Cannabis users 'born with smaller front part of brain' affecting memory and decision-making
As a before-and-after study this is pretty strong evidence. The biggest pot-head I have ever known always seemed to me to be pretty "out of it" whether he was "high" or not
Teenagers who smoke cannabis are likely to have been born with an area of the brain that is significantly smaller than normal, according to new research.
Scientists have found that the area at the front of the brain, known as the orbitofrontal cortex, which controls memory, reward and decision- making, is six per cent smaller in children who go on to smoke cannabis compared with those who do not.
This difference in size may mean the brain is not as effective, so children with a smaller orbitofrontal cortex could be more impulsive and less capable of carefully calculated decision-making. In turn, this could make them more likely to experiment with cannabis.
Previous research has found that adults who are heavy cannabis smokers have much smaller brain volumes in this area, but it had, until now, been assumed the damage was caused by the regular drug use.
However, the new findings suggest that some people are born with the abnormality. The discovery could serve as an early-warning system to help identify those most at risk of becoming addicts.
The research, carried out in Melbourne, Australia, and published in the journal Biological Psychiatry, was part of a wider four-year study into the emotional development of children.
Initially, scientists took detailed scans of the brains of 121 children aged 12 – before they had begun to experiment with alcohol, cigarettes and other drugs such as cannabis.
Once they turned 16, the teenagers were asked a series of questions, including whether they had smoked cannabis. Of the 28 who admitted to using it – 23 per cent of the group – most said they had smoked it fewer than ten times.
The researchers then studied the scans again to determine whether there was anything that linked the cannabis smokers.
They discovered that the average volume of the orbitofrontal cortex was six per cent smaller in the group who had used the drug. The results were the same even after adjustments for other factors, including psychiatric problems, alcohol consumption and cigarette smoking, had been made.
The research also appears to prove that cannabis is toxic. Other studies on long-term users have found that the drug seems to affect the size of other areas of the brain. But as the scans showed these to be normal in children who had smoked the drug, this would suggest that it is regular, heavy cannabis use that is causing the damage.
According to the British Crime Survey, more than a third of 16- to 24-year-olds used it during 2009/10.
Try to stay positive .... it’s become a common call to those who are ill as the belief has grown that having a positive attitude will not only help you get through illness, but make you better quicker.
But is it true? In fact, there’s no evidence that teaching yourself to have a positive attitude makes you physically healthier. A recent study of cancer patients in Finland and Sweden found no association between survival rates and whether people were positive or negative in their outlook.
The study, in the American Journal Of Epidemiology, looked at 4,600 people with cancer over 30 years, and found that whether they were extrovert or neurotic, their attitude to life had no relationship with how long they survived their illness.
It’s not an isolated finding. An analysis of research by Dr James Coyne, professor of psychology at the University of Pennsylvania School of Medicine, found that there were no good quality studies showing that ‘positive psychology’ had any effect on physical health. In one of his own large studies, he found that the sense of emotional wellbeing of cancer patients had no effect on how long they lived.
Yet self-help gurus such as Louise Hay, whose book You Can Heal Your Life has sold 35 million copies worldwide over the past 20 years, says that ‘science is now confirming that we can’t allow ourselves to indulge in negative thinking. It’s making us sick and it’s killing us’.
British researchers and health staff are becoming concerned that American lifestyle gurus who urge us to ‘be positive and live longer’ may be doing more harm than good.
Claire Murrell, head of nursing at the Barts and the London Hospital Cancer Unit, is concerned that too many people are being urged to ‘be positive’ after a cancer diagnosis, when they need to be realistic and realise they will experience emotional lows.
‘I think that some people with cancer do come down with a bump when they realise that, for all their positive attitude, they haven’t been cured,’ she says. ‘I’ve come across people who feel a lot of pressure to be positive, sometimes from family and friends, at a time when they really don’t want to.’
Her words echo those of film star Michael Douglas, who last year spoke of his concern for his wife Catherine Zeta-Jones when she was reported to have mental health problems. He said she broke down under the stress of his battle with throat cancer because she tried to put on a brave, positive face all the time. He may have been right.
As one patient recently wrote on an internet forum for cancer patients: ‘Keeping up with the positive thinking is very hard, particularly in front of friends and family. Sometimes I just feel like screaming at the world. ‘For me, remaining positive is sometimes harder than dealing with the chemo side effects and having cancer.’
Things can be even harder if you expect positive thoughts to make you better. In her book Smile Or Die: How Positive Thinking Fooled America And the World, Barbara Ehrenreich quotes a woman who had been following the healing advice of mind-body guru Deepak Chopra.
The woman wrote to Chopra: ‘Even though I follow the treatments, have come a long way in unburdening myself of toxic feelings, have forgiven everyone, changed my lifestyle to include meditation, prayer, proper diet, exercise and supplements, the cancer keeps coming back. Am I missing a lesson here that it keeps reoccurring?’
The problem is research findings are diverse and complex, so the science is ambiguous enough to allow lifestyle gurus scope for claiming it backs their teachings. There are studies indicating that people with a positive attitude cope better with illness — even if they don’t get better quicker. Indeed, relaxation and emotional support are extremely important in helping people with life-threatening illness get on with life.
And how stressed people are (as opposed to how positive) does seem to predict how some conditions such as heart disease progress — stress affects the body’s immune and hormone systems.
There are also some studies suggesting that people who are born with, or develop early in life, an ability to dwell on what can be done, rather than what can’t, may be healthier.
Research on 1,000 people attending the famous Mayo Clinic in the U.S. over 30 years found that those classified as optimists had a 19 per cent higher chance of still being alive than pessimists.
But this is all different from saying that taking a positive attitude makes you healthier.
Dr Gerard Molloy, chair of the UK Society For Behavioural Medicine’s scientific committee, says that though psychological traits such as optimism may be linked to longer survival from illness, there is no evidence that such traits can be cultivated by ‘positive thinking’. You’re either like that or you’re not.
‘Some of the strongest evidence revolves around personality types,’ says Dr Molloy, who is lecturer at the Centre for Health and Behaviour Change at the University of Stirling.
‘But personality type is, by definition, impossible to change. I think the idea of adopting a positive psychology has come over from the U.S., where there’s a “Yes we can” culture, and the wellness thing is hanging on to the coat-tails of that.’ Our desire that positive thinking should improve health gets in the way of the facts, he believes.
Dr Gill Windle, a research fellow at the University of Bangor, agrees. She recently saw one of her studies reported under the headline: ‘Positive attitude can help you drive away illness.’ In fact, her study of nearly 2,000 older people concluded something different. It found that those with ‘resilient personalities’ didn’t let their symptoms get to them as much, but they weren’t actually any less ill. ‘The research isn’t there yet to say whether they are actually physically better,’ says Windle.
Resilience is the ability to recover easily from misfortune or change. Unlike a positive personality, it is something that can be encouraged and developed.
So even if we can’t make ourselves better in the face of illness, we can feel better. This in itself has value, and the key may be other people’s attitudes, not our own.
‘Resilience isn’t always about an innate capacity, it’s also about becoming strong because of the support you receive,’ says Windle. ‘Emotional support or not having to battle for services can make you resilient and cope with adversity much better.’
In other words, those family and friends who urge us to ‘keep positive’ might help us cope with illness better if they helped us free up our time and energy to feel exactly what we want to feel.