I'm pointing out that tulpas are basically a self-inflicted case of what the medical profession calls dissociative identity disorder and that it has significant mental costs.

Taylor et al. claim that although people who exhibit the illusion of independent agency do score higher than the population norm on a screening test of dissociative symptoms, the profile on the most diagnostic items is different from DID patients, and scores on the test do not predict IIA:

The writers also scored higher than general population norms on the Dissociative Experiences Scale. The mean score across all 28 items on the DES in our sample of writers was 18.52 (SO = 16.07), ranging from a minimum of 1.43 to a maximum of 42.14. This mean is significantly higher from the average DES score of 7.8 found in a general population sample of 415 [27], ((48) = 8.05, p < .001.

In fact, the writers' scores are closer to the average DES score for a sample of 61 schizophrenics (schizophrenic M = 17.7) [27]. Seven of the writers scored at or above 30, a commonly used cutoff for "normal scores" [29]. There was no difference between men's and women's overall DES scores in our sample, a finding consistent with results found in other studies of normal populations [26].

With these comparisons, our goal is to highlight the unusually high scores for our writers, not to suggest that they were psychologically unhealthy. Although scores of 30 or above are more common among people with dissociative disorders (such as Dissociative Identity Disorder), scoring in this range does not guarantee that the person has a dissociative disorder, nor does it constitute a diagnosis of a dissociative disorder [27,29]. Looking at the different subscales of the DES, it is clear that our writers deviated from the norm mainly on items related to the absorption and changeability factor of the DES. Average scores on this subscale (M = 26.22, SD = 14.45) were significantly different from scores on the two subscales that are particularly diagnostic for dissociative disorders: derealization and depersonalization subscale (At = 7.84, SD = 7.39) and the amnestic experiences subscale (M = 6.80, SD = 8.30), F(l,48) = 112.49, p < ,001. These latter two subscales did not differ from each other, F(l, 48) = ,656, p = .42. Seventeen writers scored above 30 on the absorption and changeability scale, whereas only one writer scored above 30 on the derealization and depersonalization scale and only one writer (a different participant) scored above 30 on the amnestic experiences scale.

A regression analysis using the IRI subscales (fantasy, empathic concern, perspective taking, and personal distress) and the DES subscales (absorption and changeability, arnnestic experiences, and derealization and depersonalization) to predict overall IIA was run. The overall model was not significant r^2 = .22, F(7, 41) = 1.63, p = .15. However, writers who had higher IIA scores scored higher on the fantasy suhscale of IRI, b = .333, t(48) = 2.04, p < .05 andmarginally lower on the empathic concern subscale, b = -.351, t(48) = -1.82, p < .10 (all betas are standardized). Because not all of the items on the DES are included in one of the three subscales, we also ran a regression model predicting overall IIA from the mean score across DES items. Neither the r^2 nor the standardized beta for total DES scores was significant in this analysis.