June 28 - 29, 2007 Advisory Committee Meeting
Dr. Dishman was asked to discuss issues the Committee should be aware of
concerning mental health.
Mental health problems are prevalent, costly, contribute to disability and
reduced quality of life. Many studies address this but they are not uniform in
quality and quantity across population sub-segments. Most of the data is recent
so problems interpreting earlier data versus recent data may not be as
problematic in mental health.
Methodological issues to consider from observational studies include the fact
that a large portion of the data comes from archival studies not designed to
directly test the relations of mental health and physical activity. There is
also concern across age groups pertaining to the use of questionnaires for the
mental health variables that are really measures of symptoms that may have
differing relative importance depending on age groups. Additionally, there are
no studies looking at the impact of reducing symptoms in healthy folks for
preventing subsequent diagnosis as well as virtually no evidence on the impact
of reducing symptoms in diagnosed folks or reducing the risk of secondary
Some excluded topics to reconsider and/or flag for Phase B include childhood
cognitive function literature and studies on physical activity in an acute
setting on mental health or mood.
Discussion among the Committee included the relationship of acute effects and
behavioral issues. For example, a behavioral barrier to exercise is the
perception an individual needs to wait to receive a benefit while the benefit is
more of a series of repeated acute effects.
Subsequent comments from the Committee centered on exposures that will reduce
the level of a certain trait or something in a person that hasn't reached a
disease level yet. The data should be portrayed in the proper context that we do
not have the evidence and that indeed the reduction symptoms in arbitrarily
defined healthy folks have not yet been shown to reduce the incidents of the
arbitrarily defined diagnosis.
A question was asked regarding where Alzheimer's and multi-infarct dementia
as well as mind/body exercise types such as Tai Chi fit. While there may not be
sufficient data available linked to mental health anything that can help inform
their benefit should be included.
Regarding repeated acute effects versus chronic adaptations and the
relationship of enjoyment there is loose terminology used by investigators
leading to serious interpretation issues. Similarly, fatigue is another area in
cancer survivors where there is substantial evidence from randomized control
trials that physical activity reduces subjective feelings of fatigue; however, a
challenge in this area is that much of the data is from self-report