Biological markers, with special regard to platelet monoamine oxidase (trbc-MAO), for personality and personality disorders

Monoamine oxidase and agitation in psychiatric patients

Subjects with schizophrenia or conduct disorder display a lifelong pattern of antisocial, aggressive and violent behavior and agitation. Monoamine oxidase (MAO) is an enzyme involved in the degradation of various monoamine neurotransmitters and neuromodulators and therefore has a role in various psychiatric and neurodegenerative disorders and pathological behaviors. Platelet MAO-B activity has been associated with psychopathy- and aggression-related personality traits, while variants of the MAOA and MAOB genes have been associated with diverse clinical phenotypes, including aggressiveness, antisocial problems and violent delinquency. The aim of the study was to evaluate the association of platelet MAO-B activity, MAOB rs1799836 polymorphism and MAOA uVNTR polymorphism with severe agitation in 363 subjects with schizophrenia and conduct disorder. The results demonstrated significant association of severe agitation and smoking, but not diagnosis or age, with platelet MAO-B activity. Higher platelet MAO-B activity was found in subjects with severe agitation compared to non-agitated subjects. Platelet MAO-B activity was not associated with MAOB rs1799836 polymorphism. These results suggested the association between increased platelet MAO-B activity and severe agitation. No significant association was found between severe agitation and MAOA uVNTR or MAOB rs1799836 polymorphism, revealing that these individual polymorphisms in MAO genes are not related to severe agitation in subjects with schizophrenia and conduct disorder. As our study included 363 homogenous Caucasian male subjects, our data showing this negative genetic association will be a useful addition to future meta-analyses.

Should the scope of addictive behaviors be broadened to include pathological gambling?

AIMS

Pathological gambling is currently considered an impulse control disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM). This paper considers the prospect of reclassifying and broadening the substance use disorders to include non-pharmacological addictions such as pathological gambling.

METHODS

Literature reviews were conducted on areas relevant to pathological gambling and its classification and similarities to substance use disorders.

RESULTS

The diagnostic criteria for pathological gambling are outlined across the three versions of the DSM since its initial introduction. The paper also describes instruments that have been used to assess the disorder, basic epidemiology and some biological and genetic data, especially in terms of potential overlap with substance use disorders. Similarities and differences with respect to treatments are reviewed as well.

CONCLUSIONS

Both advantages and disadvantages should be considered with respect to expanding the classification system to include pathological gambling within the context of addictive disorders.

Personality Characteristics as Risk Indications of Alcohol Use and Violent Behavior in Male and Female Adolescents

Abstract. The present study focused on personality characteristics in adolescent boys (n = 414) and girls (n = 552) in 8th grade with self-reported violent behavior and risky alcohol use. Adolescents with indications of violent behavior and/or risky alcohol use, compared to others, were generally more impulsive, had a stronger need for change and action, were less adjusted and socially conforming, as well as more aggressive. The findings pointed toward a clustering of problem behaviors. Furthermore, adolescents with a combination of violent behavior and alcohol use had more pronounced personality scores than subjects who reported only one of these behaviors. The main finding was that among girls these behaviors appeared to be associated with more deviant levels of the personality characteristics in focus.

Platelet monoamine oxidase in healthy 9- and 15-years old children: the effect of gender, smoking and puberty

1. The effect of gender, smoking and pubertal development on platelet monoamine oxidase (MAO) activity was described in a randomly selected, large sample of 9- and 15-years old healthy children. 2. Platelet MAO activity was measured in 1129 children by a radioenzymatic method with beta-phenylethylamine as the substrate. Smoking habits were reported in an anonymous questionnaire. Pubertal status was assessed visually using Tanner's stages. 3. Boys, younger children and smokers had significantly lower platelet MAO activity than girls, older children and non-smokers, respectively. Girls in Tanner's stage V for breast and pubic hair development had significantly lower MAO than girls in stage IV. 4. Differences in gender, age, pubertal status and smoking habits must be taken into account if the relationship between platelet MAO activity, personality and psychiatric disorders is studied in children.