Psychobiology of pain suppression

Pain suppression is based on a variety of mechanisms that are best describe d by a psychobiological perspective.:This is also true for the type of pain suppression which results in the phenomenon "pain: suppresses pain": The s upra-spinal neuronal mechanism, called "diffuse noxious inhibitory controls " (DNIC), is activated quickly by strong and sustained pain and leads to an anatomically generalized (heterotopic) reduction of pain sensitivity outsi de the original area of pain. This mechanism which helps to prevent a sprea d of pain seems to be defective in some chronic pain syndromes. A stower ac ting variant of pain suppression is triggered by psychological and physical stress. The delayed onset and the duration:of minutes suggest a hormonal m echanism of "stress analgesia". "Stress hormones" (ACTH, beta-endorphin and cortisol) are indeed released. concurrently with stress analgesia. However , the direct administration of stress hormones does not-produce analgesia. Some sorts of stress analgesia are opioid-dependent because they are preven ted by administration of opiate antagonists. The described fast and slow as well as further variants of pain suppression permit a highly flexible:regu lation of pain Sensitivity which may be altered by any, even by therapeutic interventions.