Severity Indices of Personality Problems (SIPP-118) in adolescents: reliability and validity

The Severity Indices of Personality Problems (SIPP-118; Verheul et al., 2008) is a self-report questionnaire focusing on core components of (mal)adaptive personality functioning. The SIPP-118 was developed and validated in an adult population. In adult populations, the 16 facets of the SIPP-118 fit into 5 higher order domains: self-control, identity integration, relational capacities, social concordance, and responsibility. In this study we present the 1st psychometric properties of the SIPP-118 in adolescents. We compared the SIPP-118 scores of a patient and a nonpatient sample of adolescents, and compared personality disordered and non-personality disordered adolescents. In addition, the relationship between scores on the SIPP-118 and other clinical instruments (Symptom Checklist-90-Revised; SCL-90-R; Derogatis, 1975; Dimensional Assessment of Personality Pathology-Basic Personality; DAPP-BQ; Livesley & Jackson, 2002) was investigated. The questionnaires were completed by 378 adolescent patients and 389 adolescents in the community. Facets appeared to be homogeneous, as alpha coefficients ranged from .62 to .89, indicating moderate to acceptable reliability. Also, more pathological SIPP-118 scores were found in the patient sample, and more specifically in the personality disordered sample, suggesting that the facet scores of the SIPP-118 can discriminate between various populations (divergent validity). Correlation with other clinical instruments was moderate to high (-.82 to .10). Taken together, the SIPP-118 seems to be a promising instrument measuring personality pathology in adolescents.     

Individual differences in dopamine efflux in nucleus accumbens shell and core during instrumental learning

Combined activation of dopamine D1- and NMDA-glutamate receptors in the nucleus accumbens has been strongly implicated in instrumental learning, the process in which an individual learns that a specific action has a wanted outcome. To assess dopaminergic activity, we presented rats with two sessions (30 trials each) of a one-lever appetitive instrumental task and simultaneously measured dopamine efflux in the shell and core accumbens subareas using in vivo microdialysis. Dopamine efflux was increased during each session in all areas. The behavioral performance of the rats in the second session led us to divide them into a learning group (>90% correct trials) and a non-learning group. In the first session, the rats of the learning group showed significantly higher increases. The difference was most pronounced in the shell. In the second session, the dopamine increase was similar in both groups, although the learning groups now pressed the lever about three times more often and consequently obtained more rewards. We conclude that task-related activation of dopamine efflux is different between learning and non-learning rats only during the learning phase. These results support the pharmacological evidence that dopamine is of particular importance during the instrumental learning process.     

The burden of disease among adolescents with personality pathology: quality of life and costs

In adults, personality disorders are associated with a low quality of life and high societal costs. To explore whether these findings also apply to adolescents, 131 adolescent patients were recruited from a mental health care institute in The Netherlands. Axis I and Axis II disorders were diagnosed using semi-structured interviews. The EuroQol EQ-5D was used to measure quality of life and costs were measured by the Trimbos and Institute for Medical Technology Assessment Questionnaire on Costs Associated with Psychiatric Illness. The mean EQ-5D index value was 0.55. The mean direct medical cost in the year prior to treatment was €14,032 per patient. The co-occurrence of Axis I and Axis II disorders was a significant predictor of a low quality of life. Direct medical costs were higher for the depressive personality disorder. This study shows that the burden of disease among adolescents with personality pathology is high. This high burden provides evidence to suggest that further research and development of (cost-)effective treatment strategies for this population may be worthwhile.     

Noradrenergic action in prefrontal cortex in the late stage of memory consolidation

These experiments investigated the role of the noradrenergic system in the late stage of memory consolidation and in particular its action at beta receptors in the prelimbic region (PL) of the prefrontal cortex in the hours after training. Rats were trained in a rapidly acquired, appetitively motivated foraging task based on olfactory discrimination. They were injected with a beta adrenergic receptor antagonist into the PL 5 min or 2 h after training and tested 48 h later. Rats injected at 2 h showed amnesia, whereas those injected at 5 min had good retention, equivalent to saline-injected controls. Monitoring extracellular noradrenaline efflux in PL by in vivo microdialysis during the first hours after training revealed a significant increase shortly after training, with a rapid return to baseline, and then another increase around the 2-h posttraining time window. Pseudo-trained rats showed a smaller early efflux and did not show the second wave of efflux at 2 h. These results confirm earlier pharmacological and immunohistochemical studies suggesting a delayed role of noradrenaline in a late phase of long-term memory consolidation and the engagement of the PL during these consolidation processes.     

Prevalence and comorbidity of axis I and axis II disorders among treatment refractory adolescents admitted for specialized psychotherapy

Research shows that approximately half of the adolescents in a clinical setting suffer from a personality disorder (PD). This finding has not yet been replicated in Europe. To test whether this finding also applies to Europe, structured diagnostic interviews for both Axis I and Axis II disorders were used in 257 adolescents who were admitted to a highly specialized mental health setting in The Netherlands. In this study we found that 40.5% of the adolescents were diagnosed with at least one personality disorder. Most adolescents with a personality disorder (78.9%) also suffered from one or more Axis I disorders. These results are comparable to rates found in previous prevalence studies of personality disorders in both adolescents and adults. Our results provide further evidence to support the cross-national generalizability of the diagnosis of PD in adolescents.