What cannabis actually does to your brain

Archaeologists recently found a 2,700-year-old pot stash, so we know humans have been smoking weed for thousands of years. But it was only about 20 years ago that neuroscientists began to understand how it affects our brains.

Scientists have known for a while that the active ingredient in cannabis was a chemical called delta-9-tetrahydrocannabinol, or THC for short. Ingesting or smoking THC has a wide range of effects, from the psychoactive "getting high" to the physiological relief of pain and swelling. It also acts as both a stimulant and depressant. How could one substance do all that?

Meet the cannabinoid receptor

In the 1980s and 90s, researchers identified cannabinoid receptors, long, ropy proteins that weave themselves into the surfaces of our cells and process THC. They also process other chemicals, many of them naturally occurring in our bodies. Once we'd discovered these receptors, we knew exactly where THC was being processed in our bodies and brains, as well as what physical systems it was affecting. Scattered throughout the body, cannabinoid receptors come in two varieties, called CB1 and CB2 - most of your CB1 receptors are in your brain, and are responsible for that "high" feeling when you smoke pot. CB2 receptors, often associated with the immune system, are found all over the body. THC interacts with both, which is why the drug gives you the giggles and also (when interacting with the immune system) reduces swelling and pain.

 

Cannabinoid receptors evolved in sea squirts about 500 million years ago; humans and many other creatures inherited ours from a distant ancestor we share with these simple sea creatures. THC binds to receptors in animals as well as humans, with similar effects.

Tasty, tasty, tasty

Cannabis notoriously makes people hungry - even cancer patients who had lost all desire to eat.One study showed that cancer patients who thought food smelled and tasted awful suddenly regained an ability to appreciate food odors after ingesting a THC compound. There are CB1 receptors in your hypothalamus, a part of your brain known to regulate appetite, and your body's own cannabinoids usually send the "I'm hungry" message to them. But when you ingest THC, you artificially boost the amount of cannabinoids sending that message to your hypothalamus, which is why you get the munchies.

Understanding this process has actually led to a new body of research into safe diet drugs that would block those cannabinoid receptors. That way, your hypothalamus wouldn't receive signals from your body telling it to eat, and would reduce hunger cravings in dieters.

What you're forgetting

What's happening in your brain when smoking pot makes you forget what you're saying in the middle of saying it? According to the book Marijuana and Medicine (National Academies Press):

One of the primary effects of marijuana in humans is disruption of short-term memory. That is consistent with the abundance of CB1 receptors in the hippocampus, the brain region most closely associated with memory. The effects of THC resemble a temporary hippocampal lesion.

That's right - smoking a joint creates the effect of temporary brain damage.

What happens is that THC shuts down a lot of the normal neuroprocessing that goes on in your hippocampus, slowing down the memory process. So memories while stoned are often jumpy, as if parts are missing. That's because parts literally are missing: Basically you are saving a lot less information to your memory. It's not that you've quickly forgotten what's happened. You never remembered it at all.

A bit of the old timey wimey

Cannabis also distorts your sense of time. THC affects your brain's dopamine system, creating a stimulant effect. People who are stoned often report feeling excited, anxious, or energetic as a result. Like other stimulants, this affects people's sense of time. Things seem to pass quickly because the brain's clock is sped up. At the same time, as we discussed earlier (if you can remember), the drug slows down your ability to remember things. That's because it interferes with the brain's acetylcholine system, which is part of what helps you store those memories in your hippocampus. You can see that system's pathway through the brain in red in the illustration at left.

In an article io9 published last year about the neuroscience of time, we noted:

The interesting thing about smoking pot is that marijuana is one of those rare drugs that seems to interact with both the dopamine and the acetylcholine system, speeding up the former and slowing down the latter. That's why when you get stoned, your heart races but your memory sucks.

It's almost as if time is speeding up and slowing down at the same time.

Addiction and medicine

Some experts call cannabis a public health menace that's addictive and destroys lives by robbing people of ambition. Other experts call it a cure for everything from insomnia to glaucoma, and advocate its use as a medicine. The former want it to be illegal; the latter want it prescribed by doctors. Still other groups think it should be treated like other intoxicants such as alcohol and coffee - bad if you become dependent on it, but useful and just plain fun in other situations.

What's the truth? Scientists have proven that cannabis does have medical usefulness, and the more we learn the more intriguing these discoveries become. Since the early 1980s, medical researchers have published about how cannabis relieves pressure in the eye, thus easing the symptoms of glaucoma, a disease that causes blindness. THC is also "neuroprotective," meaning in essence that it prevents brain damage. Some studies have suggested that cannabis could mitigate the effects of Alzheimer's for this reason.

At the same time, we know that THC interferes with memory, and it's still uncertain what kinds of long-term effects the drug could have on memory functioning. No one has been able to prove definitively that it does or does not erode memory strength over time. Obviously, smoking it could cause lung damage. And, like the legal intoxicant alcohol, cannabis can become addictive.

Should cannabis be illegal, while alcohol flows? Unfortunately that's not the kind of question that science can answer. Let's leave the moral questions to courts, policymakers and shamans. I'll be off to the side, smoking a joint, thinking about my acetylcholine system and the many uses of the hippocampus.

British terror supergrass sentence cut by two years

jailed British terrorist has had his sentence cut by two years in a supergrass deal after giving evidence about an al Qaeda-linked “martyrdom” plot in New York, it was revealed today. Former teacher Saajid Badat was jailed for 13 years in 2005 for plotting with shoe bomber Richard Reid to blow up a transatlantic airliner in 2001 in what an Old Bailey judge said was a “wicked and inhuman” plot. He has now had his term reduced by two years under the first “supergrass” deal involving a terror convict, after providing intelligence to US prosecutors investigating an alleged plot to blow up the New York subway on the eighth anniversary of the 9/11 attack. Details of the deal — kept secret for more than two years — were revealed today by the Crown Prosecution Service as a trial of the alleged al Qaeda plotters began in New York. Defendant Adis Medanjanin, a 27-year-old Bosnian-born US citizen, is charged with conspiring to use a weapon of mass destruction, conspiring to commit murder in a foreign country, and providing “material support” to al Qaeda. He is said to have had terrorist training in Pakistan in 2008 and then returned to begin a plot to use beauty parlour chemicals to blow up the subway. Badat, from Gloucester, joined Reid’s shoe bomb conspiracy but pulled out at the last minute.

Western embassies targeted in Afghanistan attacks

 

Gunmen have launched multiple attacks across the Afghan capital Kabul. Western embassies in the heavily-guarded, central diplomatic area are understood to be among the targets as well as the parliament building in the west. There are reports that up to seven different locations have been hit. The Taliban has admitted responsibility, saying their main targets were the British and German embassies. There is no word at this stage on any casualties.

Taliban free hundreds from Pakistan prison

Hundreds of prisoners are believed to have escaped from a jail in northwest Pakistan after it was attacked by anti-government fighters armed with guns and rocket-propelled grenades. Some of those who escaped from the facility in the town of Bannu, in the Khyber Pakhtunkhwa province, early on Sunday morning were "militants", an intelligence official told the Reuters news agency. "Dozens of militants attacked Bannu's Central Jail in the early hours of the morning, and more 300 prisoners have escaped," Mir Sahib Jan, the official, said. In Depth   Profile: Pakistani Taliban "There was intense gunfire, and rocket-propelled grenades were also used." Many of those who escaped following the raid were convicted Tehreek-e-Taliban Pakistan (TTP) fighters, Al Jazeera's Kamal Hyder reported from Lahore. A prison official in Bannu confirmed that "384 prisoners have escaped". A police official identified one of the inmates who escaped as a "dangerous prisoner", who took part in one of the attempts to kill the former president, Pervez Musharraf. The TTP, an umbrella organisation for anti-government groups that are loosely allied with the Taliban in Afghanistan and al-Qaeda, took responsibility for the attack. A spokesman for Hakeemullah Mehsud, TTP's leader, confirmed to Al Jazeera that the group was responsible for the attack. Another Taliban spokesman told Reuters: "We have freed hundreds of our comrades in Bannu in this attack. Several of our people have reached their destinations, others are on their way.".   Our correspondent said the attack took place in the early morning and had resulted in an exchange of fire that had left several people wounded. "After the attack the paramilitary and regular military forces came to that location and tried to surround the area," he said. "They have arrested up to a dozen men, but most of the people have indeed escaped." The injured were rushed to a local hospital in Bannu. Sources told Al Jazeera that as many as 150 fighters were involved in the attack. After blowing up the gates of the main prison at around 1:30am local time (20:30 GMT on Saturday), they entered the compound and freed the inmates, the sources said. The attackers had arranged for the transportation of the inmates from the facility. A police official told Reuters that Bannu's Central Jail held 944 prisoners in total, and that six cell blocks had been targeted in the attack.

Addictive painkiller sales surge in new parts of U.S.

Sales of the two most popular prescription painkillers in the United States have exploded in new parts of the country, an Associated Press analysis shows, worrying experts who say the push to relieve patients' suffering is spawning an addiction epidemic. Drug Enforcement Administration figures show dramatic rises between 2000 and 2010 in the distribution of oxycodone, the key ingredient in OxyContin, Percocet and Percodan. Some places saw sales increase sixteenfold. Meanwhile, the distribution of hydrocodone, the key ingredient in Vicodin, Norco and Lortab, is rising in Appalachia, the original epicenter of the U.S. painkiller epidemic, as well as in the Midwest. The increases have coincided with a wave of overdose deaths, pharmacy robberies and other problems in New Mexico, Nevada, Utah, Florida and other states. Opioid pain relievers, the category that includes oxycodone and hydrocodone, caused 14,800 overdose deaths in 2008 alone, and the death toll is rising, the Centers for Disease Control and Prevention says. Across the U.S., pharmacies received and ultimately dispensed the equivalent of 69 tons of pure oxycodone and 42 tons of pure hydrocodone in 2010, the last year for which statistics are available. That's enough to give 40 5-mg Percocets and 24 5-mg Vicodins to every person in the United States. The DEA data records shipments from distributors to pharmacies, hospitals, practitioners and teaching institutions. The drugs are eventually dispensed and sold to patients, but the DEA does not keep track of how much individual patients receive. The increase is partly due to the aging U.S. population with pain issues and a greater willingness by doctors to treat pain, said Gregory Bunt, medical director at New York's Daytop Village chain of drug treatment clinics. Sales are also being driven by addiction, as users become physically dependent on painkillers and begin "doctor shopping" to keep the prescriptions coming, he said. "Prescription medications can provide enormous health and quality-of-life benefits to patients," Gil Kerlikowske, the U.S. drug czar, told Congress in March. "However, we all now recognize that these drugs can be just as dangerous and deadly as illicit substances when misused or abused." Opioids like hydrocodone and oxycodone can release intense feelings of well-being. Some abusers swallow the pills; others crush them, then smoke, snort or inject the powder. Unlike most street drugs, the problem has its roots in two disparate parts of the country -- Appalachia and affluent suburbs, said Pete Jackson, president of Advocates for the Reform of Prescription Opioids. "Now it's spreading from those two poles," Jackson said. A few areas that include military bases or Veterans Affairs hospitals have seen large increases in painkiller use because of soldier patients injured in the Middle East, law enforcement officials say. Experts worry painkiller sales are spreading quickly in areas where there are few clinics to treat people who get hooked, Bunt said. In Utica, New York, Patricia Reynolds has struggled to find treatment after becoming dependent on hydrocodone pills originally prescribed for a broken tailbone. The nearest clinics offering Suboxone, an anti-addiction drug, are an hour's drive away in Cooperstown or Syracuse. And those programs are full and are not accepting new patients, she said. "You can't have one clinic like that in the whole area," Reynolds said. "It's a really sad epidemic. I want people to start talking about it instead of pretending it's not a problem and hiding."

New info about statin safety affects millions

U.S. Food and Drug Administration issued new safety information about these cholesterol-lowering drugs that are prescribed to millions of Americans to lower the risk of heart disease. If you're among them, you should understand what the FDA's new guidance means for your health. "Before anyone gets too concerned, you should know that statins are so widely used because they have a long track record of safety and effectiveness," says Dr. Mark Taber, a cardiologist with SSM Heart Institute at St. Joseph Health Center. "All in all, statins have a very high benefit to risk ratio. The widespread use of the drugs, when indicated, probably accounts to a significant degree for the improvement in life expectancy in this country." The FDA called attention to the threat of liver damage as a rare side effect of statins and advised that regular liver enzyme testing is no longer considered useful in predicting or preventing liver injury. "Actually, in general they liberalized the follow up needed for liver function tests on patients taking statins, due to the very low incidence of true liver issues," Taber says. The main warnings related to a slightly higher incidence of developing diabetes while on statins, and a poorly substantiated claim that statins could result in cognitive impairment. Taber points out that cognitive problems, such as confusion or memory problems, were not documented in clinical studies, only by patient reports to the FDA website. "By stating these concerns, the FDA is raising awareness about the potential side effects of statins, but cardiologists already know that there are inherent risks, and we monitor patients appropriately to help ensure that side effects do not occur or are dealt with quickly," Taber notes. "If there is any evidence of a side effect that could be problematic, we can change the medication. But the fact remains that it's important to decrease risk of heart disease, and for many people statins are needed when diet and exercise alone don't result in acceptable cholesterol levels." Whenever a new prescription medication is started, you should look over the package insert to learn about potential side effects. Signs of liver damage, for instance, include fatigue, loss of appetite, right upper abdominal pain, dark urine and jaundice. Any of these symptoms should be reported to your doctor for evaluation. It is important to remember that you should not stop taking a medication without consulting your doctor first. Discontinuing use of a prescribed drug can be far more dangerous than the side effect you're worried about. "All the side effects listed by the FDA are rare, and the risk of heart attack is far more concerning," Taber says. "Some patients may need extra monitoring or may need to try more than one statin before we find the optimal choice, but in general statins are very well tolerated and don't cause problems for the people who take them." The advice above is universal when it comes to your health. Concerns should be discussed with your doctor, and decisions should always be made as part of a team approach to creating a healthy life.

Why don't GPS warn you that statins can harm your memory?

John Holliday had been on a higher 40mg dose of cholesterol pills for only a few weeks when he started to lose his concentration. ‘I’d be watching TV and suddenly find myself unable to follow the plot of a drama,’ says John, 52, a telecoms project manager who lives in Southend-on-Sea, Essex, with his wife Jill, 51, and their two children Adam, 20, and Emma, 16. ‘I’d have to read the same page of a book over and over because I couldn’t take any information in. ‘I’d always been known for my amazing memory — I was great on trivia and had total recall of events that happened 20 years ago, but suddenly I couldn’t remember things and my brain felt fuzzy.’ Just like up to seven million other people in Britain, John had been prescribed a statin to lower his blood cholesterol levels. The drugs are credited by the British Heart Foundation as contributing towards the dramatic 50 per cent fall in deaths from heart attacks in the past ten years. But while there is consensus that statins are lifesavers for people who have previously had a heart attack, concern is growing over their debilitating side-effects. They include muscle weakness, depression, sleep disturbance, sexual dysfunction, muscle pain and damage, gastro-intestinal problems, headaches, joint pains and nausea. Now, official bodies here and in the U.S. have ordered that the drugs must carry warnings for cognitive problems, too. Worryingly, it’s claimed GPs are failing to warn patients of the effect statins can have on the mind — meaning they may mistake them for signs of ageing or Alzheimer’s. ‘When I went back to my doctor after six weeks for a blood test, I told him how dreadful I was feeling,’ says John. ‘But he just said all drugs had side-effects and didn’t mention reducing the dose.’ It's claimed GPs are failing to warn patients of the effect statins can have on the mind - meaning they may mistake them for signs of ageing or Alzheimer's Things came to a head when a friend showed John an electrical circuit he’d built for his car. ‘I’d worked with circuits since I was 16 but it made no sense,’ he says. So John insisted on seeing his doctor again and repeated his concerns about his rapidly declining memory. This time the GP told him he could start on another type of statin when he felt well enough, and so John stopped taking the drugs immediately. ‘It took a few months, but gradually my memory returned and I’ve got my concentration back. I can’t say for sure statins caused these problems, but it seems like too much of a coincidence.’ Earlier this year, the Food and Drug Administration (FDA) in the U.S. ordered statins must carry warnings that some users have reported cognitive problems including memory loss, forgetfulness and confusion. This followed a decision by the UK’s Medicines Healthcare Regulatory Agency (MHRA) to add memory problems to the list of  possible statin side-effects in late 2009. The FDA said reports about the symptoms were from across all statin products and age groups. Those affected reported feeling fuzzy or unfocused in their thought process — though these were found to be rare and reversible. The FDA also warned, following U.S. research, that patients on statins had a small excess risk of developing Type 2 diabetes — but stressed that the benefits of taking a statin still outweigh this. The MHRA had 2,675 reports for adverse drug reactions connected with statins between 2007 and 2011. Officially, side-effects are rare —affecting only 1 per cent of people on the pills — but some doctors say they are under-reported. Dr Malcolm Kendrick, a GP and author of The Great Cholesterol Con, says he frequently sees patients suffering from mental confusion in his job in hospital intermediary care for the elderly. ‘Many of the patients I see will have been admitted to hospital after a fall or similar crisis,’ he says. ‘If they appear confused I’ll often advise taking them off statins to see if it has any effect — in my experience, about 10 to 15 per cent of people who appeared to have memory problems experienced an improvement in their memory symptoms after being taken off the drug. ‘I had one dramatic case where a lady was admitted to hospital on 40mg a day of simvastatin with such poor memory function her family asked me about power of attorney. 'I suggested taking her off statins and within a week her memory had returned to normal. She went home a fit and independent 83-year-old.’ Dr Kendrick says cholesterol is the main constituent of synapses (structures that allow signals to pass between brain cells and to create new memories) and is essential for brain function. ‘It is still not proven that statins have a significant effect on mortality — it has been calculated that a man who has had a heart attack who took a statin for five years would extend his life by only 14 days. 'Too many statins are being given to people at low risk. ‘Even in the highest risk group you need to treat 200 people a year with statins to delay just one death. 'One day the harm these drugs are doing is going to be obvious — the benefits are being over-hyped and the risks swept under the carpet.’ While Dr Kendrick’s controversial view is in the minority, one large review of 14 studies by the London School of Hygiene and Tropical Medicine, published by the highly respected Cochrane Library last year, concluded there was ‘little evidence’ cholesterol-lowering drugs protect people who are not at risk of heart disease. This review has been criticised by other doctors who say side-effects are rare and that there are still benefits even for people at lower risk who do not have established heart disease. These defenders of statins include Professor Colin Baigent of the Clinical Trial Service at Oxford University, who published research in 2010 showing statins reduced deaths from all causes by 10 per cent over five years. ‘There is relatively little evidence of cognitive impairment — what evidence there is all comes from observational studies.  ‘People read about side-effects and then put two and two together and blame the statins for their muscle pain or other health problems — it’s just not reliable evidence. ‘If you look at the best-quality randomised controlled trial where patients don’t know if they are taking a statin or placebo, there is no evidence of memory problems. 'Even the FDA says the risks of cognitive problems are very small and go away when statins are discontinued. ‘We’re in danger of forgetting just how effective these drugs are.’ Dr Dermot Neely of the charity Heart UK, and lead consultant at the Lipid and Metabolic Clinic at the Royal Victoria Infirmary in Newcastle, agrees side-effects with statins are rare. ‘I’ve been dealing with patients on statins since 1987 and I can count on the fingers of one hand the number whose memory symptoms turned out to be caused by statins.’ However, he said he often saw patients who had not been told about side-effects. ‘It’s important GPs are clear about the drugs statins can interact with, such as certain antibiotics, as this can get overlooked. ‘If a patient notices an adverse effect after starting statins, they should discuss this with their GP —but not stop their drugs suddenly because this can be dangerous.’ Sonya Porter, 73, decided to stop taking statins after her memory problems became so bad that she walked away from a cashpoint leaving her money behind. ‘I was permanently fuzzy-headed and just couldn’t seem to concentrate,’ says Sonya, a retired PA from Woking, Surrey. Then I started to get scared I might have Alzheimer’s. After reading about memory problems associated with statins, I thought it was at least a possibility. I decided to come off the pills to see if it made any difference. ‘I didn’t ask my GP, I just did it — I’d rather die of a heart attack than Alzheimer’s disease. Within a month I felt normal again and didn’t have any problems with memory. ‘I’m terrified that I could have been misdiagnosed with Alzheimer’s.’ John Holliday is also reluctant to go back on statins. ‘I wouldn’t rule it out completely — my latest test showed my cholesterol levels have gone up,’ he says. ‘But on balance, I’d rather take my chances with heart disease than feel as confused as that again. It’s all very well living slightly longer — but it’s about quality of life, too.’

BRIT Government 'planning new Internet snooping laws'

The British government wants to expand its powers to monitor email exchanges and website visits, The Sunday Times reported. Internet companies would be instructed to install hardware to allow the Government Communications Headquarters (GCHQ) to go through "on demand" every text message and email sent, websites accessed and phone calls made "in real time, the paper said. The plans are expected to be unveiled next month. The Home Office said ministers were preparing to legislate "as soon as parliamentary time allows" but said the data to be monitored would not include content. "It is vital that police and security services are able to obtain communications data in certain circumstances to investigate serious crime and terrorism and to protect the public," a spokesman said. "We need to take action to maintain the continued availability of communications data as technology changes. "Communications data includes time, duration and dialling numbers of a phone call, or an email address. "It does not include the content of any phone call or email and it is not the intention of government to make changes to the existing legal basis for the interception of communications." An attempt to bring in similar measures was abandoned by the Labour government in 2006 amid strong opposition. However, ministers in the Conservative-Liberal Democrat coalition government believe it is essential that the police and security services have access to such communications data in order to tackle terrorism and protect the public. The plans would not allow GCHQ to access the content of communications without a warrant. However, they would enable the agency to trace whom a group or individual had contacted, how often and for how long, the report said.

Eight people from 'Holy Death' cult arrested in Mexico over ritual sacrifices of woman and two 10-year-old boys

Eight people have been arrested in northern Mexico have over the killing of two 10-year-old boys and a woman in what appears to be ritual sacrifices. Prosecutors in Sonora, in the north-west of the country have accused the suspects of belonging to the La Santa Muerte (Holy Death) cult. The victims' blood has been poured round an altar to the idol, which is portrayed as a skeleton holding a scythe and clothed in flowing robes. The cult, which celebrates death, has been growing rapidly in Mexico in the last 20 years, and now has up to two million followers. Jose Larrinaga, spokesman for Sonora state prosecutors, said the most recent killing was earlier this month, while the other two were committed in 2009 and 2010. Their bodies were found at the altar site in the small mining community of Nacozari, 70 miles south of Douglas, Arizona. Investigations were launched after the family of 10-year-old Jesus Octavio Martinez Yanez reported him missing early this month.