Ion therapy
Encyclopedia
Negative air ionization therapy is the use of air ioniser
s as an experimental non-pharmaceutical treatment for seasonal affective disorder
(SAD) and mild depression
.
For SAD, a randomized controlled trial
(RCT) comparing high (4.5x1014 ions/second) and low (1.7x1011 ions/second) flow rate negative air ionization with bright light therapy found that posttreatment improvement results were 57.1% for bright light (10,000 lux) compared with high-density ions, 47.9%; and low-density ions, 22.7%. An older RCT conducted by the same authors also found air ionization effective for SAD at 2.7x106 ions/cm3. A 2007 review considers this therapy "under investigation", and suggests that it may be a helpful treatment for SAD.
A RCT comparing the short-term effects of bright light, an auditory stimulus, and high- and low-density negative ions on mood and alertness in mildly depressed and non-depressed adults found that the three active stimuli, but not the low-density placebo, reduced depression on the Beck Depression Inventory
scale; the auditory stimulus, bright light and high-density ions all produced rapid mood changes—with small to medium effect size
s—in depressed and non-depressed subjects.
Michael Terman, professor of clinical psychology
in the Department of Psychiatry at Columbia University
, who conducted the two studies on SAD, suggests that the mechanism responsible for the effect of this therapy on SAD is that the negative ion machines used in his studies are designed to mimic summer-like conditions by supplementing the sparse winter ion supply. He stresses however that although some air purifiers utilize negative ion technology, the dose of ions delivered by a typical air purifier is far too low for it to have an antidepressant effect. As of 2009, the negative ion generators used are still undergoing multicenter phase II clinical trials.
A separate randomized placebo-controlled study published in May 2010, found that high-density ion therapy was more effective than placebo (dim red light and low-density ions) but that the results were not statistically significant. The conclusion of this study was that bright white light therapy was significantly more effective than negative ion therapy for treating Seasonal Affective Disorder (SAD).
Air ioniser
An air ioniser is a device that uses high voltage to ionise air molecules. Negative ions, or anions, are particles with one or more extra electrons, conferring a net negative charge to the particle. Cations are positive ions missing one or more electrons, resulting in a net positive charge...
s as an experimental non-pharmaceutical treatment for seasonal affective disorder
Seasonal affective disorder
Seasonal affective disorder , also known as winter depression, winter blues, summer depression, summer blues, or seasonal depression, is a mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or summer, spring or autumn...
(SAD) and mild depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
.
For SAD, a randomized controlled trial
Randomized controlled trial
A randomized controlled trial is a type of scientific experiment - a form of clinical trial - most commonly used in testing the safety and efficacy or effectiveness of healthcare services or health technologies A randomized controlled trial (RCT) is a type of scientific experiment - a form of...
(RCT) comparing high (4.5x1014 ions/second) and low (1.7x1011 ions/second) flow rate negative air ionization with bright light therapy found that posttreatment improvement results were 57.1% for bright light (10,000 lux) compared with high-density ions, 47.9%; and low-density ions, 22.7%. An older RCT conducted by the same authors also found air ionization effective for SAD at 2.7x106 ions/cm3. A 2007 review considers this therapy "under investigation", and suggests that it may be a helpful treatment for SAD.
A RCT comparing the short-term effects of bright light, an auditory stimulus, and high- and low-density negative ions on mood and alertness in mildly depressed and non-depressed adults found that the three active stimuli, but not the low-density placebo, reduced depression on the Beck Depression Inventory
Beck Depression Inventory
The Beck Depression Inventory , created by Dr. Aaron T. Beck, is a 21-question multiple-choice self-report inventory, one of the most widely used instruments for measuring the severity of depression...
scale; the auditory stimulus, bright light and high-density ions all produced rapid mood changes—with small to medium effect size
Effect size
In statistics, an effect size is a measure of the strength of the relationship between two variables in a statistical population, or a sample-based estimate of that quantity...
s—in depressed and non-depressed subjects.
Michael Terman, professor of clinical psychology
Clinical psychology
Clinical psychology is an integration of science, theory and clinical knowledge for the purpose of understanding, preventing, and relieving psychologically-based distress or dysfunction and to promote subjective well-being and personal development...
in the Department of Psychiatry at Columbia University
Columbia University
Columbia University in the City of New York is a private, Ivy League university in Manhattan, New York City. Columbia is the oldest institution of higher learning in the state of New York, the fifth oldest in the United States, and one of the country's nine Colonial Colleges founded before the...
, who conducted the two studies on SAD, suggests that the mechanism responsible for the effect of this therapy on SAD is that the negative ion machines used in his studies are designed to mimic summer-like conditions by supplementing the sparse winter ion supply. He stresses however that although some air purifiers utilize negative ion technology, the dose of ions delivered by a typical air purifier is far too low for it to have an antidepressant effect. As of 2009, the negative ion generators used are still undergoing multicenter phase II clinical trials.
A separate randomized placebo-controlled study published in May 2010, found that high-density ion therapy was more effective than placebo (dim red light and low-density ions) but that the results were not statistically significant. The conclusion of this study was that bright white light therapy was significantly more effective than negative ion therapy for treating Seasonal Affective Disorder (SAD).