Pain complaints are frequent in psychiatric and primary care settings. Furthermore, in pain clinic, depression and pain disorders are common comorbidities. On the other hand, several antidepressants are effective in the management of chronic pain and in alleviating pain complaints in depressed patients.

In this lecture, we summarize the current knowledge with regard to the use of antidepressants in chronic pain conditions and in pain as a somatic complaint in depression. We review the pharmacological mechanisms and the neurobiological substrate of these properties.

To give arguments for the recognition of antidepressants as useful tool to treat pain in depression and depression in chronic pain patients, and to provide information about the right choice of an antidepressant in chronic pain.

The monoaminergic system participates both in the regulation of mood and in the modulation of pain. Antidepressants have several properties modulating monoamines. Some of these properties are critical to understand the mechanisms of action of these compounds in chronic pain and in alleviating pain as a somatic symptom in depressed patients. The discussion about whether antidepressants alleviate pain acting on mood or pain transmission is a matter open to discussion, however there is no doubt about the utility of these drugs in pain. Recent studies in modified genetic animals reinforce the idea the not only monoamines but also other neurotransmission systems underlie these effects.