Category: Addiction

Your Brain On Cannabis: Part Three

Welcome to the final part of this three part series on the effects of cannabis on the brain, and today we look at marijuana as medicine.

There are several well-documented beneficial effects of marijuana including the amelioration of nausea and vomiting, stimulation of hunger in chemotherapy and AIDS patients, lowered intraocular eye pressure (shown to be effective for treating glaucoma), as well as general analgesic effects (pain reliever).

The first treatment to emerge from understanding cannabinoids is the drug rimonabant, recently approved in Europe to treat obesity and related metabolic conditions. The drug works by binding to receptors in the brain and body organs to block cannabinoid action. Studies have shown that an overactivated cannabinoid system in brain areas like the hypothalamus -which is involved in appetite increases food intake and fat accumulation. Rimonabant and similar compounds reduce cannabinoid overstimulation to help normalize appetite, body weight and fat, and also cholesterol levels. Drugs that decrease cannabinoid action also may cause anxiety or depression-side effects scientists are working to combat.

Research is underway to determine if rimonabant also will help smokers and heavy drinkers quit. Scientists believe that rimonabant could work in these conditions by reducing levels of the chemical dopamine in the brain’s motivation centers, which nicotine and other addictive drugs trigger.

In 2011, an oromucosal spray for Multiple Sclerosis patients became licensed for use as a medicine in Canada and parts of Europe, allowing it to be routinely prescribed by doctors. This drug reduces the pain, tremor, and muscle spasms associated with this disease.

Synthesized cannabinoids are also sold as prescription drugs, including Marinol (dronabinol) in the United States and Germany and Cesamet (nabilone) in Canada, Mexico, the United States and the United Kingdom. Canada, Spain, The Netherlands, Austria and fourteen states in the US have legalized some form of cannabis for medicinal use.

I regularly visit schools to explain how addictive drugs including cannabis affect the brain.

Click to arrange a speaking engagement.

For those interested in the topic of marijuana abuse more information can be found at: http://drugabuse.gov/ResearchReports/Marijuana/marijuana3.html


Your Brain On Cannabis: Part Two

This a follow on post from last month’s Your Brain On Cannabis, which has become one of the most widely read posts on Inside the Brain.

The effects of marijuana on your brain

The drug acts in areas of the brain involved in memory and emotion by interacting with two receptors – the so-called CB1 and CB2 cannabinoid receptors – to cause a profound effect on recent memory. Long term memories are not affected. One brain region called the hippocampus has receptors for endogenous “marijuana” (anandamide). Hippocampal damage is associated with failure to make new memories and if the CB1 and CB2 receptors are stimulated activity decreases in this brain region.  Interestingly, with repeated use, tolerance to loss of memory develops but this is often associated with a further increase in drug intake.

Learning and marijuana don’t mix

Marijuana also changes the way sensory information is processed in the brain and is associated with poor performance in school and increased delinquency. There is impairment in the ability to learn. Listening and repetition learning is also compromised. Heavy marijuana use is associated with deficits in mathematical skill and verbal expression. Taken together these effects can lead to catastrophic social and psychological consequences particularly for the young abuser – not to mention the lost employee productivity, public health care costs, accidents and crashes and loss of income – Americans spent $10.6 billion on marijuana purchases in 1999.

Marijuana is addictive

Marijuana addicts experience withdrawal and an animal model for dependence has been developed by scientists to understand how this happens. Withdrawal has been described after 21 days of heavy use and starts 10 hours after stopping and includes insomnia, nausea, anorexia, agitation, restlessness, irritability, depression and shaking (tremor). The symptoms peak within 48 hours and gradually wear off by the fifth day of abstinence.

The war on marijuana starts with spreading the word

During the 1970s in the US it was decided that a liberal approach be adopted to marijuana use and 11 states decriminalized marijuana, 30,000 head shops were allowed to spring up and “responsible-use” messages were promoted. The drinking age was lowered to 18 years and the sale of cigarettes and alcohol to teens was tolerated. By 1979 35% of adolescents, 65%of high school seniors and 70%of young adults had tried an illicit drug. These facts and the increase in drug-related crime prompted universal outrage and the laws were tightened up. As a result – from 1979 to 1992 marijuana use has dropped by 2/3 among adolescents, and young adults and daily marijuana use has dropped by 500%. However, it has taken over 20 years to undo the damage in the US.

In tackling the marijuana problem head-on  – the following common myths need to be debunked (i) marijuana is harmless, (ii) marijuana is not addictive (iii) youth experimentation is inevitable and (iv) the criminalization of marijuana use is what leads to crime, not the drug itself.

In the final part of this series on the effects of cannabis on your brain, we will take a look at the possible medicinal uses of marijuana.


Weekly Update: Brain Research

Using a sling or cast after injuring an arm may cause your brain to shift quickly to adjust, according to a study published in the January 17, 2012, print issue of Neurology®. The study found increases in the size of brain areas that were compensating for the injured side, and decreases in areas that were not being used due to the cast or sling.

A  new UC Davis study shows how the brain reconfigures its connections to minimize distractions and take best advantage of our knowledge of situations.

Neuroscientists at Kessler Foundation have documented increased cerebral activation in patients with multiple sclerosis (MS) following memory retraining using the modified Story Memory Technique (mSMT).  This is the first study to demonstrate that behavioral interventions can have a positive effect on brain function in people with cognitive disability caused by MS, an important step in validating the clinical utility of cognitive rehabilitation.

A program designed to boost cognition in older adults also increased their openness to new experiences, researchers report, demonstrating for the first time that a non-drug intervention in older adults can change a personality trait once thought to be fixed throughout the lifespan.

Researchers from the Institute of Psychiatry (IoP) at King’s College London have, for the first time, identified the facial expression of anxiety. The facial expression for the emotion of anxiety comprises an environmental scanning look that appears to aid risk assessment. The research was published this week in the Journal of Personality and Social Psychology.

New research from Uppsala University, Sweden, shows that a specific brain region that contributes to a person’s appetite sensation is more activated in response to food images after one night of sleep loss than after one night of normal sleep. Poor sleep habits can therefore affect people’s risk of becoming overweight in the long run. The findings are published in the Journal of Clinical Endocrinology & Metabolism.

Teenagers are more susceptible to developing disorders like addiction and depression, according to a paper published by Pitt researchers Jan. 16 in the Proceedings of the National Academy of Sciences.

Harvard scientists have developed the fullest picture yet of how neurons in the brain interact to reinforce behaviors ranging from learning to drug use, a finding that might open the door to possible breakthroughs in the treatment of addiction.

Virtual reality-enhanced exercise, or “exergames,” combining physical exercise with computer-simulated environments and interactive videogame features, can yield a greater cognitive benefit for older adults than traditional exercise alone, according to a new study published in the February issue of the American Journal of Preventive Medicine.

Sleeping after a traumatic event might lock in bad memories and emotions, a new study has found.

A team of researchers at the MedUni Vienna’s Department of Neurophysiology (Centre for Brain Research) has discovered a previously unknown effect of opioids – that opioids not only temporarily relieve pain, but at the right dose can also erase memory traces of pain in the spinal cord and therefore eliminate a key cause of chronic pain.

 

Your brain on cannabis

A recent article in the Irish Times exploring how a new, highly potent strain of cannabis now being grown in Ireland is more harmful than the drug’s benign image would suggest, prompted me to write about the topic this week.

Marijuana can hurt you

The marijuana problem is much bigger than previously recognized. It is the most widely used illicit drug in the world. Of the 5.6 million people suffering in the US, 62% are using marijuana and young people – some now as young as 12 years of age – represent 23% of the suffering population. The average age of initiation is decreasing while marijuana’s potency is increasing. With increasing potency and earlier use, marijuana poses a significant threat. It is no surprise then that of all teens in drug treatment, 62% have primary marijuana diagnosis. That number represents more young people in treatment than for alcohol and almost equal to the numbers from criminal justice and other sources

Route of administration

Marijuana (from the Mexican Spanish marihuana) also known as cannabis, is much more powerful today than it was 30 years ago. Marijuana is the herbal form of cannabis, and comprises the flowers, leaves and stalks of the mature female plant while hashish is the resinous, concentrated form of cannabis. Chemically, the major psychoactive compound in marijuana is Delta-9-tetrahydrocannabinol (Δ9-THC); it is one of 400 compounds in the plant The smoke also contains more than 150 other types of these cannabinoids such as cannabidiol (CBD), cannabinol (CBN), and tetrhydrocannabivarin (THCV), which can produce sensory effects unlike the psychoactive effects of THC. The pharmacology of marijuana is complex. The cannabinoids are vaporized (smoke) and then deeply inhaled. They are fatty compounds which rapidly cross from the lungs into the blood and tend to accumulate in specific regions of brain.

The psychological effects of marijuana – a Pandora’s Box

The immediate (acute) effects of marijuana include changes in time-sense, a loss of recent memory and impairment in attention. There is also a general difficulty expressing simple thoughts in words. Other effects include impaired motor skills, increase in hunger, nausea, dizziness, and  – depending on the personality of the person and the context in which it is taken – altered moods such as euphoria, a state of relaxation, panic, anxiety, tension, anger, confusion and – especially when eaten – an unpleasant sensation called depersonalization.

The effects on your body are not good either

Marijuana smoke contains more than 150 compounds many of which are cancer–causing so the respiratory system including the lungs suffer the most. Common symptoms include air obstruction, chronic cough, bronchitis, decreased tolerance to exercise and cancer. An increase in heart rate can aggravate existing cardiac conditions or high blood pressure (hypertension) – so don’t take this drug if you have a weak heart.

Definitely not good for your MOJO

Marijuana decreases blood testosterone levels, sperm count and motility. It also decreases sex-drive (libido) and impairs fertility as well as disrupting the female reproductive system which can impact pregnancy in adverse ways. The effect of the drug on the immune system is still unclear but recent studies in animals demonstrate that it impairs T helper cells – key cells in the immune system – which may increase the risk of cancer (by disrupting the cancer surveillance system).

In Part Two of Your Brain On Cannabis, we will take a closer look at the effects of marijuana on your brain, how the drug affects how you learn, how to counter the argument that it is a harmless drug, and if there is any scientific basis for using marijuana as medicine.

Weekly Round Up

Image Source: The Dana Foundation

Our senses of sight and hearing work closely together, perhaps more than people realize, a new UCLA psychology study shows.

A team of neurobiologists  has shown for the first time that cortex, the largest area of the brain that is typically associated with higher functions such as perception and cognition, is also a prominent site of emotional learning.

Tiny electric currents applied across regions of the brain can improve hand movements in recovering stroke patients for a short period, an Oxford University study has demonstrated.

For the first time, scientists have proven that cannabis harms the brain. But the same study challenges previously-held assumptions about use of the drug, showing that some brain irregularities predate drug use.

How might keeping patients awake during surgery lead to the more successful removal of brain tumours? James Keidel, in his shortlisted entry for the 2011 Wellcome Trust Science Writing Prize, explains.

Researchers from the University of Bristol have discovered that a chemical compound in the brain can weaken the synaptic connections between neurons in a region of the brain important for the formation of long-term memories. The findings, published in the Journal of Neuroscience, may also provide a potential explanation for the loss of memory associated with Alzheimer’s.

The Craving Brain

This is a terrific animated film which describes the pathology of addiction according to the theories presented in Dr. Ronald Ruden’s book The Craving Brain.

Ruden maintains that all addictions are “craving disorders” of the brain, caused by a “craving response” to life experiences and environment. A craving brain is a brain chemically out of balance, and the solution is to put it back into balance, or “biobalance.”

This video also outlines the role that chronic, inescapable stress contributes to addictive behavior.

Once we understand these responses, and understand the landscape of the craving brain, we can then learn to balance the brain (biobalance) by adopting healthy, serotonin-boosting habits.

What is dopamine?

Dopamine is a neurotransmitter that helps control the brain’s reward and pleasure centers. Dopamine also helps regulate movement and emotional responses, and it enables us not only to see rewards, but to take action to move toward them.

Dopamine deficiency results in Parkinson’s Disease, and people with low dopamine activity may be more prone to addiction. Most abused drugs cause the release of dopamine and this is thought to contribute to their addictive properties.

This video describes some of the cognitive functions of dopamine in your brain.

Weekly Round Up

What can neuroscience teach us about making predictions?

Every day we make thousands of tiny predictions — when the bus will arrive, who is knocking on the door, whether the dropped glass will break. Now, in one of the first studies of its kind, researchers at Washington University in St. Louis are beginning to unravel the process by which the brain makes these everyday prognostications.

Imitation may be the sincerest form of flattery but how do our brains decide when and who we should copy? Researchers from The University of Nottingham have found that the key may lie in an unspoken invitation communicated through eye contact.

Cognitive training can enhance working memory and the release of the neurotransmitter dopamine, according to a study published recently in the journal Science.

The American Society of Addiction Medicine (ASAM) just released this new definition of addiction after a four-year process involving more than 80 experts: “Addiction is a chronic brain disorder and not simply a behavior problem involving alcohol, drugs, gambling or sex, experts contend in a new definition of addiction, one that is not solely related to problematic substance abuse.”

Finally, IBM has been shipping computers for more than 65 years, and it is finally on the verge of creating a true electronic brain. It has just announced that along with four universities and the Defense Advanced Research Projects Agency (DARPA), it has created the basic design of an experimental computer chip that emulates the way the brain processes information.

Weekly Round-Up

Your brain is more responsive to your friends than to strangers

Researchers from UT Southwestern Medical Center have described for the first time how the brain’s memory center repairs itself following severe trauma – a process that may explain why it is harder to bounce back after multiple head injuries.

People with autism use their brains differently from other people, which may explain why some have extraordinary abilities to remember and draw objects in detail, according to new research from the University of Montreal.

Five more genes which increase the risk of developing Alzheimer’s disease have been identified, according to research published in Nature Genetics. This takes the number of identified genes linked to Alzheimer’s to 10 – the new genes affect three bodily processes and could become targets for treatment. If the effects of all 10 could be eliminated the risk of developing the disease would be cut by 60%, although new treatments could be 15 years away.

The sudden understanding or grasp of a concept is often described as an “Aha” moment and now researchers from New York University are using a functional MRI (fMRI) scanner to study how these moments of insight are captured and stored in our brain.

Mark Changizi is asking the question how do we have reading areas for a brain that didn’t evolve to read?

In order to develop new medications for alcoholism, researchers need to understand how alcohol acts on the brain’s reward system. A previously unknown mechanism has been shown to block the rewarding effects of alcohol on the brain, reveals a thesis from the University of Gothenburg, Sweden.

Researchers from the University of Valencia (UV)  investigating the brain structures involved with empathy have concluded that the brain circuits responsible are in part the same as those involved with violence.

And finally…your brain is more responsive to your friends than to strangers, even if those strangers have more in common with you, says a new study. Researchers looked at the brain areas associated with social information. The results of the study show that social connections override similar interests.

What can we learn from Gerry Ryan’s death?

Gerry Ryan

I was saddened this week to read of the coroner’s verdict on the death of the radio DJ and TV personality Gerry Ryan (53). I have vivid memories of listening to Gerry late into the night in the mid 1980’s as I worked away in the Pharmacology laboratory in University College Galway, Ireland – on my experiments for my PhD degree on possible mechanisms of action of antidepressant drugs.

It was the middle of a devastating recession with thousands of young people including myself preparing to emigrate and very unsure of what fate awaited us. I vividly recall a riveting moment when alone in the lab one evening I was literally stuck to the floor as the then popular Terence Trent Darby’s song ‘Sign you name across my heart’ came on air and in the background was Gerry’s weary yet empathetic voice saying…’I wish you well my friends as you sign your name on your passports, on your visas, on you dole cards.’  It must be over 25 years ago but that memory has always remained with me. The power of memory! But that’s for another blog post.

Cocaine and Alcohol – a potentially lethal mix

Over the past two decades I have given talks in schools and colleges on how addictive drugs including cocaine affect the brain and it still amazes me how little the general public understand  how these potentially lethal drugs work.

The post mortem showed the Gerry had died from an abnormal heart rhythm which was likely to have been triggered by cocaine. Gerry also had “cocaethylene” in his system, which is produced when cocaine and alcohol are mixed.

Both cocaine and alcohol have very different modes of action on the brain. Cocaine is a stimulant which elevates mood, increases heart rate and puts your brain into a vigilant attentive state. Alcohol is what’s called a narcotic- a nervous system depressant – which puts you to sleep. What both drugs have in common however is that both are highly addictive.   Not only that but some studies show that when alcohol is taken before (the cocaine), it causes a greater buzz and that an alcohol and cocaine combination is 25pc more potent. To make matter worse at high enough doses both alcohol and cocaine are anesthetics – drugs that switch off important nervous functions – which does not help either.

More harmful drugs found in the cocktail

Other drugs also found in Gerry’s body were Levamisole, a veterinary medicine until recently used to treat parasitic worm infections in humans and commonly used as a cutting agent in cocaine where it adds bulk and weight to powdered cocaine (whereas other adulterants will produce smaller “rocks” of cocaine) and makes the drug appear more pure.

Also found was a small quantity was codeine – a powerful pain killer from the opiate family of morphine-like drugs –  and sold over-the-counter as Nurofen Plus or Solpadine.  Gerry probably took this because he was in some discomfort.

It is clear from reading newspaper reports that Gerry Ryan’s friends and loved ones are deeply shocked by the revelations of the inquest, insisting they had no idea about Ryan’s cocaine use. It is particularly sad that our memories of this popular broadcaster may be tarnished by the revelation. Many of his media friends have urged people not to let this be the case, and to remember Gerry for his talent and not the sordid nature of his death.

Today FM broadcaster Ian Dempsey has told the Herald newspaper that he would “It’s a pity that something like this has to overshadow what he achieved during his life. I don’t think it’s of any benefit to anyone.”

While I agree to an extent with Dempsey, I do think that Gerry’s death might be of some benefit if it opens up a debate on how we as a society deal with stress. We have heard that Gerry was under a great deal of stress in the days and weeks leading up to his death, and we are led to surmise that alcohol and drug taking was his way of coping. In this he is not alone. As the world economy continues on its downward slide, and unemployment and financial worries beset us, are we going to turn more and more to these quick fixes to handle our dis-stress?

Probably the most important lesson to be taken from Gerry’s death is the realization that the stresses of life and how we manage them IS the difference between life and death. I look forward to developing this theme in greater detail including drug-free tips on how the avoid worry and stress in future posts, but in the meantime, my deepest sympathy go to Gerry’s loved ones at this difficult time.