Research Summaries: Childhood IQ and risk of bipolar disorder in adulthood: prospective birth cohort study
Today’s research summary focuses on an article [pdf] that throws some light on the oft debated question of the association between intelligence, creativity and mental illness.
- It has been hypothesized that various mental illnesses like Bipolar disorder, Schizophrenia etc persist in the gene pool because they are associated with some positive mechanisms that also confer survival or mating benefits, either to the patients or their close relatives. One such mechanism is thought to be apophenia (ability to see patterns, sometimes when there are none:-) ) , which is related to divergent thinking, imagination and creativity; another such mechanism is thought to be intelligence or the ability to solve complex adaptive problems flexibly.
- One method to settle the debate is correlational in nature. Sweden maintains rich and exhaustive data about its citizens. Mining data form the Swedish population registries, it was found that bipolar patients, as well as their relatives, were more likely to be in creative professions; and that bipolar traits may be associated with leadership qualities.
- Another method is to look at twins, one of which has the bipolar disorder, while the other hasn’t; and it was found that the other twin had high scores on sociability and verbal fluency; hinting that these may be linked to the bipolar proband.
- Yet another method is to look at longitudinal studies like the Dunedin studies, which track a child cohort since birth or early age and track them over time. The Dunedin studies found that low childhood IQ was associated with Schizophrenia spectrum disorder, depression an anxiety in adulthood; but high IQ was associated with mania in adulthood.
- The authors of this study used a longitudinal study design, analyzing the results of ALSPAC, a large UK birth cohort. This cohort consist of about 15,500 participation, but after all the dropout etc only about 2000 subjects results were part of the study results.
- This study focused on association of childhood IQ (which is an imperfect measure of true intelligence) with propensity for bipolar disorder in young adulthood. This study did not look at creativity and did not look at actual occurrence of bipolar disorder, thus all the results should not be extrapolated wildly.
- Childhood IQ at age 8 was measured using WISC-III and separate verbal and performance IQ as well as Full IQ scores were used in analysis. Propensity towards bipolar was measured using HCL-32 (hypo-mania checklist) which consist of 32 yes/no answers to statements like ‘I am more easily distracted’ when in a state of ‘high’ not associated with drug use. Only 28 items from this checklist were used. This was administered at ages 22-23 years.
- Childhood IQ was indeed associated with higher scores on HCL-32. The scores on HCL-32 were converted into percentile scores. Those subjects, who were in the lowest decile of HCL-32, or alternately had the lowest risk for later bipolar, had IQ scores that were 10 points on average lower than those subjects who were in the highest decile of HCL32 (had the highest bipolar risk).
- The IQ scores were also made categorical. Looking at data from another way, those who had the lowest verbal IQ scores (were in the ‘extremely low’ of VIQ) had on an average 7.1 points less score on HCL-32 than the ‘average’ VIQ group. The ‘ Very superior’ VIA group had scores 1.83 points higher than ‘average’ IQ group.
- As the age at which, HCL-32 was administered, not many people have the first manic/ depressive episode; so it might be capturing risk towards bipolar rather than actual incidence. Verbal fluency seems a more stronger predictor of bipolar risk than intelligence per se.
- As per my views, Bipolar pro-band may have more to do with creativity than intelligence and if future studies could operationalise and measure childhood creativity and look at later risk or occurrence of bipolar disorder, than that will settle the debate to an extent. Also important to remember that intelligence and creativity though correlated are different, with one perhaps requiring a threshold of intelligence to be creative.
- Lastly, if you are intelligent or creative, don’t fear, the risks seem to be too small and other factors like stress play a much more important role in triggering an illness. And even when triggered, it can be managed well!
If you liked the study and want to dig deeper, the full text article [pdf] is online.
I have Obstructive Sleep Apnea (OSA). I am also bipolar.
Now which of the above statements shocked/ surprised you more? If I am guessing correctly the latter statement about my being bipolar came across as more of a shock/ surprise/ concern. Now what does that say about your own reactions to mental illness and your own involvement in perpetuating the stigma against mental illness?
Both of the above are chronic diseases to an extent. My OSA (snoring in popular parlance) cannot be treated by surgery, so the only viable option I have is to use a CPAP machine while sleeping to get a good night’s sleep. Bipolar disorder as we all know can only be contained, and I take my medicines regularly to ensure that there are no relapse into either a manic or a depressive episode.
Both, if un-diagnosed and untreated can cause havoc. OSA which was un-diagnosed/ untreated for about a couple of years or so in my case led to excessive daytime drowsiness, less alertness and lowered productively etc; if untreated OSA can cause increased risk of injury to self and others while driving as you may actually get into micro sleeps while driving. Even if not that dramatic, on a daily basis the quality of your sleep and waking life can become very diminished. The downsides of having a manic or depressive episodes are well known- at least to readers of this blog. However, what may be less well known is that even in the throes of psychotic extremes, the risk to others from violence by bipolar people is very little and if anything they may be subjected to violence than otherwise.
When treated, that is when I use my CPAP machine regularly I have no problems at all due to my OSA either in my work life or in my personal life – I am as refreshed in morning as ever. Rather I believe I might be getting better sleep than the average person. When treated, that is when I regularly use medicine, and take other precautions like having regular sleep cycles etc for my bipolar, I am totally episode free- rather I believe I have an advantage when it comes to managing my energy and mood.
However, given all the above, which disclosure do you think has drastically lowered my chances of employment (if I was seeking employment, which I am thankfully not:-)); which disclosure would have led to discrimination in the workplace or at least got me some amused and funny looks? About which of these are my friends and acquaintances likely to gossip more? Why as a society we are still not that accepting of mental illness and stigmatize those who have it?
Some immediate consequences I can think of:
- readers of The Mouse Trap will no longer take my interest in psychology as non-partisan. They will think of me as being interested in psychology only due to my being bipolar (to set the record straight I became interested in psychology in 1996 during my IIT delhi days, while my first episode happened while I worked with Hughes in 2001). Also when I take a position like association of biploar with creativity, I will be considered biased; however nobody will say that a ‘normal’ person advocating otherwise is biased due to his being ‘normal’.
- Some will start to see signs of craziness in my old/ new posts and wonder whether when I was writing them I was in a normal frame of mind or episodic. Its usually my style to try and combine seemingly disparate research ideas and that is especially prone to this analysis.
- I will start getting sympathy, but like anyone living with say OSA or diabetes etc I think one should just ignore the fact about my being bipolar and not let it redefine my relationship with you. I am much more than a person with bipolar or OSA, and I prefer it that way.
- there will be some embarrassment for my near and dear ones.
Why did I not disclose for so many years?
- because I feared discrimination (and funny looks) at the workplace. It might have been imaginary but I was not strong enough to experiment. Now that I am self employed the stakes are much lower and I don’t care.
- I myself was grappling with my being bipolar. For initial some years it was hard to accept; later I struggled with accepting medication as necessary ; but now for quite some years I am at peace and thankfully episode free.
- As I believe it never affected adversely my performance at work , I did not deemed it necessary to inform my employers etc as I thought ,and still think, its none of their business.
Why did I decide to disclose publicly about this?
- I have no delusions (pun intended) that I am Deepika Padukone that my talking about a mental health issue is going to raise awareness drastically; still I want to do my bit to fight stigma and the journey starts with oneself. I had a decent career in software despite my being biploar and being biploar hasn’t stopped me from taking risks and experimenting with a second career; hopefully that can inspire or provide mental support to a person or two.
- Some immediate triggers- a mouse trap reader on facebook privately messaged me asking if I only have theoretical knowledge about psychosis etc or if I had some personal experiences too. I think it was a legitimate question that deserves a legitimate answer.
- Another immediate trigger- I came across a tweet by https://twitter.com/akhileshlinky about his year end ‘confession’ about being bipolar and I though heck why not ‘come out’ yourself.
- but really, it doesn’t matter to me one way or other – the only upside of sharing more publicly is that it can help combat stigma.
What I expect from you?
- don’t define me exclusively as being biploar.
- reflect on your own attitudes about mental illness and try to overcome that implicit bias
- resist discrimination and stigma
Lastly, thanks are due to my family and friends who have been prone to this ‘secret’ over the years and who have provided the necessary support and encouragement.
S. Nassir Ghaemi, in his book, A First Rate Madness: Uncovering the links between Leadership and Mental Illness, makes a case for the fact that while ‘normal’ leaders are good in times of stability and peace; in times of crisis, mentally ill or mentally abnormal people make for better leaders.
He does this via historical analysis of leaders like Gandhi, Martin Luther King jr, Franklin D. Roosevelt, Winston Churchill, Abraham Lincoln etc. Some of these leaders he classifies as being predominantly depressive, others as manic while the rest as being of bipolar proclivity. In the book he writes:
The depressed person is mired in the past; the manic person is obsessed with the future. Both destroy the present in the process.
He lists four traits that distinguish a manic/depressive leader from other normal leaders: Empathy, Resilience, Creativity and Realism! I can easily map these to the ABCD dimensions: empathy is an Affective trait (the ability to feel emotions), resilience is more about Behaviors (bouncing back from failures), creativity is related to Cognition (ability to think in a divergent manner) while realism can be linked to Desire/Dynamism (do we do realistic assessments).
He claims, and I find that claim very attractive and true, that depressive people typically are better at empathy and realism, that is, they have heightened empathy and realism as compared to the normal population; in a similar vein, manic people are typically better at creativity and resilience than the normal population.
If one views depression and mania as somewhat opposed to each other. at least on on some dimensions, it goes without saying that depressive people may be less creative (they are typically stuck in ruts)/resilient (they often cant cope and sometime stake the extreme step of suicide); similarly, in a manic phase, people may be less realistic (may even become psychotic losing touch with reality)/ empathetic (may not be able to get inside the head of others).
While a depressive or manic phase may be debilitating, the relatively ‘normal’/symptom free period may confer advantages on depressives, manics or bipolars by making them leverage their resilience, creativity, realism and empathy, especially to tide over crisis.
Why should it be the case that in normal periods a ‘normal’ leader may help, but in a crisis only an ‘abnormal’ leader may be able to rise to the occasion? The answer lies in evolution and genetic diversity. Consider moths that are generally gray in color, but some are darker (closer to black) while some others lighter (white in color) . The majority gray moths are the ‘normal’ moths, while the minority black and white are abnormal ones. Now these moths are exquisitely adapted to their environments, and typically gray moths will flourish. However if the area has suddenly become polluted such that darker color moths are now less easier to detect than the gray moths by the predators, then dark moths will thrive at the cost of light moths.
A similar analogy can be applied to humans. Normal leaders are adapted to stable conditions; while in times of crisis, more atypical brains may suffer greater advantage.
So next time you select a leader, be mindful of whether its a change/crisis situation or a stable situation; if a crisis/ change situation, you may do well to do some reverse discrimination and select a mentally ill/ abnormal person as a leader!!
In a study that could have potentially far-reaching effects for the Bipolar research and treatment, Dr Colleen and her group have reported on a mouse model of bipolar disorder.
The association between circadian rhythms and bipolarity is well established and a bipolar episode is characterized with disruptions in daily sleeping, eating rhythms etc. Till now the biological basis of this was not clear.
In this study, mice with Clock gene knocked out were tested on a number of measures of bipolairty and it was found that these mice lacking the Clock gene, which is essential for proper circadian rhythms, suffered from human manic like symptoms. Moreover treating these bipolar mice with lithium resulted in the subsiding of symptoms.
The study included putting the mutant mice through a series of tests, during which they displayed hyperactivity, decreased sleep, decreased anxiety levels, a greater willingness to engage in “risky” activities, lower levels of depression-like behavior and increased sensitivity to the rewarding effects of substances such as cocaine and sugar.
“These behaviors correlate with the sense of euphoria and mania that bipolar patients experience,” said Dr. McClung. “In addition, there is a very high co-morbidity between drug usage and bipolar disorder, especially when patients are in the manic state.”
During the study, lithium was given to the mutant mice. Lithium, a mood-stabilizing medication, is most commonly used in humans to treat bipolar patients. Once treated with the drug on a regular basis, the majority of the study’s mice reverted back to normal behavioral patterns, as do humans.
The clock gene is expressed widely in the human brain, but the focus till now was only on the area called suprachiasmatic nucleus. In this study the area of brain associated with reward learning, VTA/ Striatum etc was studied and expressing the clock gene there in KO mice resulted in subsiding of symptoms.
The researchers also injected a functional Clock gene protein – basically giving the mice their Clock gene back – into a specific region of the brain that controls reward functions and where dopamine cells are located. Dopamine is a neurotransmitter associated with the “pleasure system” of the brain and is released by naturally rewarding experiences such as food, sex and the use of certain drugs. This also resulted in the mice going back to normal behaviors.
This is an exciting news as it makes a mice model for Bipolairty readily available and would help in clinical testing of new anti psychotics and mood stabilizers.