What is Depression?
Depression is one of the major emotional disorder resulting in behavioral and emotional sufferings. About 6.7 percent of the U.S. adults are treated for depression every year.1 Depression affects thought, mood, and conduct. Depression leads to isolation, inactivity, and drug dependence.
Does Chronic Pain Cause Depression?
People with chronic pain have three times the average risk of developing depression and anxiety (mood) disorder. Depression is one of the common psychiatric disease associated with chronic pain.1 Scientific study involving 243 rheumatoid arthritis patients suffering with chronic pain suggests depression was more common among these patients than average asymptomatic patients.2
Why Depression is Associated with Chronic Pain?
All chronic pain patients do not suffer with depression. Few chronic pain patients suffer with major or minor depression because of abnormal behavior of neurotransmitter. Neurotransmitters such as serotonin and nor-epinephrine are involved in transmission of pain and emotional impulses.3 Emotions and pain are regulated and modulated in limbic system. Cross communications may occur between pain and mood modulating impulses.
Is Neurotransmitter Abnormality a Common Illness?
No, neurotransmitter abnormality is not a common disease. Irregular activities of neurotransmitter such as norepinephrine, 5HT and serotonin are observed in depression, chronic pain, peripheral neuropathy, spinal cord injury, and cancer-induced bone pain. Similar changes are also seen in opioid-induced hyperalgesia.
Does Depression Intensify Chronic Pain?
Yes, several studies has suggested chronic pain patient suffer with higher pain intensity if depression is associated with pain. Muscular pain is extremely severe in fibromyalgia patients, even though muscle biopsy shows normal findings. Fibromyalgia is often associated with depression. Similarly chronic pain in cancer patient or non-cancer illness becomes severe if associated with depression.
What Are The Different Types of Depression?
There are several types of depression as described below.
- Major Depression
- Dysthymic Disorder
- Minor Depression
- Psychotic Depression
- Postpartum Depression
- Seasonal Affective Disorder
- Bipolar Disorder
Which Type of Depression is Associated with Chronic Pain?
Chronic pain is mostly associated with major depression.
What Are The Symptoms of Major Depression?
- Patients feels tired, irritable and restless.
- Mood abnormalities such as feeling of hopelessness, empty, guilty and worthlessness are also observed in patients with depression.
- Patients often indicate loss of interest in household activities, hobbies and sex.
- Patients do find difficulty with concentration, remembering, falling asleep or staying asleep (insomnia).
- Occasional serious symptoms such as thoughts of death and suicide are associated with suicidal attempt.
- Patients do suffer with fatigue and decreased energy.
- Few patients may show symptoms and signs of overeating, or appetite loss.
What is Bipolar Depression?
Bipolar depression is also a mood disorder. Bipolar depression is presented with symptoms of high (manic) and low (depression) mood changes. Symptoms during phase of manic or high mood changes are irritability, agitation, inflated self-esteem and inability to sleep. Symptoms during phase of depression or low mood changes are same symptoms as described in major depression.
What Are The Causes of Depression?
Causes of depression are as follows:
- Genetic Abnormalities - Often seen within several members of the family.
- Biological Abnormalities - Often associated with abnormalities in neurotransmission and limbic system of brain.
- Psychological Trauma - Caused by loss of a loved one, a difficult relationship, or any stressful situation may trigger a depressive episode.
Which Diagnostic Tests Are Used To Evaluate Depression?
Several tests are performed to rule out major medical illnesses and depression. Some of the liver and kidney illnesses may present similar symptoms as major depression. Electrolyte, kidney and liver disorder may influence brain function and present similar symptoms as major depression. Liver and kidney diseases may influence metabolism of antidepressant medications and may need adjustment of dosage.
1. Blood Examination:
- Liver Function.
- Kidney Function Test.
2. Radiological Studies:
- CT Scan.
- MRI of the brain is routinely performed to rule out brain tumor. MRI is also performed to investigate any specific abnormal findings, which may be associated with depression.
3. Electrocardiogram (ECG): ECG is performed to rule out heart diseases.
4. Electroencephalogram (EEG): EEG is performed to rule out brain diseases such as epilepsy and tumor.
5. Test of Depression Screening Instruments.
What Is The Depression Screening Instrument Test?
Several screening instruments or questionnaires have been studied in research and have been established as a useful tool to diagnose depression. Most common screening instruments consisting of several questions used in diagnosis of depression associated with chronic pain are as follows:
- Beck Depression Inventory (BDI) - This consist of 21 questions.
- Zung Self-Rating Depression Scale - Questions help diagnose severity of depression ranging from normal to severe.
- Hamilton Rating Scale for Depression (HRSD) - A multiple choice questions directed to diagnose severity of depression.
What Are The Specific Abnormal MRI Findings in Patients Suffering with Depression?
Magnetic resonance imaging (MRI) has shown that the MRI findings of the brain of people who have depression looks different than those without depression. Study performed by Lorenzetti V in 20094 has suggested MRI study can be diagnostic investigation, since MRI may show volumetric shrinkage of hippocampus and basal ganglia in-patient suffering with depression and chronic pain.
Who Is At Risk Of Developing Depression?
Females suffering with chronic pain are more likely to suffer with depression than male. Onset of depression in chronic pain patient is often seen during middle age.
Is Alcohol and Drug Addiction Common Among Patients Suffering with Depression and Chronic Pain?
Chronic pain patients are often treated with opioid pain medications. Opioid consumption for prolonged period may cause opioid dependence or addiction in patients suffering with chronic pain and depression. Alcohol and other substance abuse or dependence may also co-exist with depression.
What Are The Treatment Options for Depression Associated with Chronic Pain?
Depression associated with chronic pain is treated with medications, psychotherapy or both. Antidepressant Medications - Most of the antidepressant medications modulate the secretion of neurotransmitters serotonin, norepinephrine and dopamine. Antidepressants are classified in to 3 groups as follows:
- Selective Serotonin Reuptake Inhibitors also knows as SSRIs - Fluoxetine (Prozac), sertraline (Zoloft), escitalopram (Lexapro), paroxetine (Paxil), and citalopram (Celexa).
- Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) - Venlafaxine (Effexor) and duloxetine (Cymbalta).
- Dopaminergic Antidepressants - Bupropion (Wellbutrin).
What Are The Side Effects of These Antidepressants?
List of side effects caused by antidepressants are as follows:
Which Are The Other Antidepressants?
Tricyclics - imipramine and nor-triptyline.
Monoamine Oxidase Inhibitors (MAOIs).
What is Psychotherapy?
Psychotherapy treatment involves patient, family members and trained professional. Trained professional includes physician, psychologist, councilor or occupational therapy.
Psychotherapy involves the following treatments:
- Talk Therapy.
- Cognitive-Behavioral Therapy (CBT).
- Interpersonal Therapy (IPT).
Chronic Pain - Associated Depression: Antecedent or Consequence of Chronic Pain? A Review
Fishbain, David A. M.Sc., M.D., F.A.P.A.*†‡; Cutler, Robert Ph.D.*; Rosomoff, Hubert L. M.D., D.Med.Sc.†‡; Rosomoff, Renee Steele B.S.N., M.B.A., C.R.C., C.I.R.S., C.R.R.N.†
Clinical Journal of Pain:
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Brown, Gregory K.
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Preclinical and early clinical investigations related to monoaminergic pain modulation.
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Department of Neuroscience, Physiology and Pharmacology, Division of Bioscience, University College London, London WC1E 6BT, United Kingdom.
Structural brain abnormalities in major depressive disorder: a selective review of recent MRI studies.
Lorenzetti V, Allen NB, Fornito A, Yücel M.
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Melbourne Neuropsychiatry Centre, Department of Psychiatry, Australia.