Pain and pain syndromes.

The two main categories of pain, nociceptive and neuropathic, are caused by tissue damage and nerve damage respectively. Psychogenic pain is also described in the literature but it is becoming a pejorative term as the concept of central control of pain is now gaining momentum. There is considerable overlap in brain areas that deal with pain and where mood disorders develop. Some neurotransmitters, e.g. serotonin and noradrenaline, are involved in receiving and processing signals and regulate mood as well. It is no coincidence that many drugs used to treat mood disorders are effective when used for pain relief. This article highlights this interplay of neurotransmission and affective/pain symptomatology.