Some 25 million Americans suffer from depression, and twice as many suffer from chronic pain. Not surprisingly, a significant number of chronic pain sufferers also have depression. As a matter of fact, some who suffer chronic pain don’t suffer physical ailments at all. Instead, the underlying depression presents itself as physical pain. The reason: Pain and depression share similar pathways. Both pain and depression alter the metabolism of two brain neurotransmitters (chemicals) called serotonin and norepinephrine.

One remedy for treating chronic pain is to use anti-depressants, which restore the balance of the two above chemicals in the brain. Those who suffer pain will perceive a decrease in pain.

Both pain and depression also decrease REM sleep, which is needed for proper functioning. The use of narcotics or excessive alcohol further upsets REM sleep. This may lead to the worsening of pain and depression, creating a vicious cycle.