Background: Personality is considered as an important aspect in persons with psychotic disorders. Several studies have investigated personality in schizophrenia. However, no study has investigated stability of personality traits exceeding three years in patients with schizophrenia. This study aims to investigate the stability of personality traits over a five-year period among patients with schizophrenia and non-psychotic individuals and to evaluate case-control differences. Methods: Patients with psychotic disorders (n = 36) and non-psychotic individuals (n = 76) completed Swedish universities Scales of Personality (SSP) at two occasions five years apart. SSP scores were analysed for effect of time and case-control differences by multiple analysis of covariance (MANCOVA) and within-subjects correlation. Results: MANCOVA within-subjects analysis did not show any effect of time. Thus, SSP mean scale scores did not significantly vary during the five-year interval. Within subject correlations (Spearman) ranged 0.30-0.68 and 0.54-0.75 for the different SSP scales in patients and controls, respectively. Patients scored higher than controls in SSP scales Somatic Trait Anxiety, Psychic Trait Anxiety, Stress Susceptibility, Lack of Assertiveness, Detachment, Embitterment, and Mistrust. Conclusion: The stability of the SSP personality trait was reasonably high among patients with psychotic disorder, although lower than among non-psychotic individuals, which is in accordance with previous research.

Background: Personality is considered as an important aspect that can affect symptoms and social function in persons with schizophrenia. The personality questionnaire Swedish universities Scales of Personality (SSP) has not previously been used in psychotic disorder. Aims: To investigate if SSP has a similar internal consistency and factor structure in a psychosis population as among healthy controls and if patients with psychotic disorders differ from non-psychotic individuals in their responses to the SSP. Methods: Patients with psychotic disorders (n = 107) and healthy controls (n = 119) completed SSP. SSP scores were analyzed for internal consistency and case-control differences by Cronbach’s alfa and multiple analysis of covariance, respectively. Results: Internal consistencies among patients were overall similar to that of controls. The patients scored significantly higher in seven (Somatic trait anxiety, Psychic trait anxiety, Stress susceptibility, Lack of assertiveness, Detachment, Embitterment, Mistrust) and lower in three (Physical trait aggression, Verbal trait aggression, Adventure seeking) of the 13 scales of the inventory. In three scales (Impulsiveness, Social desirability and Trait irritability) there was no significant difference between the scoring of patients and healthy controls. Conclusion: The reliability estimates suggest that SSP can be used by patients with psychotic disorders in stable remission. Patients score higher on neuroticism-related scales and lower on aggression-related scales than controls, which is in accordance with earlier studies where other personality inventories were used.

Objective To investigate associations between Swedish universities Scales of Personality (SSP) and scales of the following personality instruments: Structured Clinical Interview for DSM-III-R axis II screening questionnaire (SCID-II screen), revised NEO personality inventory (NEO-PI-R), revised Chapman scales (Chapman) and the psychotic traits questionnaire (STQ).Methods Healthy individuals (n=406) completed self-report personality questionnaires including SSP and at least one more personality inventory. Correlations were calculated between the 13 different SSP subscales as well as SSP’s three factors and factors and scales/subscales in SCID-II screen, NEO-PI-R, Chapman and STQ. The main factors of the various instruments were factor analysed. ICC were calculated.Results SSP Neuroticism factor correlated with SCID-II cluster C (r=0.71), NEO Neuroticism (r=0.80) and Chapman Social anhedonia (r=0.62). SSP Extraversion factor correlated with NEO Extraversion (r=0.63) and SSP Aggressiveness factor with NEO Agreeableness (r=-0.62). Strong correlations between SSP factors and scales and scales of the other instruments were sparse, although weaker correlations were common.Conclusion SSP is a useful investigation tool when measuring personality traits related to temperament-like features. SSP partly correlates well to especially three of the NEO-PI-R factors. The different personality inventories are not completely comparable to each other. Instead, they measure personality aspects in partly different ways.

BackgroundPersonality can be determined through a variety of tests, and different personality inventories are used to map individual differences of personality traits. We aimed to investigate correlations between Swedish universities Scales of Personality (SSP) and scales of the following personality constructs: Structural Clinical Interview for DSM-III-R axis II screening questionnaire (SCID-II screen), revised NEO personality inventory (NEO-PI-R), Karolinska Scales of Personality (KSP), revised Chapman scales (Chapman), Schizotype, Impulsive and Borderline scales (SKIB-79) and Health-Relevant 5-factor Personality inventory (HP5i). MethodsHealthy individuals were drawn from a population register or recruited among students or hospital staff members, who had previously participated in clinical studies at the Karolinska Institutet and were asked to participate. In addition, a group of non-psychotic siblings and parents of patients with psychotic disorder were asked to be part of the study. All participants were given complete description of the study and participated after having given informed written consent. Data from 615 participants (265 women and 350 men) were used. The participants completed self-report personality questionnaires including SSP and at least one more personality inventory. Correlations where calculated between the 13 different SSP subscales as well as SSP's three factors and factors and scales/subscales from the SCID-II screen, NEO-PI-R, KSP, Chapman, and SKIB-79 and HP5i.Based on the 91 items that are common to the SSP and KSP-196, the 13 different personality scales were calculated according to the SSP manual. The items presented in KSP and HP5i were drawn from KSP-196. Results SSP vs. SCID-II screenTwo SSP-scales, i.e. Psychic trait anxiety and Embitterment correlated with SCID-II screen personality disorders at a level of r>0.6: Psychic trait anxiety correlated with Phobic and Dependent personality disorders and Embitterment with Personality disorder not otherwise specified (NOS). The SSP Neuroticism factor was also strongly correlated with these three SCID-II screen personality disorders.