Neurobiological and clinical relationship between psychiatric disorders and chronic pain.

Pain is one of the most ubiquitous problems of today's world, its impact being far-reaching. Current conceptualizations of pain medicine adopt a bio-psycho-social perspective. In this model, pain is best described as an interactive, psycho-physiological behavioral pattern that cannot be divided into independent psycho-social and physical components. Neurophysiologic substrates of the pain experience can be broken down into the pain transmission elements emanating from peripheral, spinal, and supra-spinal processes. There are many complex mechanisms involved in pain processing within the central nervous system, being influenced by genetics, interaction of neurotransmitters and their receptors, and pain- augmenting and pain-inhibiting neural circuits. The patient's emotional experiences, beliefs and expectations may determine the outcome of treatment, and are fully emphasized in the focus of treatment interventions. There are several common psychiatric disorders accompanying and complicating the experience of pain that warrant clinical attention and that can be the focus of psychiatric treatment. These include depression, anxiety, sleep disorders, somatoform disorders, substance-related disorders and personality disorders. Complex and disabling pain conditions often require comprehensive pain treatment programs, involving interdisciplinary and multimodal treatment approaches. There are many roles that the psychiatrist can perform in the assessment and treatment of the patients with pain, individually tailored to meet the specific needs of the patient. Rational poly-pharmacy is of a high importance in the treatment of patients with chronic pain, with antidepressants and anticonvulsants contributing as the important adjuvant analgesic agents.