Tuesday, May 01, 2012

Of a nervous disposition? Here's another thing to worry about: You're more likely to get cancer  -- if you are a mouse

There is no doubt that stress has a variety of adverse health effects and and anxious persons could be defined as highly  stressed so the mouse results may indeed generalize

Nervy individuals may be more at risk of aggressive cancer, new research suggests.  Scientists found that anxious mice were worse affected by skin tumours than less fearful animals.

Stressed and worried humans could be susceptible in the same way, they believe.

Researchers in the U.S. first identified laboratory mice with nervous personalities that avoided the dark or open spaces.  The hairless animals were then exposed to ultra violet radiation at levels equivalent to those experienced by humans who spend too long in the sun.

After a few months, the mice developed skin tumours - as did a group of non-anxious mice.  The difference was that the nervy mice grew more tumours, and only they went on to develop invasive skin cancer.

Anxious mice had higher levels of regulatory T-cells, whose job is to dampen down overblown immune responses.  They also produced fewer of the chemical signals needed to fire up an immune attack on tumours.

Levels of the stress hormone corticosterone were also raised in the anxious mice. The research appears in the online journal Public Library of Science ONE.

Lead author Dr Firdaus Dhabhar, from Stanford University Medical Centre in California, said: 'Anxiety may be defined as increased sensitivity to physically existent, or non-existent but perceived or anticipated, stressors.

'Identifying a psychological trait right at the beginning - before any experimental manipulation - and seeing that it can be associated with increased tumours months later, and with biology that can begin to explain mechanisms, was a rewarding surprise.'

Further research now needs to be carried out on human patients, said Dr Dhabhar. He added: 'It's bad enough that cancer diagnosis and treatment generates stress and anxiety, but this study shows that anxiety and stress can accelerate cancer progression, thus perpetuating a vicious cycle.

'The goal is to ameliorate or eliminate the effects of anxiety and chronic stress, at least at the time of cancer diagnosis and during treatment.'

Chronic stress has already been linked to cancer and other problems. But the latest study is said to be the first to show a biological connection between having an anxious disposition and greater threat from cancer.

Dr Dhabhar now wants to see whether countering the effects of anxiety and stress can improve the effectiveness of cancer treatment.  Taking an anxiety medication such as valium for limited periods of time might be helpful, he said.

'Ultimately, we really want to harness the patient's mind and body while doing everything that medicine can from the outside to maximise treatment success,' said Dr Dhabhar.


Anti-depressants 'may do more harm than good'

As a short-term assist to help individuals over a difficult patch -- particularly where suicide seems threatened -- they are readily enough justifiable but long-term use is problematical  -- JR

Common anti-depressants could be doing patients more harm than good, according to researchers who examined the impact of the medications on the whole body.

A team from McMaster University examined previous patient studies into the effects of anti-depressants and determined that the benefits of most anti-depressants compare poorly to the risks, which include premature death in elderly patients.

'We need to be much more cautious about the widespread use of these drugs,' said study leader and evolutionary biologist Paul Andrews.

'It's important because millions of people are prescribed anti-depressants each year, and the conventional wisdom about these drugs is that they're safe and effective.'

Anti-depressants are designed to relieve the symptoms of depression by increasing the levels of serotonin in the brain, where it regulates mood.

The vast majority of serotonin that the body produces, though, is used for other purposes, including digestion, forming blood clots at wound sites, reproduction and development.

The researchers, whose study was published in the online journal Frontiers in Psychology, found that anti-depressants had negative health effects on all processes normally regulated by serotonin.

This included a higher risk of developmental problems in infants,  problems with sexual function, digestive problems and abnormal bleeding and stroke in the elderly.

The authors reviewed three recent studies showing that elderly anti-depressant users are more likely to die than non-users, even after taking other important variables into account. The higher death rates indicate that the overall effect of these drugs on the body is more harmful than beneficial.

'Serotonin is an ancient chemical. It's intimately regulating many different processes, and when you interfere with these things you can expect, from an evolutionary perspective, that it's going to cause some harm,' Andrews said.

Millions of people are prescribed anti-depressants every year, and while the conclusions may seem surprising, Andrews says much of the evidence has long been apparent and available.

'The thing that's been missing in the debates about anti-depressants is an overall assessment of all these negative effects relative to their potential beneficial effects,' he says.

'You've got a minimal benefit, a laundry list of negative effects – some small, some rare and some not so rare. The issue is: does the list of negative effects outweigh the minimal benefit?'

In June 2011, Andrews and his colleagues had questioned the effectiveness of anti-depressants even for relieving depression.

They found patients were nearly twice as likely to suffer relapse after going off their medications as their brains worked to re-establish equilibrium.

The team studied dozens of previous papers to compare depressed patients who used anti-depressants compared to those who used placebos.

The analysis, published in Frontiers of Psychology, suggested people who have not been taking any medication are at a 25 per cent risk of relapse, compared to 42 per cent or higher for those who have taken and gone off an anti-depressant.

'We found that the more these drugs affect serotonin and other neurotransmitters in your brain - and that's what they're supposed to do - the greater your risk of relapse once you stop taking them,' Andrews said.

'All these drugs do reduce symptoms, probably to some degree, in the short-term. The trick is what happens in the long term.

'Our results suggest that when you try to go off the drugs, depression will bounce back. This can leave people stuck in a cycle where they need to keep taking anti-depressants to prevent a return of symptoms.'

Rethink Mental Illness CEO Paul Jenkins told Mail Online:  'There is a place for medication, and for some people affected by mental illness it can be life-saving or can help them maintain a good quality of life.

'However, it can also impact on people’s physical health, so it is crucial that health professionals explain the potential side-effects so people can make an informed choice. It’s also vital that GPs take extra care in monitoring the physical health of people taking such medication.

'Too often, people with depression are fobbed off with medication alone.

'People with mild to moderate depression should always be offered talking therapies before medication and people with severe depression should always be offered talking therapies along with medication.

'Sadly, access to psychological therapies, although improving, is still nowhere near good enough, and people are waiting months or even years to get access to the treatment they need.'

Talking therapies can be useless.  Only Cognitive Therapy and Rational-Emotive Therapy are definitely helpful  -- but only with some patients


1 comment:

John A said...

Depression... It might help if the psych diagnostic manual distinguished between what this layman terms short-term situational depression (loss of relative or job) and long-term physical-causes depression. It does not, and the same treatment (meds and talking) is reccomended for both. Yes, the symptoms are very similar, but if a GP treated walking pneumonia the same as a regular cold...

I do not doubt that a depressive put on enhancers/suppressors would have trouble re-adhusting when the drugs are withdrawn, but I would suggest that the long-term depressibe would "successfilly" adjust to previous insufficient levels. Since psych guidelines make no distinction, I stronglt suspect neither did these researchers.