Creativity and psychopathology
Abstract: The Mad Genius is a recurring stereotype of contemporary cultural expression. However, starting with Lombroso’s investigation of genius and madness in 1888, recent decades have seen an increasing number of empirical studies suggesting that there really is an association between creativity and psychopathology. Still, taken together, the empirical support is unconvincing - largely due to a heavy reliance on biographical data and small cohorts. The primary aim of this thesis is therefore to investigate the question of a possible association between creativity and psychopathology using large scale population based epidemiological methods. The proposed association of creativity and psychopathology has often been placed in an evolutionary context, where the burden of psychopathology is compensated for by the advantage of increased creativity. The secondary aim of this thesis is to elucidate if a putative association between creativity and psychopathology may be mediated through genetic factors under positive selection. In our first study (study I), based on Swedish national registries, the likelihood of holding a creative profession (artistic and scientific occupations) in individuals (n~300 000) with schizophrenia, bipolar disorder or unipolar depression and their healthy relatives was compared to that of controls. Results demonstrated that individuals with bipolar disorder and healthy siblings of people with schizophrenia or bipolar disorder are overrepresented in creative professions. We followed up these findings in study II using a dataset with a considerably larger sample of patients (n~1 200 000) to survey other psychiatric diagnoses and to validate previous findings. Study IV investigated the notion that bipolar disorder is common in prominent historical leaders, e.g., Winston Churchill, Abraham Lincoln, and Napoleon Bonaparte. Results showed that individuals with bipolar disorder without comorbidity and their healthy siblings were overrepresented in the highest strata of officer suitability, a rating of leadership potential. The siblings were also overrepresented in executive professions, specifically in the subgroup of political professions. In study III we addressed the evolutionary framework by investigating the fertility of individuals with psychiatric disorders and their healthy siblings. A total of ~ 2.3 million individuals were included. With the exception of women with depression, patients had significantly fewer children than the general population. The evolutionary hypothesis was further investigated in study V , where we systematically reviewed the genetics of creativity and estimated the heritability of creativity in two new original studies. Results support a genetic component in creativity, and for the first time suggest that this is contingent on sex. In conclusion, this thesis provides support for a familial cosegregation of both schizophrenia and bipolar disorder with creativity, and suggests that this may be mediated through a genetic mechanism. Results do not support, however, that any psychiatric disorder per se is under positive selection.
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