Posted by Anna laura on November 20, 2001, at 2:33:45
In reply to What meds for SAD?, posted by Hattree on November 19, 2001, at 14:57:40
> Anything supposed to be particularly good for seasonal depression?
Here are some excerpts from some reasearch i've made:
"The symptoms for SAD are much like those of depression, and can include lethargy, altered appetite, sleepiness, feelings of despair, and poor attention span. It can adversely affect one's relationships at home and at work. Women seem especially prone: 75 to 80 percent of SAD sufferers are women, according to Paul Shield, M.D., an expert in the field whose taped lecture is available through the Self-Help Center in Psychological Services in Rhode Island Hall.SAD is caused by light deprivation, thus the treatment involves light therapy. The good news is that the effects of treatment can usually be seen in a few days of bright-light sessions. Each session can last from 30 minutes to two hours.
Treatment is based on the interaction of light with the eyes, not with the skin, says Shield. A light box of 2500 watts seems to be effective for most people, he says. A light box costs from $300 to $500 - some insurers reimburse clients for light therapy boxes. A portable alternative is a visor worn directly above the eyes. Light therapy is not recommended for people who have photosensitive skin or are taking drugs that increase light sensitivity, or for those who have had eye surgery. Any light therapy should be done only under the guidance of a health professional.
"The light needs to be intense to be effective, but the full spectrum is not necessary," says Shield. "Ordinary fluorescent light bulbs or halogen lamps are satisfactory. One shouldn't use heat lamps or UV light; they're unhealthy." Looking at the light is the key - a quick glance every few minutes during the session is necessary for the treatment to work.
Those who respond to light therapy may notice that their moods improved as soon as two to four days into the course of treatment. "If there's little or no response after a week, it's most likely not SAD," he says. For some people a combination of drug treatment and light therapy may be effective.
SAD not only occurs with the onset of winter, but can affect some people in the hot months of summer, according to Shield. "It's called Summer Seasonal Affective Disorder. Heat makes some people instantly depressed. They respond better to cold. For them, cold showers, air-conditioning and even anti-depressants seem to work."
The science behind SAD involves the regulation of the neurotransmitter serotonin and the hormone melatonin. The latter is secreted at night by the pineal gland, a pea-sized structure at the base of the brain. Melatonin appears to play a major role in regulating the body's circadian rhythms, says Shield. Melatonin also appears to decrease serotonin levels. "It probably takes two weeks of insufficient light to significantly decrease serotonin, which leads to depression," he says. Popular anti-depressant medications that target serotonin seem to work because they increase serotonin concentration at synapses in the central nervous system.
Basically, bright morning light "resets" the body's clock. Interestingly, in blind people, their circadian rhythms "free wheel," according to Shield, and become asynchronous to a 24-hour day. "If left to free wheel, people's natural biological clocks correlate inversely to their age," he adds. Young people have a biological day of about 25 to 26 hours; middle-agers are about 24 hours; and the elderly tend to run less than 24 hours.
Sources on S.A.D.
* "Seasonal Affective Disorder," audiotape of session by Paul Shield, M.D., March 3, 1994, available at Psychological Services in Rhode Island Hall.
* Winter Blues: Seasonal Affective Disorder: What It Is and How to Overcome It (New York: Guilford, 1993) by Norman E. Rosenthal, M.D., chief of the unit of outpatient studies and staff psychiatrist at the National Institutes of Mental Health, Washington, D.C.
* National Institutes of Mental Health: 301-496-2141.
* Harvard's Women's Health Watch, 164 Longwood Ave., Boston, Mass., 02115Melatonin and Depressive Disorders
Much has been written about Melatonin, Seasonal Affective Disorder and Endogenous Depression.Webb and Puig-Domingo have reviewed the literature and I quote from their article.(1)
"Seasonal Affective Disorder (SAD) a depression occurring in the Winter months and associated with hypersomnia,weight gain and craving for carbohydrate has been found to improve with bright light treatment (Rosenthal et al., 1984) The benefit appeared to be related to light rather than Melatonin inhibition as these workers found that pharmacological suppression of Melatonin did not improve their depression."
Changes in magnetic fields alter Melatonin secretion and affect circadian rhythms. Environmental magnetic fields (MF) have diminished strength during the Winter months and there may be desynchronisation of circadian rhythm.Both acute exposure to light and exposure to MF suppress Melatonin secretion and may be beneficial for patient's with Winter depression. It has been proposed that the synergistic effect of light and magnetic therapy in these patients may be superior to phototherapy alone.(14) Low Melatonin levels have been observed in depressed subjects, (McIntyre et al., 1986) unipolar or bipolar Affective Disorders (Beck-Friis et al.,1985) and chronic schizophrenia (Ferrier et al., 1982). Low nocturnal Melatonin has been proposed as a trait marker for major depressive disorders by Beck-Friis et al.,1985 (1) Therapy with monoamine oxidase inhibitors (MAO) increases pineal content of serotonin (Melatonin precursor),Tricyclic antidepressants reduce Melatonin production and secretion in rodents (Lewis et al., 1990) Other psychotropic drugs which interfere with monoamine pathways also affect pineal mel. Melatonin has been proposed to inhibit CRH(corticotrophin release hormone) during major depression.(1) Receptors for Benzodiazepines have been reported to exist in the pineal gland of several animal species (Lowenstein et al., 1984) In humans Alprazolam given before lights out suppressed nocturnal Melatonin and cortisol.(1) Many environmental and endogenous factors can potentially affect Melatonin secretion and thus a definite therapeutic relationship between mel and psychiatric disorders remains unproven.(1) The conventional view that the underlying abnormality in endogenous depression is due to an abnormality in the body clock has been challenged. (Healy D., Waterhouse JM, Pharm and Therapeutics 65 (2):241-63,1995 Feb). They suggest that the circadian system in endogenous depression resembles its state in healthy individuals after time-zone transitions or in shift work maladaptation syndrome and disturbances result from changes in the phasing of external time givers(zeitgebers) rather than from an abnormality in the clock itself.
poster:Anna laura
thread:84677
URL: http://www.dr-bob.org/babble/20011113/msgs/84737.html