneuromodulation and the endocrine glands, the opioid system is more linked to the pituitary gland, as demonstrated by its activation in stress conditions, whereas the cannabinergic system, which is functionally linked to the pineal, is activated in conditions of pleasure and spiritual perception.

The opioid system has been proven to inhibit the anticancer immune response, whereas the cannabinoid-pineal functional unit plays a stimulatory role on the antitumor immunity.

In contrast, the activation of the opioid system allows an inhibition of the secretion of both IL-2 and IL-12, and this finding could explain the stimulatory influence of stress, depression, and pain on tumor onset and development.

These cancer-related immunoendocrine alterations are not a simple epiphenomenon, but on the contrary they represent the cause responsible at least in part for cancer progression related to the immunosuppressive status of patients. Then, cancer-related immunosuppression would mainly depend on an altered psychoneuroendocrine regulation of the immune system, rather than to be the expression of a primary damage of immune cells themselves.