First, the rate and intensity of psychopathological symptoms appear to be higher among eminent creators than in the general population (Ellis, 1926; Raskin, 1936). Although the differential depends on the specific definition used, a reasonable estimate is that highly creative individuals are about twice as likely to experience some mental disorder as otherwise comparable noncreative individuals (Ludwig, 1995). Depression seems to be the most common symptom, along with the correlates of alcoholism and suicide (Goertzel et al., 1978; Ludwig, 1990; Post, 1996).
Second, on average, the more eminent the creator, the higher is the expected rate and intensity of the psychopathological symptoms (Ludwig, 1995).
Third, the rate and intensity of symptoms varies according to the specific domain of creativity (Ludwig, 1992; Post, 1994). For example, psychopathology is higher among artistic creators than among scientific creators (Post, 1994; Raskin, 1936). Thus, according to one study, 87% of famous poets experienced psychopathology whereas only 28% of the eminent scientists did so, a figure close to the population baseline (Ludwig, 1995).
Fourth, those family lines that produce the most eminent creators also tend to be characterized by a higher rate and intensity of psychopathological symptoms (Jamison, 1993; Juda, 1949; Karlsson, 1970).
Hence, even though there is some evidence that the lifestyle of creative activity can have adverse consequences for mental health (Schaller, 1997), it remains the case that there may be a common genetic component to both creativity and psychopathology (Ludwig, 1995).
Psychiatric research. This type of evidence depends on the incidence of clinical diagnosis and therapeutic treatment in samples of contemporary creators. Hence, the research does not require retrospective analysis as in historiometric research, and the assessment of psychopathology reflects modern standards. In any case, psychiatric studies also seem to find higher rate and intensity of symptoms among distinguished creators, especially those engaged in artistic creativity (Andreasen and Canter, 1974; Jamison, 1989). Once more, depression, alcoholism and suicide appear to be the most common indicators. Furthermore, the evidence suggests that creativity and mental illness run in the same family lines (Andreasen, 1987; McNeil, 1971; Myerson and Boyle, 1941).
Psychometric research. Here, standard assessment instruments are applied to contemporary creators. The sampled creators either vary substantially in creative achievement or else they are compared to a control group of noncreative participants who are otherwise comparable. The psychometric measures include the Minnesota Multiphasic Personality Inventory (MMPI) and the Eysenck Personality Questionnaire (EPQ) (Gough, 1953). In general, highly creative individuals score above normal level on several dimensions associated with psychopathology (Barron, 1963). For instance, creativity is positively correlated with psychoticism scores on the EPQ (Eysenck, 1995, 1994). In addition, the higher the level of creativity displayed, the higher the scores tend to be on the clinical scales. Nonetheless, artistic creators still have more elevated scores than do scientific creators (Simonton, 2004).
The days of getting eminent creators to take the MMPI or EPQ are long gone, with the classic studies done in the 1950s and '60s. Eysenck's work is a research integration of work published much earlier. More recent work tends to focus on specific components, such as the research on latent inhibition discussed later. Also, the psychometric literature provides some unique empirical results that can shed some light on the specific nature of the relationship between creativity and psychopathology. The following two sets of findings stand out.
