A canna’ change the laws of physics

Scotty, The Naked Time, stardate 1704.3, Episode 7

Light on Evidence

Posted by apgaylard on November 3, 2007

 I recently wrote about the BBC’s rash promotional video news item about Seasonal Affective Disorder (SAD) and Lightwave Stimulation (LWS) therapy.  It is clear from what the advocates of this approach have put into the public domain that this is a speculative, pseudoscientific, treatment.

I’ve decided to dig a little deeper into the evidence base for LWS.  This post is just a quick progress report.

First, money: the Sound Learning Centre (irony levels rising!) charge £ 400 for a child (20 sessions) and £ 500 for an adult (25 sessions).  Not massively expensive, but at £60 per hour a significant cost.

Given that this ‘therapy’ is sold as a commercial product, might it not be expected to have a reasonable evidence base?  Well, remembering that this is ‘CAMworld’ our expectations should be tempered by experience.

I sent in an enquiry asking for details of the evidence to support the use of LWS.  The Sound Learning Centre very obligingly sent me their Client Information Pack (2006).  It contains a brief ‘explanation’ of the therapy, an impressive looking chart explaining how it ‘works’ and a reading list referencing just two books:

Light: Medicine of the Future (1991) by Dr Jacob Liberman

Light Years Ahead: The Illustrated Guide to Full Spectrum and Colored Light in Mindbody Healing (1996) edited by Brian Breiling.

Not an auspicious start.  I was hoping to see decent trials reported in peer-reviewed, reputable journals.

Instead we have two books.  Books are fine for reviewing a body of established knowledge.  They are also important opportunities for authors to advocate for their own ideas. 

This latter role can be problematic.  On one level this is obviously fine:  why shouldn’t an author advocate his views in his own book?  However, if we are looking for a reliable guide we need balance.  We need evidence to be assessed and weighed critically, not cherry picked, for example.  When justifying a medical intervention this is especially important.

Now, I’ve not had the opportunity to look at these books in the depth required to comment much further.  I have a second-hand copy of Liberman’s book on they way and will suspend judgement until I have had time to digest its contents.

In the meantime I decided to trawl the ‘net and see if I could come up with any journal papers.  One of the aliases for LWS is Ocular Light Therapy.  A search of PubMed did turn up two journal papers on this topic, both by the same author.

They appear in the Australian Journal of Holistic Nursing.  Now, I find it hard to conceive of any other form of nursing.  Also, I’m sure someone will correct me if I’m wrong, but this doesn’t seem to be a very prestigious publication.  Anyway, here are the references.  (I have only been able to get hold of one abstract and one introduction; and those were in google’s cache!  If anyone would like to send me a copy please get in touch.)

Deppe A., “Ocular light therapy: a case study.” Aust. J. Holist. Nurs. 2000 Apr; 7(1):41

The first paper is a single case study. It is published as part of the Practitioners Forum.  The introduction says:

“… My own experience with coloured light effects began when I worked with stained glass and became aware of the way in which the coloured light affected my own mood states. Using Ocular Light Therapy, rapid therapeutic change has occurred in clients, and I have moved from initial scepticism to the firm conviction that the practice of coloured light therapy has the potential to become a major tool in psychotherapy. “

It is not a trial of the therapy.  The abstract, at least, contains no mention of SAD.

Deppe A., “Light relief: the case for ocular light therapy” Aust. J. Holist. Nurs. 1999 Oct; 6(2):42-4.

It is referred to as a “non-refereed occasional paper“.  Here is the abstract; it is basically a historical review of an ill-founded therapy.

“… The historical lineage of practitioners involved in the use of coloured light in therapy can be traced from the early Egyptians, who reputedly suspended dyed cloth over wall openings to bathe the patient in colour. Other renowned practitioners include Pythagoras, Goethe and Rudolph Steiner. Coloured light therapy is now being practised by many clinician/scientists, mainly optometrists, and also by psychologists, educationalists, general medical practitioners, psychiatrists and chiropractors.”

Nice to see appeals to authority and common practise woven together so economically!

So, the story so far:  you can pay £60 per hour too look at dim coloured lights.  The evidence that it will do you any good just does not seem to be there.  That’s also the conclusion reached in this useful short review, based on information from Natural Standard and the Faculty of the Harvard Medical School.  The site seems to be pretty pro-CAM.  Even so, considering the whole gamut of ‘colour therapies’ (including Ocular Light Therapy) they say:

“… Color therapy has been suggested for many conditions, but safety and effectiveness have not been thoroughly studied scientifically …”

They also note that it is suggested as a treatment for a very long list of conditions:

 “… based on tradition or on scientific theories. However, these uses have not been thoroughly studied in humans, and there is limited scientific evidence about safety or effectiveness. Some of these suggested uses are for conditions that are potentially life-threatening.”

A list is provided of “Unproven Uses“:

  • Aggressive or hostile behavior
  • Asthma
  • Attention-deficit hyperactivity disorder
  • Bronchitis
  • Dyslexia and other reading disabilities
  • Enhanced athletic performance
  • Enzyme stimulation
  • Epilepsy
  • High or low blood pressure
  • Improved academic performance and IQ
  • Increased strength Insomnia
  • Learning disabilities
  • Lethargy
  • Lung cancer
  • Migraine
  • Muscle relaxation
  • Prison reform
  • Seasonal affective disorder
  • Sedation
  • Stress
  • Tension
  • Uterine fibroids
  • Vision disorders

SAD’s on the list.


The list of references provided at the end of this review (No.11) does cite one paper on light treatment for SAD.  This is a study of bright (white) light therapy; it failed to beat a dim red light.

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