What effects can mobile phones have on body tissues?

The potential effects of
mobile phone-associated electromagnetic radiation on tissues include "thermal"
and "non-thermal". Thermal effects are due to tissues being heated by rotations
of molecules induced by the electromagnetic field. In the case of a cell phone, the
head/ear surfaces close to the phone may be induced to heat. This heating has
been thought to cause molecules within cells called "heat-shock proteins" to
become activated and repeated activation of such proteins by
microwaves/electromagnetic radiation can lead to cellular events culminating in
cancerous transformation of the cell (C. Jolly & R.I. Morimoto, "Role of heatshock
response and molecular chaperones in oncogenesis and cell death";
Journal of the National Cancer Institute (2000) Volume 92; pages 1564-1761).
Non-thermal effects are due to low-frequency (but long-term) "pulsing" of the
carrier signal. Non-thermal effects from microwaves similar to those generated by
mobile phones have been implicated in genetic (DNA) molecule damage.

What is the Inverse Square Law and how is it relevant to mobile telephony?

The intensity of electromagnetic radiation varies with the distance from the source
according to the Inverse Square Law. This means that the radiation's intensity is
inversely proportional to the square of the distance between the source and the
exposed object. Applying this concept to mobile telephony, the further one holds
a mobile phone from the head, the less the (intensity) exposure of the head
and brain to electromagnetic radiation. This accounts for the relative safety of a
hands-free speaker phone mode and, in cars, the use of hands-free car
speaker/microphone kits (where the car's roof acts as the antenna) instead of
the mobile phone itself or an unshielded headset. Regarding car speaker kits for
hands-free mobile telephony, The Australian Government Environmental
Protection Agency states that due to the increased separation between the antenna
(now the car roof) and the user's head, exposure to electromagnetic radiation is
reduced by about 100 times when compared to normal mobile phone use.

What about "walkie-talkies" or "CB (Citizens' Band) radios"?

Unfortunately,
these devices emit at relatively very high power outputs (e.g., 3-4 W) compared
to mobile and cordless phones, even though their frequency bands may be lower.
They are considered to be the worst offenders of all the mainstream hand-held
"wireless" two-way communication devices in terms of electromagnetic radiation
exposure. They are widely used by our emergency services, armed forces,
construction sites, trucking industry airports and rural communities. Children use
them without any knowledge of the potential dangers associated with such
devices.

Addiction Is a 'Brain Disease'

Scientific advances have offered remarkable insights into how the human brain works and how it molds behaviors that affect drug addiction, say the directors of the National Institute on Drug Abuse (NIDA) and the National Institute on Alcohol Abuse and Alcoholism (NIAAA), National Institutes of Health, in a newly published article.

Building on these foundations, scientists can now investigate issues that were previously inaccessible, such as how environmental factors and genes affect how the brain responds to drugs of abuse to drive the process of addiction. The report, by NIDA Director Dr. Nora D. Volkow, and NIAAA Director Dr. Ting-Kai Li, is published in the December 2004 issue of Nature Reviews Neuroscience.

"Drug addiction is a brain disease," says Dr. Volkow. "Although initial drug use might be voluntary, once addiction develops this control is markedly disrupted. Imaging studies have shown specific abnormalities in the brains of some, but not all, addicted individuals. While scientific advancements in the understanding of addiction have occurred at unprecedented speed in recent years, unanswered questions remain that highlight the need for further research to better define the neurobiological processes involved in addiction."

Recent studies have increased our knowledge of how drugs affect gene expression and brain circuitry, and how these factors affect human behavior. They have shed new light on the relationship between drug abuse and mental illness, and the roles played by heredity, age, and other factors in increased vulnerability to addiction. New knowledge from future research, say Dr. Volkow and Dr. Li, will guide new strategies and change the way clinicians approach the prevention and treatment of addiction.

More Addiction Research Needed

Topics of future investigations will include:

• Studies that further explain the brain's circuitry involved in making addicted individuals more responsive to biochemical changes caused by drugs of abuse;

• Explorations that look more deeply into the genetic and environmental factors associated with addiction, as well as the relationship between addiction and co-occurring mental illness;

• Developing tailored preventive interventions that take socioeconomic, cultural, age, and gender characteristics into consideration;

• Investigating new and existing medications that show potential as therapeutic options; and

• Pairing cognitive-behavioral strategies with medications to treat the brain changes brought about by chronic drug exposure.

"These new methodologies will provide us with a greater understanding of drug addiction," the scientists say. "But, to effectively treat and prevent drug addiction, we need to remove the condition's social stigma and enhance the involvement of the medical community. We also need to boost the contributions of the pharmaceutical industry in developing new medications and encourage the participation of insurers."

Is depression a brain disease ?

A kuro5hin.org article on 'Demystifying depression' gives an excellent account of the experience of depression, but uncritically repeats some common assumptions about the condition - namely that it is a 'physical illness' caused by 'low serotonin'.

Despite the familiarity of these claims, both are problematic.

* * *

The article by an author entitled Name of Feather takes a comprehensive look at clinical depression, and vividly describes the experience at the heart of the author's malady. It is also abound with good advice, such as seeking the help of a competent well-informed professional early in an episode.

It also attempts to describe what causes depression but makes several points that are often repeated as facts, but have surprisingly little support, or are highly controversial in the scientific literature.

Depression as a physical disease

The author asks us to "forget purely psychological explanations of the illness", "clinical depression is a physical illness" and claims that dualism, the idea that mind and brain are separate entities, is responsible for this false view of mental illness.

On a pragmatic level however, clinical depression is defined as mental phenomena. The criteria used by psychiatrists for diagnosing a Major Depressive Episode lists 'depressed mood' or 'loss of interest or pleasure' as the core feature and the majority of the additional features are purely psychological in nature.

If we want to believe that depression is a purely 'physical disease', then we could in fact feel pushed into dualism. Perhaps thinking that depression affects the brain and somehow the separate mind reacts to this impairment of thinking or emotion to produce the conscious experience of depression.

More likely, the view that depression is purely a physical illness reflects a school of thought known as epiphenomenalism, which argues that the mind has no causal effect at all, and is just the subjective experience of our brain at work.

However, both of these theories are roundly rejected by the majority of contemporary neuroscientists, psychologists and philosophers.

The most common view is that mind and brain are exactly the same sort of thing, but described at different levels of explanation - a school of thought known as property dualism. In other words, the mind is changes in the physical structure of the brain, and changes in the physical structure of the brain are the mind.

To make an analogy, no-one would deny that the economic system exists in the physical world, but to try and explain unemployment in terms of atomic physics would be folly, as would trying to solve economic problems by using a particle accelerator. In a similar way, we can accept that the mind and brain are both based in the physical world, but explaining the mind, or mental illness, purely in physical terms, may not always be appropriate or useful.

In a recent article for the American Journal of Psychiatry psychiatrist Kenneth Kendler cautions against exactly these sort of simple 'physical' explanations for mental illness and argues that comprehensive explanations and treatment will have to involve both psychological and biological theories.

If the logic of this argument is not convincing enough, recent studies have shown that psychotherapy has a measurable influence on brain function, with the neuroscience of psychotherapy now becoming an exciting complement to the vast amount of research on the psychological effects of physical treatments.

Depression as an illness of 'low serotonin'

In Name of Feather's article, he or she suggests that depression is caused by exhausting levels of serotonin in the brain. Unfortunately, there is little support for this simple theory.

If depression is nothing more than low serotonin, drugs that specifically lower serotonin levels in the brain should lead to depression or at least low mood. Studies which have tried this in both healthy participants and depressed patients show remarkably little effect on mood, with a mild dysphoria being the only occasional effect.

Furthermore, drugs which increase serotonin levels in the brain typically do not start having an effect on mood for several weeks, despite affecting serotonin levels immediately.

It is likely that serotonin plays some role in mood, but in a recent article for Nature Reviews Neuroscience, neuroscientist Eero Castrén criticises the oversimplified view of depression, stating:

Over the last few decades, the view that depression is produced by a chemical imbalance in the brain has become widely accepted among scientists, clinicians and the public.

However, during the past decade, several observations indicated that there might be an alternative hypothesis to the chemical view of depression. This network hypothesis proposes that mood disorders reflect problems in information processing within particular neural networks in the brain and that antidepressant drugs and other treatments that alleviate depression function by gradually improving information processing within these networks

It is notable that Name of Feather does mention an information processing approach to understanding depression, although it is important to note that this theory is a more complex and nuanced explanation than a simple 'low serotonin' theory can support.

Should we be cautious of purely biological theories of mental illness?

One motivation sometimes given for stating that mental illness is a purely 'physical disease' is to draw parallels with physical ailments, to try and make mental illness less stigmatised. Nevertheless, some research has suggested that purely biological explanations might have the opposite effect.

One study asked groups of participants to give their views on a person describing their experiences of mental illness. In one group, participants were subsequently given a biological and genetic explanation of mental illness, in another, they were given a social and psychological explanation. The group given the biological explanation were much more likely to rate the person as dangerous and unpredictable. Other research has suggested that clinicians with a purely biological perspective are likely to rate patients as more disturbed than other clinicians.

So why do simplified theories - like the 'low serotonin' theory of depression, persist - despite overwhelming evidence to the contrary ?

One view is from noted psychiatrist and psychopharmacologist David Healy who has criticised drug companies for promoting simplified biological theories of mental illness that seem to imply the primacy of drug treatments while ignoring social and developmental factors, which are known to be important influences in the development of mental illness.

Focusing specifically on depression and the development of antidepressant medication in his book The Antidepressant Era, he argues that drug companies have spent as much time marketing diseases as treatments, and laments the influence of pharmaceutical companies on scientific understanding.

Healy's views are not without controversy and need more unpacking than is space for here, although perhaps we can forgive overworked clinicians for seeing the attraction of simple 'one sentence' explanations for mental distress, despite the obvious complexity of the issue.

Conclusion
It is clear from the scientific literature that a purely biological theory of mental illness is not sufficient to explain and treat the experience of mental distress. Furthermore, simplified theories, that argue, for example, that depression is 'caused by low serotonin' are lacking in support and best avoided.

Psychological factors are equally important as biological factors in both the treatment and understanding of mental distress. Denying one or the other will undoubtedly slow scientific progress and lead to further misunderstanding of ourselves and each other.

Brain Diseases

The brain is the control center of the body. It controls thoughts, memory, speech and movement. It regulates the function of many organs. When the brain is healthy, it works quickly and automatically. However, when problems occur, the results can be devastating.

Inflammation in the brain can lead to problems such as vision loss, weakness and paralysis. Loss of brain cells, which happens if you suffer a stroke, can affect your ability to think clearly. Brain tumors can also press on nerves and affect brain function. Some brain diseases are genetic. And we do not know what causes some brain diseases, such as Alzheimer's disease.

The symptoms of brain diseases vary widely depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines or physical therapy can correct the source of the problem or improve symptoms.

What is electromagnetic radiation?

The World Health Organisation (WHO)
defines electromagnetic fields on its Webpages dedicated to the concerns
regarding the increasing presence of this form of radiation. In essence, an
electromagnetic field is comprised of two components, one being an electric
field generated by differences in voltage and another being a magnetic field
generated by the flow of current. The field propagates at the speed of light
(300,000 kilometres per second or 186,000 miles per second) in waves of a
certain length that oscillate at a certain frequency (number of oscillations or
cycles per second). In the electromagnetic range, gamma rays given off by
radioactive materials, cosmic rays, and X-rays are all dangerous to humans and
other organisms because of the relatively high energy "quanta" (packets) they
carry (high frequency or short-wavelength waves). Such rays lead to "dangerous
radiation" (ionizing; i.e., with an ability to break bonds between molecules).
Mobile phone systems also act in the electromagnetic range (sometimes
referred to as "microwave" or "radiofrequency"), however, the frequency
(energy "quanta") of the longer-wavelength waves associated with this
technology is lower (and therefore safer to humans) and regarded as "nonionizing"