The Relationship Between
Clinical Depression and Chronic Pain
Study of Brain
Activity of Fibromyalgia Patients Supports Treating Depression and Physical
Pain Independently, Even When They Co-Exist
Does clinical depression bring about chronic pain? Or does pain lead to
depression? Because these two conditions frequently co-exist—30 to 54
percent of patients with major depressive disorder also suffer persistent
physical pain—there has been much speculation about whether one causes
the other or whether a common underlying factor provokes both. Results of
studies into the precise nature of this relationship, however, have been
inconsistent.
To gain a clearer understanding of the depression-pain connection,
researchers affiliated with the University of Michigan and the University of
Cologne, Germany, focused on the underlying mechanisms in the perception of
pain, physical and emotional: the brain. Their findings, featured in the May
2005 issue of Arthritis & Rheumatism (
http://www.interscience.wiley.com/journal/arthritis),
challenge existing notions on the interplay of emotion and sensation and
have important implications for treating depression and pain as separate
conditions, even when they occur simultaneously.
The study focused on 53 patients, 33 women and 20 men, with
fibromyalgia (FM). This syndrome is
characterized by intense widespread pain and tenderness to touch and is
often accompanied by depression. Using this patient population, the
research team set out to evaluate whether higher levels of symptoms of
depression are associated with increased sensitivity to pressure-induced
pain, as well as to determine which regions of the brain are involved in
processing acute pain, chronic pain, and depressive symptoms. 42 healthy
controls, 20 women and 22 men, were also included in the study. The mean age
was 42 for the FM patients and 38 for the controls.
Conducted at Georgetown University's General Clinical Research Center,
the study began by assessing the severity of chronic pain and depression in
FM patients, through a combination of interviews, questionnaires, and
measurement scales. The following day, all subjects, both FM patients and
controls, participated in pressure-pain sensitivity experiments, involving
the application of pressure to a thumbnail. To get a clear picture of the
brain's response to painful stimuli, all subjects underwent magnetic
resonance imagining (MRI) scans, before, during, and after the
pressure-sensitivity sessions. FM patients were required to discontinue
antidepressant medications 4 weeks prior to the study, as well as refrain
from using any drugs for pain, including over-the-counter analgesics,
starting 3 days before the study.
Based on the MRI results, the researchers found that FM patients required
significantly less applied pressure than healthy controls to activate
neurons associated with acute pain in the brain's sensory domain. This
heightened sensitivity applied to FM patients in general, regardless of
whether they had been diagnosed with major depressive disorder or reported
any depressive symptoms. Furthermore, the researchers found only a weak
correlation between the sensory regions of the brain associated with chronic
pain and the affective or emotional regions of the brain associated with
depression.
“Much has been made of the overlap and similarities between pain and
symptoms of depression, but these and other data suggest it is also
important to identify pain-processing mechanisms that are independent of
mood,” notes the study's leading author, Thorsten Giesecke, M.D. “The notion
that sensory and affective aspects of pain may be independently processed is
not just of theoretical interest,” he adds. “Evaluation of these sensory and
affective dimensions in patients with chronic pain is likely to improve
diagnosis, choice of treatment, and treatment efficacy.” As this study
affirms, prescribing a standard antidepressant medication will not
necessarily relieve the suffering of a depressed patient whose pain is not
only real but also intensely physical. # # #
Article : “The Relationship Between
Depression, Clinical Pain, and Experimental Pain in a Chronic Pain Cohort,”
Thorsten Giesecke, Richard H. Gracely, David A. Williams, Michael E. Geisser,
Frank W. Petzke, and Daniel J. Clauw,
Arthritis & Rheumatism, May 2005; 52:5; pp. 1577-1584.
WHAT IS
FIBROMYALGIA?
Fibromyalgia is a disorder that causes muscle pain and
fatigue (feeling tired). People with fibromyalgia have "tender points" on
the body. Tender points are specific places on the neck, shoulders, back,
hips, arms, and legs. These points hurt when pressure is put on them.
People with fibromyalgia may also have other symptoms, such
as:
Trouble sleeping
Morning stiffness
Headaches
Painful menstrual
periods
Tingling or
numbness in hands and feet
Problems with thinking and memory
(sometimes called "fibro fog").
What Causes
Fibromyalgia?
The causes of fibromyalgia are unknown. There may be a
number of factors involved. Fibromyalgia has been linked to:
Stressful or
traumatic events, such as car accidents
Repetitive injuries
Illness
Certain diseases.
Fibromyalgia can also occur on its own.
Some scientists think that a gene or genes might be involved
in fibromyalgia. The genes could make a person react strongly to things that
other people would not find painful.
Who Is Affected by
Fibromyalgia?
Fibromyalgia affects as many as 1 in 50 Americans. Most
people with fibromyalgia are women. However, men and children also can have
the disorder. Most people are diagnosed during middle age.
People with certain other diseases may be more likely to
have fibromyalgia. These diseases include:
Rheumatoid
arthritis
Systemic lupus
erythematosus (commonly called lupus)
Ankylosing
spondylitis (spinal arthritis).
Women who have a family member with fibromyalgia may be more
likely to have fibromyalgia themselves.
How Is Fibromyalgia
Treated?
Fibromyalgia can be hard to treat. It's important to find a
doctor who is familiar with the disorder and its treatment. Many family
physicians, general internists, or rheumatologists can treat fibromyalgia.
Rheumatologists are doctors who specialize in arthritis and other conditions
that affect the joints or soft tissues.
Fibromyalgia treatment often requires a team approach. The
team may include your doctor, a physical therapist, and possibly other
health care providers. A pain or rheumatology clinic can be a good place to
get treatment.
The U.S. Food and Drug Administration (FDA) has not yet
approved any medicines to treat fibromyalgia. Doctors treat fibromyalgia
with medicines approved for other purposes. Pain medicines and
antidepressants are often used in treatment.
WHAT CAIN I DO TO TRY TO FEEL BETTER?
There are many things you can do to feel better, including:
Taking medicines as
prescribed
Getting enough
sleep
Exercising
Eating well
Making work changes if necessary.
WHAT
RESEARCH IS BEING DONE ON FIBROMYALGIA?
The NIAMS sponsors research to help understand fibromyalgia
and find better ways to diagnose, treat, and prevent it. Researchers are
studying:
Why people with
fibromyalgia have increased sensitivity to pain
The role of stress
hormones in the body
Medicines and
behavioral treatments
Whether there is a gene or genes that
make a person more likely to have fibromyalgia.
For More Information
on Fibromyalgia and Other Related Conditions:
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
National Institutes of Health
1 AMS Circle
Bethesda, MD 20892–3675
Phone: 301–495–4484 or 877–22–NIAMS (226–4267) (free of charge)
TTY: 301–565–2966
Fax: 301–718–6366
E-mail:
NIAMSInfo@mail.nih.gov
www.niams.nih.gov
SOURCE:
http://www.niams.nih.gov/hi/topics/fibromyalgia/fffibro.htm
