Creativity in bipolar disorder: a systematic review

Abstract Introduction Based on studies of the biographies of artists and on research in which modern diagnostic criteria were applied, it has been suggested that there is a relationship between bipolar disorder (BD) and creativity. Objective: To investigate the relationship between BD and creativity and whether creative capacity varies depending on mood state. Method We conducted a systematic search of the scientific literature indexed on the PubMed, ISI Web of Science, PsycINFO, and SciELO databases using the terms “bipolar” OR “bipolar disorder” OR “mania” OR “manic” AND “creativ*”. Original studies were selected that investigated samples of at least ten patients with BD using at least one psychometric instrument to assess creativity. Results Twelve articles met the selection criteria. The results of comparisons of BD patients with control groups without BD were heterogeneous. BD was not associated with higher levels of creativity than other mental disorders. When comparing BD phases, depression was associated with worse performance on creativity tests and patients in mania (or hypomania) were not distinguished from euthymia patients. Conclusion It was not possible to corroborate the hypothesis that individuals with BD are more creative than individuals without psychiatric diagnoses or than patients suffering from other mental disorders, which may be related to the cross-sectional rather than longitudinal designs of virtually all of the clinical studies.


Introduction
Bipolar disorder (BD) is a serious, chronic, and disabling mental disorder characterized by the occurrence of hypomanic or manic episodes and depressive episodes. 1 After the first episode of the disease, almost 90% of individuals experience at least one further episode throughout their lives. 2 Many individuals have progressive cognitive impairment. 3 Between 30 and 60% of BD patients have low psychosocial functioning. 4 Compared to the general population, BD patients have higher unemployment rates and lower income and, when employed, spend more time on sick leave. 5 BD is the mental disorder most associated with suicide. Approximately 40% of patients attempt suicide at least once in their lives. 6 The rate of completed suicides can be up to 58 times higher in BD patients than in the general population and these suicides are violent in more than 90% of cases. 7 Despite the severity of BD, many authors suggest that there are positive aspects to the disease. Authors such as psychologist Kay R. Jamison and psychiatrists Nancy Andreasen and Arnold K. Ludwig believe that there is a relationship between BD and creativity, based on studies they have conducted of the biographies of eminently creative artists and writers. [8][9][10][11] Moreover, studies using modern diagnostic criteria have found higher prevalence of depressive and manic episodes in artists and writers, compared to the general population. 12 There are many definitions of creativity, but none are universally accepted. 13 Based on the "Handbook of Creativity," 14 the most mentioned publication on the topic, creativity is the ability to combine talent, process, and environment to produce something that is perceived as original and, at the same time, useful in the context. 15 Creativity is a multidimensional skill demonstrated by a person, through a process, which creates a product, in response to the environment in which it operates. [16][17][18] Studies of the creative person seek to evaluate individual characteristics that favor creativity, such as intrinsic motivation, openness to experience, variety of interests, and autonomy. 17 Creative people stand out for their perception of problems, fluency of ideas, mental flexibility, divergent thinking, ability to redefine familiar objects and concepts, positive mood, complex temperament, and self-confidence. 19 Creativity can be assessed using personality scales, derived from the study of common characteristics of people already considered creative, or by researching previous behaviors that may reflect creative potential and accomplishments. 17 The following instruments, respectively, are examples of these two possibilities: the Adjective Check List Creative Personality Scale (ACL-CPS) 20 and the Creativity Achievement Questionnaires (CAQ). 21 People can also be assessed for creativity in a specific field of activity, such as in the fields of linguistics, logic, arts, or sciences. 22 The specific area most investigated is that of artistic creativity, most commonly using the Barron-Welsh Art Scale (BWAS). 23,24 This scale comprises figures of different degrees of complexity and varying levels of symmetry. Subjects indicate whether they like or dislike each image. Preference for high complexity and asymmetry is considered an indicator of creativity. 25 Studies of the creative process seek to understand the mental mechanism involved when an individual performs a creative activity. 17 This aspect of creativity can be evaluated based on the results of tests of divergent thinking and remote association. These tests use criteria based on originality, usefulness, and rarity of responses. Divergent thinking tests are more widely used and the Torrance Tests of Creative Thinking (TTCT) is considered the gold standard. 26 Creative product reviews focus on something a person does or expresses, such as poems, music, drawings, or answers to an open question. Just as a person can be evaluated in a specific field of activity, their creative product can also be classified in the same way. 27 This aspect is usually analyzed according to the opinion of experts, evaluation of teachers and peers, eminence, and self-reported creative activities and achievements. 18 The Lifetime Creativity Scales (LCS) 28 is an example of an instrument that evaluates the creative product, measuring the quantity and quality of a person's involvement in creative activities throughout adult life, both in free time, and at work.
Finally, assessments of the creative environment seek to find characteristics that induce or inhibit creativity.
The environment is rarely considered during evaluation of individual creativity. 27 The Virtual Team Creative Climate Measure (VTCC) 29 is an example of such an instrument, evaluating items such as acceptance of ideas, collaboration, commitment, and clarity of objectives, among others. 17 Research on creativity can result in many controversies, mainly because of weaknesses in the methodologies used. 27 The first problem resides in the concept of creativity. Few definitions are widely accepted and researchers often avoid using a definition. 17 The second problem is the proper choice of instruments for the research objectives. It is essential to distinguish between creative potential and creative achievements.
An instrument capable of predicting creative potential is very different from another that measures current levels of performance. 26 The format of studies constitutes a third problem. Although more difficult to accomplish, the most reliable form of research is longitudinal. 17 Longitudinal studies can evaluate the creative capacity of individuals who, for a variety of reasons, may not yet have achieved exceptional results. 30 Finally, the fourth problem is the tendency to investigate only one aspect of the concept of creativity, which is multidimensional.
Psychometric instruments generally only assess one of the four aspects of creativity -person, process, product, or environment -in isolation. 17 Since each instrument has its limitations, it is highly recommended to select a combination of instruments. 26 At least two systematic reviews 31,32 have studied the relationship between psychopathology and creativity. Thys et al. 31 found an association between suffering from a mental disorder, especially a mood disorder or a psychotic disorder, and being creative.
However, the studies included in this review were highly heterogeneous and most of them had important methodological limitations. In addition, their conclusions are based on a mere count of the number of articles that presented positive or negative results on whether a certain mental disorder was related to creativity. In contrast, Taylor 32 carried out a meta-analysis and was more rigorous in its selection of the original studies.
According to her results, there were more cases of mood disorders among individuals considered to be creative than among non-creative individuals. On the other hand, when individuals with mood disorders were compared with others without this diagnosis, no significant differences were found regarding the level of creativity. Neither of these two systematic reviews specifically addressed BD.
We conducted a systematic review of clinical studies that objectively assessed creativity in patients with BD in order to investigate the relationship between this mental disorder and creativity and whether creative capacity varies depending on BD mood state, i.e., mania, depression, or euthymia.

Method
We sought studies in which patients with BD were compared in terms of creative ability with healthy controls or with patients with other mental disorders.
We also sought studies with samples of patients with BD in which the different states of the diseasemania, depression, mixed state, and euthymia -were compared.
Up to January of 2021, we carried out a systematic search of the scientific literature indexed on the PubMed, ISI Web of Science, PsycINFO, and SciELO databases using the terms "bipolar" OR "bipolar disorder" OR "mania" OR "manic" AND "creativ*".
There was no restriction on the date of publication.
Articles that met the following criteria were selected: original studies, published in Portuguese or English, with samples of at least 10 BD patients, and using at least one psychometric instrument to assess creativity.
The diagnosis of BD should be made using operational criteria. Letters, editorials, review articles, case studies, and biographical studies were excluded. Two of the authors carried out each step of this search independently, compared their results and reached a consensus. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart to illustrate the search strategy adopted to select the articles. 33

Results
We found 165 results in the PubMed database, 179 in ISI Web of Science, 222 in PsycINFO, and only five in SciELO, making a total of 571 articles. After removing the duplicates, 271 articles remained, 224 of which were excluded during reading of titles and abstracts.
After reading the remaining 47 articles in full, some were excluded: nine because the subjects were not diagnosed with BD; nine in which there was no objective evaluation of creativity; six because they were letters or editorials; six that were case studies or biographical studies; three in which the authors evaluated aspects related to creativity, but not creativity itself; and one review article. We were unable to access one article, even after trying to contact the authors directly. Thus, 12 articles were selected according to our criteria. [34][35][36][37][38][39][40][41][42][43][44][45] Our systematic search method is illustrated as a flowchart in Figure 1.  the TTCT-Figural (TTCT-F) and TTCT-Verbal (TTCT-V) versions, 42,68 and the Creative Thinking Task -designed specifically for the study, 44 were each used in only one study. Only one study evaluated the creative product, 45 using the LCS. 28 The creative environment was not evaluated in any studies.    or to patients with ADHD. 43 However, the performance of patients with BD was inferior to a group consisting of patients with cyclothymia and their families. 45 Four of the 12 studies compared different mood states with each other 36,37,40,41 (Table 3). All four of these included a group of patients in mania and a group of patients in depression; two also included a group of patients in mixed states, 36,37 and one had a group of patients in euthymia. 37 The severity of affective symptoms was assessed, but only to identify mood states, that is, mania, depression, or euthymia. None of the four studies investigated a possible correlation between the severity of symptoms and the level of creativity.
In these four studies, patients in bipolar depression performed worse on assessments of creativity than patients in mania. 36,37,40,41 In one of these four studies, patients in bipolar depression also had lower results in the comparisons with patients in euthymic and mixed states. 37 Patients in mania (or hypomania) were more creative than patients in mixed states in two studies. 36,37 Finally, in one study, patients in mania (or hypomania) were not distinguished from euthymia patients. 37

Discussion
The objectives of this systematic review were to investigate the relationship between BD and creativity and whether creative capacity varies depending on mood state. According to the results found, it is not possible to say that BD patients are more creative than healthy controls or than patients with other mental disorders.
In the comparisons between the different stages of BD, we observed that patients in depression or in mixed states had the worst performances, however patients in mania did not perform better than patients in euthymia.
The conflicting results reflect the methodological weaknesses often found in research on creativity. 27 Most studies did not define the concept of creativity and none of them considered multidimensionality. Although they were investigating a multidimensional concept, no study evaluated more than two aspects of creativity, and the majority evaluated only one. The most studied aspects were the process and the person. Since the results were heterogeneous, it is not possible to say that BD patients are more creative in any of these aspects.
Humor and motivation are important elements for creativity. In the depressive phase of BD, most mental activity is inhibited. Patients often complain of slowness of thought, confusion, and an inability to concentrate.
They feel inadequate and useless. 69 Thus, it is to be expected that there would be a decrease in productivity and creativity. On the other hand, in hypomania, the increased speed of thoughts can contribute to creative production, increasing the number of thoughts and producing unique ideas and associations. 70 Due to the attenuated symptoms, it can be assumed that it is during hypomania that people with BD would obtain the greatest benefits from their creativity. In contrast, in mania, it is very common for patients to produce with reduced quality or to give up their creative tasks before completing them. 70 In this mood state, people with BD can easily be distracted by any stimuli and their thoughts can be accelerated, becoming disconnected and inconsistent with reality. 69 The results of the studies we found went against Since cyclothymia is an "attenuated" BD, it could count on some of the advantages of BD, such as creativity, without the most serious negative consequences.
When the different mood states of BD were compared, patients in depression were less creative, as expected, but because none of the studies separated patients in mania from those in hypomania, it was not possible to confirm whether the latter mood state is in fact associated with an increase in creativity.
Many creative individuals who suffer from BD consider emotional turbulence essential to their identities and worry that psychiatric treatment compromises their ability to create. 69 There are various ways in which the medications used to treat BD can alter characteristics important for creativity, such as motivation to achieve goals, disinhibition, novelty seeking, and the ability to associate ideas. 71 There is evidence that treatment of people with BD with lithium can decrease associative productivity 72,73 and artistic creativity. 74 Measures of memory and motor performance significantly improve when lithium is withdrawn and decrease when treatment is restarted. 73 Even if the patient is not an artist or an academic, creativity should be taken into account by clinicians. 71 Doctors should be aware of the side effects of medications on the creative process and, whenever possible, reduce doses. 69 Creativity depends on a set of mental operations applied to existing knowledge, through cognition. 75 Creative people stand out for their greater ability to organize their ideas effectively, selecting those that are useful and discarding the others. 76 To achieve this goal, the main cognitive skills involved in the creative process are attention, memory, and executive functions. It is the combination of these processes that makes a person able to maintain and manipulate information in working memory, suppress irrelevant information, and change strategies as needed. 77  There were no groups with only hypomanic patients.
There was also no uniform concept of creativity.

Disclosure
No conflicts of interest declared concerning the publication of this article.