Personality traits in established schizophrenia: aspects of usability and differences between patients and controls using the Swedish universities Scales of Personality

Figures & data

Table 1. Characteristics of patients and controls.

	Patients (n = 107)	Controls (n = 119)	P-value
Gender (n, women/men)	35/72	48/71	NS^a
Age (year)	41.9 (8.9)	43.1 (8.0)	NS^b
Education (year)	12.7 (3.0)	14.2 (2.8)	P < 0.001^b
WAIS verbal IQ	87.9 (20.8)	102.4 (15.9)	P < 0.001^b
GAF	48.8 (9.4)	85.8 (7.3)	P < 0.001^b
Diagnosis – schizophrenia (n)	82	NA
Diagnosis – schizoaffective disorder (n)	15	NA
Diagnosis – psychosis NOS (n)	10	NA
Age at onset of illness (year)	24.3 (5.0)	NA
SANS composite score	30.9 (21.6)	NA
SAPS composite score	11.2 (9.0)	NA
Medication (mg, CPZ-equivalents)	252.9 (233.8)	NA
Medication – no antipsychotics (n)	7	NA
Medication – 2nd gen antipsychotics (n)	47	NA
Medication – 1st gen antipsychotics (n)	46	NA
Medication – 1st and 2nd gen antipsychotics (n)	7	NA

NS: not significant; NA: not applicable; WAIS: Wechsler adult Intelligence Scales; IQ: intelligent quotient; GAF: Global Assessment of Functioning; SANS: Scale for the Assessment of Negative Symptoms; SAPS: Scale for the Assessment of Positive Symptoms; CPZ: chlorpromazine; gen: generation; NOS: not otherwise specified. All values in mean (standard deviation) except for distribution of gender, diagnosis and medication.

Missing data (patients/controls): Education (2/2), WAIS vocabulary (30/38), GAF (1/0), SANS (29), SAPS (29).

^aχ²-test. ^bUnpaired two-sided t-test.

Table 2. Swedish Scales of Personality (SSP) internal consistency data given as Cronbach’s alfa for psychotic patients (n = 107) and control subjects (n = 119). Data from the Swedish normative study (n = 741) and an Estonian study of healthy subjects (n = 529) is shown for comparison (11,25).

SSP scale	Patients	Controls	(11)	(25)
Neuroticism	0.82	0.89	–	–
Aggressiveness	0.62	0.71	–	–
Extraversion	0.54	0.46	–	–
Somatic trait anxiety	0.59	0.80	0.75	0.75
Psychic trait anxiety	0.79	0.86	0.82	0.82
Stress susceptibility	0.67	0.80	0.74	0.73
Lack of sssertiveness	0.75	0.77	0.78	0.64
Impulsiveness	0.70	0.69	0.73	0.62
Adventure seeking	0.81	0.84	0.84	0.80
Detachment	0.71	0.80	0.77	0.58
Social desirability	0.55	0.52	0.59	0.66
Embitterment	0.67	0.77	0.75	0.73
Trait irritability	0.73	0.78	0.78	0.85
Mistrust	0.78	0.84	0.78	0.76
Verbal trait aggression	0.78	0.71	0.74	0.78
Physical trait aggression	0.75	0.85	0.84	0.84

Table 3. Swedish universities Scales of Personality (SSP) raw scores (mean [standard deviation]) in patients with psychotic illness (Pat) and non-psychotic controls (Con). Data is shown by diagnosis (pat vs con) in all subjects, gender in all subjects, gender among patients and gender among controls. P-values stem from analyzes of covariance assessing diagnosis, gender and diagnosis * gender with age as a covariate.

		N	Age (year)	STA	PsTA	SS	LA	I	AS
ALL	Pat	107	41.93 (8.91)	2.06 (0.53)***	2.48 (0.65)***	2.51 (0.54)***	2.52 (0.61)***	2.26 (0.58)	2.27 (0.63)*
	Con	119	43.06 (7.98)	1.56 (0.52)	1.68 (0.54)	1.84 (0.47)	1.91 (0.48)	2.30 (0.45)	2.47 (0.53)
ALL	Men	143	42.65 (8.58)	1.74 (0.54)*	2.04 (0.74)	2.16 (0.62)	2.20 (0.65)	2.22 (0.51)*	2.38 (0.60)
	Women	83	42.30 (8.22)	1.89 (0.64)	2.10 (0.68)	2.16 (0.58)	2.19 (0.59)	2.39 (0.52)	2.37 (0.57)
PAT	Men	72	42.35 (8.99)	2.06 (0.47)	2.49 (0.64)	2.51 (0.56)	2.53 (0.61)	2.24 (0.58)	2.26 (0.64)
	Women	35	41.06 (8.81)	2.06 (0.65)	2.47 (0.68)	2.51 (0.50)	2.48 (0.63)	2.29 (0.59)	2.30 (0.62)
CON	Men	71	42.96 (8.19)	1.43 (0.41)	1.59 (0.53)	1.80 (0.45)	1.87 (0.50)	2.20 (0.41)	2.50 (0.53)
	Women	48	43.20 (7.74)	1.76 (0.61)	1.82 (0.52)	1.90 (0.48)	1.98 (0.45)	2.46 (0.45)	2.42 (0.54)
		N	D	SD	E	TI	M	VTA	PhTA
ALL	Pat	107	2.41 (0.58)***	2.75 (0.49)	2.23 (0.57)***	2.22 (0.57)	2.14 (0.59)***	1.95 (0.61)*	1.73 (0.53)**
	Con	119	1.92 (0.47)	2.82 (0.33)	1.60 (0.43)	2.21 (0.47)	1.68 (0.47)	2.12 (0.46)	1.91 (0.55)
ALL	Men	143	2.23 (0.58)*	2.78 (0.42)	1.90 (0.60)	2.21 (0.51)	1.94 (0.61)	2.04 (0.55)	1.89 (0.54)*
	Women	83	2.01 (0.55)	2.79 (0.40)	1.90 (0.58)	2.23 (0.54)	1.83 (0.52)	2.05 (0.52)	1.72 (0.53)
PAT	Men	72	2.45 (0.60)	2.76 (0.51)	2.22 (0.56)	2.24 (0.58)	2.19 (0.63)	1.97 (0.63)	1.79 (0.54)
	Women	35	2.32 (0.53)	2.72 (0.45)	2.23 (0.60)	2.19 (0.57)	2.05 (0.52)	1.93 (0.56)	1.60 (0.50)
CON	Men	71	2.01 (0.46)	2.80 (0.32)	1.57 (0.43)	2.18 (0.43)	1.68 (0.48)	2.11 (0.45)	1.99 (0.54)
	Women	48	1.79 (0.46)	2.83 (0.35)	1.66 (0.43)	2.26 (0.52)	1.68 (0.46)	2.14 (0.47)	1.80 (0.55)
		N	Neuroticism	Aggressiveness	Extraversion
ALL	Pat	107	2.32 (0.43)***	2.16 (0.38)**	2.31 (0.36)
	Con	119	1.71 (0.39)	2.27 (0.28)	2.23 (0.30)
ALL	Men	143	2.00 (0.53)	2.23 (0.34)	2.28 (0.33)
	Women	83	2.01 (0.47)	2.19 (0.33)	2.25 (0.34)
PAT	Men	72	2.33 (0.43)	2.19 (0.40)	2.32 (0.36)
	Women	35	2.30 (0.43))	2.11 (0.36)	2.29 (0.38)
CON	Men	71	1.65 (0.39)	2.27 (0.27)	2.23 (0.30)
	Women	48	1.80 (0.38)	2.26 (0.31)	2.20 (0.30)

*p < 0.05.

**p < 0.01.

***p < 0.001; N: number; STA: Somatic trait anxiety; PsTA: Psychic trait anxiety; SS: Stress susceptibility; LA: Lack of assertiveness; I: Impulsiveness; AS: Adventure seeking; D: Detachment; SD: Social desirability; E: Embitterment; TI: Trait irritability; M: Misstrust; VTA: Verbal trait aggression; PhTA: Physical trait aggression.

Table 4. Swedish universities Scales of Personality (SSP) factor structure in patients with psychotic illness, non-psychotic controls and in the Swedish normative sample (11).

	Patients			Controls			Normative sample
	Loading on			Loading on			Loading on
	Factor 1	Factor 2	Factor 3	Factor 1	Factor 2	Factor 3	Factor 1	Factor 2	Factor 3
STA	0.66	0.28	0.08	0.70	0.17	0.28	0.73	0.19	0.25
PsTA	0.85	0.07	−0.05	0.91	−0.02	0.06	0.89	0.02	−0.08
SS	0.69	0.10	−0.33	0.86	0.02	−0.04	0.80	0.16	−0.16
LA	0.83	−0.13	0.00	0.77	−0.35	−0.11	0.72	−0.27	−0.24
I	0.30	0.55	0.30	0.40	0.13	0.74	0.14	0.23	0.73
AS	−0.00	0.59	0.47	−0.11	0.28	0.76	−0.09	0.10	0.82
D	0.40	−0.08	−0.74	0.60	0.22	−0.46	0.35	0.40	−0.52
SD	0.15	−0.06	0.77	−0.07	−0.65	0.31	−0.10	−0.69	0.21
E	0.67	0.34	0.12	0.81	0.16	0.21	0.64	0.41	0.29
TI	0.31	0.74	−0.20	0.38	0.69	0.29	0.43	0.64	0.16
M	0.52	0.55	−0.10	0.75	0.31	−0.03	0.53	0.44	−0.04
VTA	−0.06	0.84	0.03	0.04	0.79	0.26	0.03	0.80	0.25
PhTA	0.07	0.81	−0.01	−0.03	0.67	0.19	−0.03	0.70	0.22

STA: Somatic trait anxiety; PsTA: Psychic trait anxiety; SS: Stress susceptibility; LA: Lack of assertiveness; I: Impulsiveness; AS: Adventure seeking; D: Detachment; SD: Social desirability; E: Embitterment; TI: Trait irritability; M: Misstrust; VTA: Verbal trait aggression; PhTA: Physical trait aggression; Bold values indicates loading factor > 0.45.

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