We Are Our Brains

by D. F. Swaab

  Adult males who smoke marijuana daily for a period of years have been found not only to have a smaller hippocampus (important for memory), a smaller amygdala (affecting fear, aggression, and sexual behavior), and damage to the fiber tracts of the corpus callosum (left-right connections) but also to be more likely to develop a psychosis. Again, though, these characteristics may have been present before using cannabis.

  Not every psychosis after cannabis use is the first sign of schizophrenia. Gerard, a Dutch student, was mountain climbing in New Mexico. In the evening, when his group was sitting around the camp-fire, one of his fellow climbers offered him a joint. After four puffs he experienced hallucinations with flashes of light, became extremely hot, felt dehydrated, developed a burning spot in his heart region along with cardiac arrhythmia, lost all power in his legs, and fainted twice. His friends took him to a hospital in El Paso, where he was told, not very helpfully, that he had had a “bad trip” and could go home again. Afterward he found out that the previous day, one of the other climbers had had a similar problem with that batch of cannabis, so they threw the rest away. The next day Gerard was left with the feeling that there was something odd about his sensory perceptions as well as the world in general (derealization), and he felt very tired. After a few days he had recovered sufficiently to join the next climbing trip. A month after the bad trip, after three days of climbing and considerable physical effort, he suddenly had the same symptoms as before, including the sensation of derealization, a feeling of acting on automatic pilot and observing himself from a distance (depersonalization), a tendency to faint, and serious difficulties in concentrating—something he found particularly worrying. Back in the Netherlands, doctors tried to get to the bottom of his extreme reaction to cannabis. Fortunately, he hadn’t had the classic psychosis resembling a schizophrenic episode but had perhaps been intoxicated by a high dose of THC. In the Mexican border region, cannabis is said to be often far stronger than elsewhere. Someone put forward the theory that THC can remain in fat tissue for a very long time, to be released in response to intense physical effort. Moreover, Americans appear to smoke “pure” cannabis on the whole, unmixed with tobacco, causing a greater risk of adverse effects. (When on vacation in Amsterdam, they also put much too much THC in a single joint.) Another possible explanation was that the cannabis Gerard smoked had been sprayed with chemical agents or adulterated, possibly with a toxic weed killer or angel dust. None of these theories could be proven. Luckily, he made an excellent recovery. He’s back at university and recently scored high grades on his exams.

  Cannabis has lost its innocence. It’s much stronger than it used to be and much less harmless than we all thought it was back in the 1960s. For some people, taking cannabis can have disastrous consequences. But compared to the enormous widespread damage that alcohol and cigarettes cause in our society, the problem remains a proportionately small one.

  ECSTASY: BRAIN DAMAGE AFTER PLEASURE

  Take me, I am the drug; take me, I am hallucinogenic.

  Salvador Dalí

  Ecstasy is now known as the “love drug,” but it was originally patented as an appetite suppressant in 1914. Its recreational use can be extremely dangerous. A year ago, a trainee nurse decided to write a thesis on ecstasy. She didn’t want to do so without any experience of the drug, so she tried it during the festival on Queen’s Day, an important Dutch holiday. Just to make sure she wouldn’t harm herself, she drank four liters of water. The experiment proved fateful. She lost consciousness, was in a coma for several days, and has been left with lasting brain damage, especially to the cerebral cortex.

  When you take ecstasy, you make quite a lot happen in your brain, as a pioneer in this field, the radiologist Liesbeth Reneman, established many years ago, and the risks are considerable. Twenty minutes after swallowing ecstasy, increased amounts of the chemical messengers serotonin, oxytocin, and vasopressin are released. All tiredness vanishes and you feel happy and want to hug everyone. The pleasurable feelings of love and wonderful social interaction last for an hour. If you take a fair amount of ecstasy every weekend, you destroy the brain cells that make serotonin. Less of this messenger is produced, and you function less well. You also need more ecstasy each time in order to get the same pleasant effect. Users are more likely to develop psychiatric and neurological problems like mood disorders, aggression, impulsiveness, and memory impairment. Brain scans of ecstasy users indeed show permanently reduced activity in structures that would be involved in such problems, like the amygdala, hippocampus, thalamus, and cerebral cortex. A recent follow-up study showed that even brief, extremely limited ecstasy use amounting to a couple of pills taken over an eighteen-month period impairs memory and blood flow in the thalamus and cerebral cortex. Scans have also shown that ecstasy can cause blood vessels to constrict or, conversely, to dilate on a long-term basis, depending on the brain region in question. The neurological consequences can include brain infarcts or bleeding on the outside of the brain, resulting in serious and lasting neurological damage.

  If you take ecstasy when it’s hot and you don’t drink enough, you can dehydrate, resulting in organ failure. Some people develop palpitations or have a sudden fatal heart attack. Unity, a voluntary project sponsored by the Jelinek addiction treatment center in the Netherlands, therefore rightly advises ecstasy users to drink a glass of water or a sports drink every hour to prevent dehydration and overheating. But apparently people also need to be explicitly warned that drinking too much water in combination with ecstasy can also be dangerous. Ecstasy causes the pituitary gland to release much more vasopressin (the antidiuretic hormone; see chapter 5), so your kidneys retain all the liquid you drink. As a result, drinking too much can cause water poisoning and serious brain damage.

  This is exactly what happened to the trainee nurse researching her thesis: She developed brain and vascular edema—essentially a swelling of the brain—causing serious brain damage. After three days she gradually emerged from the coma, suffering subsequent epileptic attacks. A scan showed severe swelling of the brain, mainly on the left-hand side. In the early weeks she couldn’t talk (Broca’s area, bottom left of the frontal cortex, fig. 8) or walk (motor cortex, fig. 22) and her sight was impaired on one side (visual cortex, at the rear of the brain, fig. 22). She’s still recuperating with therapy. She can’t yet read and finds writing difficult. When she speaks, she regularly struggles for words. Recovery is a slow, demanding process, and she’s continually tired. It’s not yet clear what permanent impairment will result from her brush with ecstasy, but an MRI scan shows damage to the cerebral cortex. Instead of writing a thesis on ecstasy, she now wants to warn schoolchildren about its dangers, particularly in combination with a lot of water. Her own ecstasy party is over for good.

  SUBSTANCE ABUSE BY POLITICIANS

  Drunkenness is nothing more than voluntary madness.

  Seneca

  The terms addiction and substance abuse mainly conjure up images of neglected, homeless, and often schizophrenic people. But the former British cabinet minister David Owen, a neurologist by training, makes clear in his startling 2008 book In Sickness and in Power: Illness in Heads of Government During the Last Hundred Years that the problem of substance abuse can be found even in the highest government circles, with potentially dramatic consequences for the course of history.

  Teenagers experiment with pills, magic mushrooms, marijuana, and other potentially dangerous substances. This seems to be a normal aspect of adolescent behavior (see chapter 4). Some world leaders have been forced to confess to similar youthful peccadilloes, which isn’t always easy. During his 1992 campaign, Bill Clinton was forced to admit that he had smoked pot as a student, adding rather feebly, “But I didn’t inhale.” But America has become more tolerant of these things in recent years. When Barack Obama sought the presidential nomination, he was questioned about his book Dreams from My Father, in which he wrote about smoking pot and drinking as a troubled teenager, and he owned up to the occasional hit.
“I inhaled frequently—that was the point,” he said, poking fun at Bill Clinton. This open admission never worked against him.

  Before his presidency, George W. Bush was an alcoholic, and certainly not just as an adolescent. At the age of thirty he was arrested for drunk driving and lost his driver’s license for two years. During his 2000 campaign he stated that in 1986 he woke up with a hangover after celebrating his fortieth birthday and that he had not drunk a drop since. That claim seems a little questionable. In 2002, Bush fell off a couch while watching a football game and was taken to the Johns Hopkins Hospital in Baltimore. A British doctor there told David Owen that Bush’s blood contained significant amounts of alcohol. Bush has refused to answer any questions about his alleged past cocaine use.

  There’s no doubt at all, however, about Richard Nixon’s alcoholism during his presidency. In 1969, when an American spy plane was shot down in North Korea, Nixon stormed about in a drunken rage, telling his national security advisor, Henry Kissinger, “Henry, we’ll nuke ’em!” Tapes released after the Arab-Israeli conflict in 1973 also revealed that Nixon was too drunk to discuss the situation with his British counterpart. Russian president Boris Yeltsin suffered severe back pain after being in a Spanish plane that was forced to execute a crash landing. Beginning in 1994 he took more and more painkillers and drank increasingly. At an official ceremony that year in Berlin, in honor of the departure of the last Russian troops, he was clearly drunk. There was another incident that same year when his plane stopped over at Shannon International Airport. The entire Irish government stood ready to welcome him at the foot of the aircraft steps, but he was sleeping off the effects of a drinking bout and failed to appear.

  Not that alcoholism is confined to presidents, of course. The American Communist hunter Senator Joseph McCarthy, who destroyed many lives, had a serious alcohol problem and died in 1957 of cirrhosis of the liver. And alcohol certainly isn’t the only substance abused by world leaders while carrying out their duties. In 1956, during the Suez crisis, British prime minister Anthony Eden, who was suffering from severe pain, took pethidine, an opium derivative, shortly before chairing a cabinet meeting. He took barbiturates to sleep and amphetamines to stay alert. Indeed, in the final weeks before his resignation he lived on amphetamines, a fact that he didn’t conceal from his cabinet.

  Some leaders have been successful despite mental health problems and substance abuse. Winston Churchill not only suffered from severe depression but also had hypomanic and manic phases (see chapter 5) in which he drank phenomenal amounts of champagne, brandy, and whiskey. John F. Kennedy had numerous health problems, including Addison’s disease, caused by the failure of the adrenal glands, for which he had to take cortisol. At some point during his election campaign he forgot to take his cortisol tablets with him and fell into a coma. In 1938 he was involved in a car crash, after which he suffered from back pain. His treatment involved procaine injections that were administered three times a day or more. (Procaine is a synthetic cocaine derivative that can leak into the brain, causing central effects.) Kennedy was also a recreational user of substances like amphetamines, whose effects he described as delectable and euphoric. He took cocaine both before and during his presidency. He was also being given testosterone, allegedly because of his adrenal gland problem, but you might wonder whether that could have contributed to his irresponsibly macho behavior during the Bay of Pigs invasion of Cuba in 1961. He experimented with marijuana and LSD in the company of his mistresses at the White House. Kennedy also took sleeping pills, painkillers, and phenobarbital, a sedative. On top of that, he was given injections of a mixture of corticosteroids and amphetamines concocted by a doctor. Various doctors prescribed medication for him without knowing what other treatment he was receiving. It has been said that Kennedy played around with doctors even more than with women!

  Shouldn’t we at least impose the same requirements on those who govern the country as those who drive a car or fly a plane? When are we going to test politicians, on whom we’re so dependent, for alcohol, drugs, and medication?

  7

  The Brain and Consciousness

  NEGLECT: HALF A LIFE

  “If it isn’t there, then I can’t be ignoring it.”

  We are conscious of our surroundings and of ourselves. Some brain structures are crucial to consciousness, like the cerebral cortex, the thalamus (where we receive sensory information), and the white matter, the nerve fibers linking these structures (fig. 20). After a brain infarct on the right side of the brain, both self-consciousness and consciousness of surroundings can be impaired. It’s possible for a person not to be aware that they are paralyzed on the left side and to ignore everything on their left, not just in terms of their surroundings but also of their own body. This is known as neglect. If you approach such a patient’s bed from the left, even though he can turn his head and see you, he won’t notice you. When reading a newspaper, such patients will look only at the right-hand page, and when drawing, will draw only the right side of an object. They eat only what is on the right half of their plates. If you then turn the plate around 180 degrees, they will eat the other half. Neglect can extend to the left half of their bodies. They no longer regard their left arm or their left leg as part of themselves. They will dress or wash only their right side, and comb their hair only on the right side of their heads.

  Neglect patients frequently make up extremely imaginative stories to explain the bizarre situation in which they find themselves. Some claim that the hospital is their home and that they have chosen the furniture themselves. One patient remained convinced that her left side was fully functional and that she was physically independent. Yet in her drawings, the left half was completely lacking. “If it isn’t there, then I can’t be ignoring it,” she countered. When she was asked to move her left arm, she answered, “I could do that, but it would be better if I rested it now.” When she was asked to walk a few steps after she had claimed that there was nothing wrong with her, her response was, “Of course I could, but the doctors said I should rest.”

  The mother of a good friend of ours suffered a severe brain infarct on the right side when she was eighty-five, being left paralyzed on the left side. Her mind was still sharp, though, and she hadn’t lost her sense of humor. Indeed, her conversations with relatives, friends, and the nursing staff were perfectly normal, with one striking exception. One day she told me that she’d had a really odd dream in which she had a third arm. I carefully took hold of her paralyzed left arm and asked her, “Is this that third arm?” “No,” she said, “of course not, that’s Kees.” Kees was her fifty-five-year-old son. “What is Kees doing here?” I asked. “He’s sleeping in my bed, as he always does.” This was nonsense; I knew the family very well. “But tonight I needed him,” she went on, “and I couldn’t wake him up. The same thing happened the night before, when Kitty [her daughter’s friend, who visited her nearly every day and was very close to her] was sleeping here, and I couldn’t wake her up either,” she continued somewhat huffily. She asked if she could have something to drink and went on to speak perfectly normally about all kinds of matters that she wanted to arrange.

  The fantasies that arise in the case of neglect in fact spring from a very general principle. If something gets in the way of the brain’s information supply, it starts to make up information to fill the gaps. A damaged brain deprived of its customary input invents bizarre stories. It does similar things to compensate for the lack of oral or visual information or information from the memory or limbs (see chapter 7). Unconsciously filling up the little holes in our memory is something the brain does on a daily basis, even when it’s intact. We’re convinced that events happened exactly as we remember them and will state as much under oath in court. In fact, our brains are just knitting neat stories out of the countless scraps of information they receive, leading to all kinds of consequences.

  FIGURE 20. Three intact and properly functioning structures, shown here in black, are crucial to consciousness: an
intact cerebral cortex (left), the thalamus (right), and the white matter (center), with pathways connecting the cortex and thalamus.

  COMA AND RELATED CONDITIONS

  It’s as if he has been abandoned twice, first by his brain, then by the people who knew him. Because no one visits him.

  Bert Keizer, Inexplicably Inhabited, 2010

  A coma is a situation in which a patient can’t be woken and doesn’t respond to external stimuli. It can result from damage to the cerebral cortex, the thalamus, the connections between these two brain structures (fig. 20), or the brain stem (fig. 21), which activates the cerebral cortex and the thalamus. But it can also be caused by a metabolic disorder, drugs, or an excessive amount of alcohol. Some people recover from comas. One boy was driving back from a night out with friends when he crashed into a concrete post at high speed; the accident left him in a coma for six weeks. His family had already been approached about the possibility of his kidneys being donated for transplant. But they thought they detected slight signs of a return to consciousness, so they put off the decision. They were right, because he came out of his coma and completed his education at technical school. He wasn’t quite the whiz at math he had been before the accident, but otherwise he was his old self. He got a good job, married, had children, and is now a grandfather. But things don’t always go so well. People regularly awake from comas with serious and permanent brain damage or don’t awake from them at all.

  Vegetative State