A rising sense of dread heralds the new morning for our thinking man, who first considers the shotgun leaning by the door before turning to the coffeemaker — deciding that maybe tomorrow is the day.
For the late American novelist David Foster Wallace, that doomsday came Sept. 12, 2008. After suffering for years from major depression, one of the greatest and most influential writers in a generation succumbed to illness with a hangman’s rope in the garage. In death, Wallace joined a pantheon of notable artists and thinkers plagued by mental health disorders such as depression, bipolar disorder, and schizophrenia, among other ailments.
Indeed, society has long associated higher intelligence and creative thinking with mental illnesses ranging from the slight to the severe. Affecting some 2.5 percent of the U.S. population, bipolar disorder alone has touched many of our greatest achievers, including Vincent Van Gogh, Buzz Aldrin, Emily Dickinson, Ernest Hemingway, and Jackson Pollock to name just a handful. And although lacking a modern diagnosis, surely Virginia Woolf — who drowned herself in 1941 — fit the type.
Like the Sword of Damocles, higher intelligence may in some ways curse its beneficiaries. Aside from the usual desire to self-medicate, smarter people tend to drink alcohol and do drugs more than average — perhaps seeking to drench a burning sense of curiosity described by the Savanna-IQ Interaction Hypothesis. Long before the Agricultural Revolution brought alcohol to humankind, life on the African savannah during the Pleistocene helped design the modern mind. “The human brain has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment,” evolutionary psychologist Satoshi Kanazawa, of the London School of Economics, says of his theory.
In modern life, the opportunity to imbibe — or to otherwise ingest mind-altering substances — presents an “evolutionarily novel” situation explored more readily by the smarter, bolder ones among us. In fact, the correlation is so strong scientists say the inverse is true: People of lower intelligence are the least likely to drink or use drugs. Now, scientists have identified a biomolecular connection between curiosity as a trait and intelligence in general, as evidenced by a 2009 study in Neuron from researchers at the University of Toronto and the Samuel Lunenfeld Research Institute of Mount Sinai Hospital. Specifically, the neuronal calcium sensor-1 protein was associated in a mouse model with spatial memory and curiosity. Interestingly, that same protein has been linked in humans to bipolar disorder and schizophrenia.
Other research supporting a link between intelligence and mental health problems shows bipolar disorder may be four times as common among young adults who’d earned straight-A’s in school. Though long suspected, evidence for this connection was found by researchers at King’s College London, in a collaboration with the Karolinska Institutet in Sweden by comparing Swedish national school records to diagnoses for the disorder. “We found that achieving an A grade is associated with increased risk for bipolar disorder, particularly in humanities and to a lesser extent in science subjects,” lead researcher James MacCabe, wrote in a study published in the British Journal of Psychiatry. “These findings provide support for the hypothesis that exceptional intellectual ability is associated with bipolar disorder.”
Perhaps not surpisingly, the correlation between A grades and bipolar disorder was strongest among students excelling in music and language, supporting popular notions about writers and artists with regard to mental health. A similar study from Jari Tiihonen at the University of Kuopio in Finland also supports the link, although with arithmetic as a correlative for IQ. In mining data on Finnish military conscripts, the Finnish researchers found an almost unbelievably high correlation between high-scorers and those who later received bipolar diagnoses — 12-fold.
“The finding of an association between progressively increasing risk of bipolar disorder and high arithmetic intellectual performance is rather surprising,” Tiihonen wrote, explaining the arithmetic test requires not only mathematical skill but rapid information-processing for the purpose of successfully completing the timed exam. High scorers with such rapid processing power may also share a tendency to experience mania, a state of high focus and psychomotor activity. Along with bequesting humanity with advanced arithmetical or psychomotor performance, past generations may have also left us with a heightened risk for bipolar’s ups and downs.
Although some studies have shown no connection, more than 30 academic papers support a link between intelligence and bipolar disorder — among related illnesses — as researchers continue to experiment with mouse models and proteins, and to mine databases in search of what's missing. Soon, science may give us improved medicines to treat our maladaptive maladies of the mind. But at what cost to society? Known for his mercurial moods and heavy substance abuse, the late "Gonzo" journalist Hunter S. Thompson once insisted he’d have it no other way. “Without the booze and drugs," he said, "I’d have the mind of a third-rate accountant."
Correction: An earlier version of this article mispelled bipolar disorder. It has since been corrected.