The Teen Brain on Weed

April 24, 2015

By Medical Discovery News

A brain

It is now legal to use marijuana (recreationally and/or medically) in more than 20 states and the District of Columbia, and as more places debate legalizing the substance, more people are asking about its consequences on human health. There are many myths and misconceptions out there, but this is what science has to say about the subject.

As with all substances, the health effects depend on the potency, amount, and a person’s age. An independent scientific committee in the United Kingdom evaluated how harmful various drugs were based on 16 criteria and ranked heroin, crack cocaine, and methamphetamine as the most harmful drugs to individuals using them, and ranked alcohol, heroin, and crack cocaine as the drugs that cause the most harm to others. Marijuana ranks eighth, with slightly more than one-quarter the harm of alcohol.

Short-term use is associated with impaired short-term memory, making it difficult to learn and retain information while under the influence. Short-term use can also impair motor coordination, interfering with tasks such as driving. The overall risk of an accident doubles if a person drives soon after using marijuana. In comparison, those with blood alcohol levels above the legal limit are five times more likely to have an accident, and the combination of alcohol and marijuana is higher than either one alone.

Long-term or heavy use is associated with diminished life satisfaction and achievement overall. At high doses, marijuana can cause paranoia and psychosis, and long-term marijuana use increases the risk of developing schizophrenia or other chronic psychotic illnesses. Nine percent of all marijuana users, or 2.7 million people, develop an addiction to it. That figure jumps to 25-50 percent for those who use marijuana daily, and 17 percent of people who begin using marijuana as adolescents become addicted. Cannabis withdrawal syndrome is real and includes symptoms of irritability, sleep disturbance, dysphoria, craving, and anxiety.

Adults who occasionally use marijuana do so with little to no risk, but adolescent brains are not fully developed, making them more vulnerable to the adverse effects of marijuana. Using marijuana during adolescence can alter brain development, causing impaired cognition and lower IQs. This is probably because the active ingredient in marijuana, tetrahydrocannabinol, affects the brain’s ability to make connections between neurons in certain regions of the brain. Adolescent marijuana users also have a smaller hippocampus, which is important in learning and memory, and a less active prefrontal cortex, which is important in cognitive tasks such as planning and problem-solving.

Since acute marijuana intoxication can impair cognitive functions for days, students who use marijuana may function well below their natural abilities, causing academic difficulties. High school dropouts do report higher marijuana usage than their peers. Some evidence suggests that these cognitive impairments could be long-lasting or permanent in long-term users who started at younger ages, which can impact their abilities to succeed academically and professionally.

There is no clear association between long-term marijuana use and any deadly disease, although chronic marijuana smokers have increased rates of respiratory infections and pneumonia and an increased risk of heart attack and stroke. The effects of marijuana on a developing embryo and the effects of second-hand or third-hand marijuana smoke have not been well-studied, but as marijuana legalization continues to be an issue the science behind it will as well.

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An Update on Mad King George

By Medical Discovery News

June 23, 2012

King George III

Before the planet Uranus was given its present-day name, it was called Georgium Sidus, after King George III of Great Britain. Not only was King George a patron of the sciences, under his rule slavery was abolished in England and the country’s Industrial Revolution began. Despite these significant contributions, he’s most remembered for losing America, and for being the Mad King.

A 1994 movie, “The Madness of King George,” depicted the court intrigue surrounding the King’s illness and his son’s maneuvering to become regent and rule the kingdom. In the film, the cause of the King’s mental state is suggested as intermittent porphyria, which has been an accepted diagnosis among many scientists.

Now a new study disputes this claim. TJ Peters and A Beveridge reevaluated King George’s medical records and believe Ida Macalpine and Richard Hunter based the porphyria diagnosis on an incomplete review of historical records. They are a mother and son, both psychiatrists, who studied health accounts of the King in the 1960s and theorized he had acute or variegate porphyria.

Porphyria disorders are a rare hereditary disease, which is the inability to make a key component of the oxygen-carrying molecule called heme.  People with porphyria are missing enzymes that produce heme molecules, which creates the build-up of a precursor biochemical called porphyrins. This can result in abdominal pain, muscle weakness, nervous system deficits, and personality changes. The disease lasts a lifetime and acute attacks and symptoms can appear and disappear over many years.

Those who believe porphyria caused King George’s mental problems point to the drugs and treatments he was given as being partially responsible. Many of those medications contained arsenic, a poison that scientists found in high levels when they tested the King’s hair.

But Peters and Beveridge believe neither medication nor porphyria are to blame. They believe the King’s mania was more likely symptomatic of a recurring bipolar disorder. The researchers examined medical records along with journals from his caretakers and were able to document four bouts of mental illness. His psychiatrists, called “mad doctors” at the time, treated King George and documented these episodes of psychosis. The first happened when he was 50, and then he spent the last ten years of his life suffering chronic mania and dementia.

The researchers further speculate King George’s other health problems may have contributed to his mental decline. At 70 he was blind from cataracts and thought to be increasingly deaf. The isolating effect of these lost senses may have contributed to his eventual chronic mania.  Records also show the king’s favorite daughter, Amelia, died when he was 70. By the end of that year he was declared permanently insane and lived in seclusion at Windsor Castle until his death at 81 years old.

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