Is there a connection between manic depression and high intelligence? A new study seems to have found one, yet has also produced puzzling, seemingly contradictory data.
A team of researchers led by Catharine Gale, Ph.D examined a very large cohort of subjects to find whether this condition, also known as bipolar disorder, is more likely in unusually intelligent people. The data they collected does support the contention that very high intelligence and manic depression are indeed connected.
Our culture is primed to believe in a link between madness and high intelligence. Movies and novels often feature stories of brilliant but mentally ill artists, musicians and deep thinkers.
The "crazy genius" behind innovations in art or science has become something of a cliche, yet a resonant one, as there is some basis in actuality for this myth.
Mathematicians celebrate the work of Kurt Godel while philosophers quote Ludwig Wittgenstein, and both of these geniuses of logic struggled with very serious mental illnesses. Russell Crowe convincingly portrayed Nobel Laureate John Nash in "A Beautiful Mind" as a mathematically gifted paranoiac who hallucinated conspiracies.
Philosophers ponder whether the intense genius of Friederich Nietzche can be separated from his evident madness. Jazz musicians lionize innovators such as Charlie Parker and Thelonius Monk, both of whom struggled with serious psychological distress.
Rockers are perennially fascinated by mentally ill psychedelic rock pioneers such as Brian Wilson of the Beach Boys and "crazy diamond" Syd Barrett of Pink Floyd.
It is not hard to believe that brilliant people might more likely to be mentally ill. What does science say? Can we measure whether or not high intelligence is a risk factor or predisposes individuals to mental illness?
Dr.Gale and colleagues frame the problem thusly:
"The idea that genius and madness are linked dates back at least as far as the ancient Greeks. Anecdotal and biographical reports suggest that the extreme mood swings of elation and despair characteristic of bipolar disorder (previously known as manic depression) are more common in individuals with exceptional cognitive and creative ability."
The team examined 1,049,607 males to try to understand what connections may exist between intelligence and bipolar disorder. The researchers were able to access records with data about the intelligence assessments of these individuals as well as any history of hospitilization for bipolar disorder and other mental illnesses.
The experience of going from one "pole" to the other seems to be made of fantastically complicated shifts of brain chemistry. Some of the brain's 100 billion neurons modify the electrochemical signals they emit, which produces a cascade of altered chemistry. This results in a dramatic difference in how such a person feels, thinks, and acts.
Bipolar disorder, or manic depression, involves a poorly-understood shifting of consciousness, behavior, and brain chemistry from overexcited, higher-energy "up" states to a subdued, negative, low energy phase.
In the manic phase, people can display exuberance, be outgoing, intense, jumpy or prone to rapid shifting from topic to topic. Some higher-functioning persons with the bipolar label may indeed display productivity and focus in the manic phase, though others may be too distracted and fidgety, or worse engage in risky activities.
The depressive phase can manifest as withdrawal, sadness, weakness, irritability, poor sleep, feelings of hopeless, difficulty focusing and negative fixations. Unlike a person diagnosed with depression, the bipolar at some point cycles back to the manic phase again.
Gale and colleagues analyzed over one million results of intelligence tests and medical records to see what connection may exist between very high intelligence and manic depression. They found that risk for bipolar disorder was higher than normal among men assessed as having the highest intelligence.
The results of these researchers do seem to support the idea that high intelligence may very well increase the likelihood of one particular form of mental illness. However, their data showed this connection only in the minority of men in the study who were labeled as bipolar but were not also diagnosed with another psychiatric disorder.
Interestingly, individuals measured as having the lowest intelligence also had enhanced risk for bipolar disorder. While this may seem contradictory, the researchers note that there are previous findings that two different categories of schoolboys, those with very high and with very low school grades, are both at greater risk for developing bipolar disorder as adults.
Gale and her team summarize the meaning of their work thusly: "These findings based on over a million men provide partial support for the belief that exceptional intelligence and a particular form of ‘madness’ are linked."
The researchers venture that their data is consistent with the biographies about manic-depressive individuals also having "exceptional literary or scientific creativity".
The meaning of all of this is unclear. The study examined men only, a serious limitation. The finding that two groups of men who were assessed as either high and low intelligence both had elevated risk for bipolar disorder is interesting but perhaps contradictory. There is also controversy about how well intelligence tests measure intelligence.
Science will have much more to say about the curious relationship between intelligence and mental illness in coming years. Whether the link is real, and what role is played by diet, environment, upbringing, stress, genes or drugs and alcohol remains to be discovered. Whatever the scientific verdict, the popular fascination with the troubled psychological states of geniuses will no doubt remain.