The utility of the Structured Inventory of Malingered Symptomatology for distinguishing individuals with Dissociative Identity Disorder (DID) from DID simulators and healthy controls

Figures & data

Figure 1. DID = dissociative identity disorder; SIM = simulators; HC = healthy controls; SIMS = Structured Inventory of Malingered Symptoms; NI = neurological impairment; AF = affective disorders; P = psychosis; LI = low intelligence; AM = Amnesia

Error bars represent the standard deviation for each subscale.

Table 1. DES and SIMS descriptives for total score and subscales

	DID	SIM	HC
DES Mean^1	43.76(17.92)	15.63(15.09)	4.61(3.67)
SIMS Score	23.59(11.03)	44.38(13.37)	9.89(4.58)
Neurological Impairment	4.54(3.14)	8.90(4.18)	.80(.96)
Affective Disorders	7.05(2.20)	9.39(2.27)	3.34(1.45)
Psychosis	3.05(3.05)	9.47(4.49)	.41(.61)
Low Intelligence	2.95(2.65)	4.91(3.12)	4.14(2.65)
Amnesia	6.00(3.82)	11.57(3.57)	1.20(1.12)

Note. DID = dissociative identity disorder; SIM = simulators; HC = healthy controls; DES = Dissociative Experiences Scale; SIMS = Structured Inventory of Malingered Symptoms.

¹All groups completed the DES reflective of their experiences without simulation of DID.

Table 2. Utility statistics for SIMS total score based on DID status

	Actual status
Predicted group status	Simulator	DID
Simulator (n)	74	54
DID (n)	3	9
Sensitivity	.96
Specificity	.14
PPV	.58
NPV	.75
ODP	.59

Note. n = 140. DID = dissociative identity disorder; PPV = positive predictive value; NPV = negative predictive value; ODP = overall diagnostic power. Base rate of DID = 54%