Comparison of participants and nonparticipants in a neuroendocrine investigation of psychosis

Patients participating to neurobiological research in early psychosis: A selected subgroup?

AIM

Selection bias could be an important limiting factor in psychiatric neurobiological research. The study aim was to compare, within an early psychosis program, patients who agreed to participate to neurobiological research with patients who refused.

METHODS

284 patients with early psychosis were assessed at baseline on a large set of socio-demographic and clinical variables and were followed-up over 36 months.

RESULTS

There were no differences between groups, except regarding forensic/psychiatric history, lifetime substance abuse and social-occupational level during follow-up.

CONCLUSIONS

While patients participating to neurobiological research seem representative of our clinical cohort, the few differences identified may deserve attention.

Pubertal neuromaturation, stress sensitivity, and psychopathology

Normal adolescent development is often accompanied by transient emotional and behavioral problems. For most individuals with postpubertal-onset adjustment problems, there is a resolution by early adulthood and relative stability through the adult life span. But for a minority, adjustment problems escalate during adolescence and portend the development of serious mental illness in adulthood. In this article, we explore adolescent behavioral changes and neurodevelopmental processes that might contribute to stress sensitivity and vulnerability for the emergence of the mental disorders. Of particular interest is the role that hormonal changes might play in the expression of genetic vulnerabilities for psychopathology. Drawing on recent findings from clinical research and behavioral neuroscience, we describe the ways in which postpubertal hormones might alter brain function and, thereby, behavior. It is concluded that there are both activational and organization effects of hormones on the adolescent brain, and these contribute to developmental discontinuities in behavioral adjustment. Implications for adult psychopathology and preventive intervention are discussed.

Minor physical anomalies, dermatoglyphic asymmetries, and cortisol levels in adolescents with schizotypal personality disorder

OBJECTIVE

A relationship between schizotypal personality disorder and schizophrenia has been documented in behavioral genetic studies, and there are similarities in the cognitive deficits and brain abnormalities associated with these disorders. Adolescents with schizotypal personality disorder are of particular interest because the postpubertal period is a critical one for the development of a DSM axis I disorder. It is likely that some schizotypal adolescents will remain stable over time, some will improve, and a subgroup will develop schizophrenia. This study tested the hypotheses that, like schizophrenic patients, schizotypal adolescents manifest an elevated rate of minor physical and dermatoglyphic anomalies, both of which suggest prenatal neurodevelopmental abnormalities. Cortisol release is also of interest because of evidence that the hypothalamic-pituitary-adrenal axis may influence the behavioral expression of vulnerability to schizophrenia.

METHOD

Minor physical anomalies, dermatoglyphic asymmetries, and salivary cortisol levels were measured in three groups of adolescents: 20 with schizotypal personality disorder, 20 with other personality disorders, and 26 with no disorder. Assessments began at noon, and four saliva samples were obtained at hourly intervals.

RESULTS

The schizotypal personality disorder group showed more minor physical anomalies and dermatoglyphic asymmetries than the normal comparison group and higher cortisol levels than both of the other groups. Group differences in cortisol level were most pronounced at the beginning of the evaluation. Cortisol level and age were positively correlated.

CONCLUSIONS

The findings support the assumption that schizotypal personality disorder is associated with perturbations in fetal neurodevelopment and, under some circumstances, a heightened cortisol response.

Correlates of aggressive behaviour in schizophrenia: an overview

OBJECTIVE

This review aims to critically evaluate the reported biological, psychological and social correlates of aggression in schizophrenia and to delineate those correlates which could be of use clinically and those which require further research.

METHOD

The literature from 1974-1996 was searched using Psychlit and supplemented by suggestions from senior members of the authors' Department.

RESULTS

Past history of aggression, psychopathology, extrapyramidal side effects of neuroleptic medications, substance abuse, reduced serotonin function, antisocial and impulsive personality traits, neurological/neuropsychological deficits, electroencephalography, neuroimaging abnormalities and environmental factors were all found to be correlated with aggressive behaviour in schizophrenia. However, there are many methodological limitations of previous studies in this field, often leading to inconsistent and inconclusive findings.

CONCLUSIONS

Some tentative conclusions regarding clinically useful predictors of aggression in schizophrenia can be drawn at this stage. There is a need for methodological limitations of previous studies to be overcome before more firm conclusions can be reached.

Studies of aggressive behaviour in schizophrenia: is there a response bias?

Of 73 patients who met selection criteria to enter into a study on aggressive behaviour in schizophrenia, 11 patients (15.1%) did not participate. The participants and non-participants were similar in age, gender ratio and proportion who had aggressive behaviour. The participants, however, had a longer duration of illness, a longer duration of current admission, were more likely to suffer from residual schizophrenia, but less likely to suffer from disorganized schizophrenia and were less severely ill than the non-participants. These results indicate the need, in studies of aggressive behaviour in schizophrenia, to consider non-response bias as a confounding variable.