Researchers conducting one such study of Swedish teenagers discovered straight-A students were four times more likely to develop bipolar disorder, a mental illness marked by alternating moods of elation and depression, illustrating a correlation between intelligence and higher instances of mental illness. As the study subjects' emotional state transitioned from low to high, there was evidence of increased activity in the frontal lobe of the brain. This area is known for regulating creativity.
The study was expanded in 2012 to include more than 1 million participants, and researchers reported a link between artists, authors and scientists and the propensity to develop mental illness. Not only bipolar disorder, but a whole suite of mental illnesses, from drug abuse to anorexia nervosa and depression. A single gene, known as DARPP-32, is suspected to cause the link between intelligence and mental illness. A study found that people with schizophrenia were more likely to have the version of DARPP-32 that boosted performance on tasks involving thinking and filtering of information [source: National Institute of Mental Health].
Studies such as these could affect the way mental illness is understood and treated. If a scientist grapples with a bipolar disorder, but relies on the moments of brilliance that bubble up when depression transitions into mania, what is the best treatment? A medication that makes the majority of his days more bearable (and potentially keeps him from self-harm) or a behavior modification program that allows for feverish, singular obsessions? In some cases, a tandem approach is best, combining drug therapy with behavioral therapy to decrease stressful triggers or cognitive therapy to change thought patterns.
While some psychologists and researchers claim there's an "upside" to mental illness, one that produces bouts of creative and productive thinking, there is a clear downside, too. Untreated bipolar disorder, for example, can lead to substance abuse or suicide. If mental illness represents a classic case of risk versus benefits, it also is an intensely personal equation [source: Science Daily].
Of course, there's also the matter of opposing evidence. Some studies have shown no difference in IQ levels between those with bipolar disorder and those without it. Others indicate that greater acumen is a protective factor against the most psychotic illnesses and that low intellect is associated with developing, for example, severe bipolar disorder. A great deal of research is being carried out in this area, with the aim of fully understanding how this illness is linked to intelligence [source: Collingwood].