The effect of gender and subtype on platelet MAO in alcoholism

Decreased platelet MAO activity has been identified in male alcoholics with suggestions that this is primarily true of Type 2 alcoholics as defined by criteria from the Stockholm Adoption Study. Little information has been available regarding platelet MAO activity in female alcoholics. This study evaluated a group of 71 alcoholics receiving inpatient treatment, including 16 female alcoholics, for platelet MAO activity compared to controls. Female alcoholic's platelet MAO was significantly lower than controls and not different from activity levels in male alcoholics. Among male alcoholics, both Type 1 and Type 2 subgroups were lower than controls and Type 2 levels did not differ from Type 1 levels. Thus, we were unable to replicate a gender and subgroup low platelet MAO specificity among alcoholics, but did find significant differences between alcoholics and controls.     

Platelet monoamine oxidase and erythrocyte Catechol-o-Methyltransferase activity in alcoholism and controlled abstinence

This study substantiates previous reports that low platelet monoamine oxidase (MAO) activity is associated with alcoholism. Catechol-o-methyltransferase (COMT) activity in erythrocytes of alcoholics did not differ from that of controls. In 20 male alcoholics low platelet MAO activity was found during the first 3 days after hospitalization. The MAO activity increased in the next 2 weeks of abstinence and then tended to decrease again.     

Platelet monoamine oxidase activity and personality traits in alcoholics and methamphetamine dependents

Personality traits of alcoholics and methamphetamine dependents were examined by Karolinska scales of personality (KSP). The two groups differed with respect to Aggression, but, they were basically same in Impulsiveness. The biological marker platelet monoamine oxidase (MAO) activity showed a significant difference between the two groups. The low platelet MAO activity in alcoholics may suggest a certain biological basis to be involved in the etiology of dependence whereas the higher platelet MAO activity observed in methamphetamine dependents may reflect the prolonged use of methamphetamine and/or treatment with neuroleptics, or some biological basis.     

Platelet monoamine oxidase and plasma dopamine-beta-hydroxylase activities in non-abstinent chronic alcoholics. Relation to clinical parameters

Platelet monoamine oxidase (MAO) and plasma dopamine-beta-hydroxylase (DBH) activities were determined in 27 male non-abstinent chronic alcoholics. Compared to 24 normals, no significant difference in both enzyme activities was found. Alcoholics with at least one alcoholic first degree relative had a trend toward lower platelet MAO activity compared to those without such a history. Matched pair analysis showed that alcoholics of the former subgroup had significantly lower MAO activity than controls. Demented alcoholics had significantly reduced plasma DBH activity compared with the non-demented subgroup and with age, and sex, matched controls.     

Personality traits and platelet monoamine oxidase activity in alcoholic women

Twenty-nine women, sent to an inpatient treatment facility for rehabilitation and social training after treatment for heavy alcohol abuse, were compared with 29 female students of pharmacy or medicine with regard to platelet monoamine oxidase (MAO) activity and extraversion-impulsivity and anxiety-proneness personality traits. The alcoholic females were found to have slightly lower platelet MAO activity than the controls, the difference being considerably smaller than that previously found between male alcoholics and male controls. The personality pattern of the female alcoholics is in line with that previously found in alcoholic males. Thus, the female alcoholics were characterized by high anxiety proneness, impulsive acting-out behaviour, sensation seeking, social withdrawal, and a hostile attitude.     

Low platelet MAO activity associated with high dysfunctional impulsivity and antisocial behavior: evidence from drunk drivers

Rationale Low platelet monoamine oxidase (MAO) activity is associated with problem drinking and other deviant behaviors. Since the majority of alcohol abusers are smokers, and tobacco smoke has a direct inhibitory effect on the enzyme, these associations may not be meaningful.Objective The authors compared platelet MAO activity and impulsivity in police-referred subjects caught driving while intoxicated and in control subjects, controlling for smoking.Methods Platelet MAO activity was measured radioenzymatically and impulsivity scores obtained from questionnaires. Smoking status was self-reported.Results Subjects caught driving while intoxicated had significantly higher dysfunctional impulsivity and lower platelet MAO activity than control subjects. This difference in platelet MAO activity between the two groups was significant in non-smokers and ex-smokers.Conclusions These findings demonstrate that platelet MAO activity is lower in subjects with socially deviant behavior, and the association of low platelet MAO and problem drinking is not an artifact of smoking.     

Monoamine oxidase activity in different density gradient fractions of human platelets

Monoamine oxidase (MAO) activity measured in human platelets is reportedly altered by such drugs as epinephrine, lithium carbonate, and imipramine, and also reduced in a number of clinical disorders. To evaluate whether MAO activity might differ in platelet supopulations, density gradient centrifugation with arabino-galactan was used to prepare four platelet fractions that differed in weight and volume. MAO activity in the lightest and smallest platelet subpopulation was approximately one-half that in the heaviest and largest subpopulation. Because platelet weight and size are thought to be related to platelet age, it is possible that some drug effects on platelet MAO activity might represent changes in platelet turnover. Factors other than platelet turnover rates may contribute to individual differences in platelet MAO activity, however, since one group of individuals with markedly reduced platelet MAO activity exhibited no shift in the proportion of lighter versus heavier platelets nor in the relative amount of MAO activity in each density gradient subfraction.     

Association between substance use, personality traits, and platelet MAO activity in preadolescents and adolescents

This study examined the relationship between alcohol/illicit drug use, the Five-Factor Model (FFM) personality traits, aggressiveness (Agg), and hyperactivity (Hyp), and platelet monoamine oxidase (MAO) activity in a population-derived representative sample of preadolescents and adolescents (n=1172). Alcohol and illicit drug use was self-reported. The FFM personality inventories were filled in by mothers of the participants, and Agg and Hyp were rated by their class teachers. Higher scores in extraversion (E), Agg, and Hyp and lower scores in conscientiousness (C) together with older age were significant predictors of more frequent alcohol use in adolescents. No significant association was found between alcohol illicit drug use, and platelet MAO activity.     

Exploring patterns of alcohol misuse in treatment-seeking UK veterans: A cross-sectional study

AimsTo explore patterns of alcohol misuse in a sample of treatment-seeking veterans compared to the UK Armed Forces personnel population and the general public. Furthermore, the present study investigated which variables were associated with alcohol misuse in this sample, and in particular what factors were associated with increased or decreased severity of alcohol misuse.MethodThe present study investigated alcohol misuse in treatment-seeking veterans and compared it with the UK Armed Forces and the general public. In addition, it explored associations between sociodemographic, physical health and mental health variables and alcohol misuse.ResultsResults suggested that treatment-seeking veterans report different patterns of alcohol misuse compared to the UK Armed Forces and the general public. This group was more likely to report alcohol dependence and alcohol-related harm. They also reported higher levels of overall alcohol misuse than the general public. Mental health problems including PTSD, anxiety and depression, as well as anger, functional impairment and being single were all related to greater alcohol misuse. Being older and not in work were related to reduced alcohol misuse.ConclusionsThese findings add further weight to the importance of ensuring appropriate support is provided to personnel leaving the Armed Forces. Treatment-seeking veterans have specific patterns of alcohol-related needs that should be addressed. Knowing more about the common alcohol-related problems in this group can help inform and improve mental health interventions. Findings on related variables will help in identifying those individuals who may be at most risk of alcohol-related problems.     

Alcoholics who drink mouthwash: the spectrum of nonbeverage alcohol use

Nonbeverage alcohol (NBA), or substitutes for traditional forms of beverage alcohol, includes such substances as mouthwash, aftershave lotion and alcohol-based fuels. Literature pertaining to the prevalence, clinical significance and toxicity of this practice is reviewed, using illustrative cases from a series of 48 NBA consumers. It was found that 10-15% of alcoholics hospitalized in detoxication units have consumed NBA; half of these patients are regular consumers. Addiction to NBA itself may occur. Its use is primarily related to easy accessibility, rather than social or monetary factors. Polydrug misuse and antisocial personality disorder are more frequent in NBA users, but use is not pathognomic of end-stage alcoholism. The 48 NBA users reported surprisingly few toxic symptoms from acute ingestion, perhaps because tolerance to some substances in NBA may occur. Isopropyl alcohol was the exception, reproducibly causing symptoms suggestive of severe gastritis.     

Aggressiveness,family history of alcoholism,and the heart rate response to alcohol intoxication

Some sons of male alcoholics (SOMAs) are characterized by an increased heart rate (HR) response to alcohol intoxication, which is thought to reflect increased sensitivity to alcohol-induced reward. Such a response has also been related to increased physical aggression. However, the confounding effect of aggression in SOMAs may be obscuring the interpretation of these findings. The HR response to alcohol was therefore assessed in 4 groups: high/low aggressive SOMAs and high/low aggressive non-SOMAs. Results indicate that aggressive SOMAs had the highest intoxicated HR response and that they reported the most alcohol consumption. This suggests that in some cases the high comorbidity between alcohol misuse and aggression is related to an increased sensitivity to alcohol-induced reward.     

Field dependence in alcoholics: relation to years of drinking, severity of alcohol dependence and emotional distress

A number of factors were evaluated as predictors of field dependence (Embedded-Figures Test score) in alcoholics. In our sample, duration of excessive drinking and symptomatology of alcohol dependence were significantly related to the level of field dependence. These results fail to corroborate earlier findings and suggest that heightened field dependence in alcoholics is, at least partly, a consequence of alcohol misuse. In addition, a strong relationship was detected between the alcoholics' degree of anxiety and their degree of alcohol dependence. Possible bases for such a relationship are discussed.     

Identifying changes in the synaptic proteome of cirrhotic alcoholic superior frontal gyrus

Hepatic complications are a common side-effect of alcoholism. Without the detoxification capabilities of the liver, alcohol misuse induces changes in gene and protein expression throughout the body. A global proteomics approach was used to identify these protein changes in the brain. We utilised human autopsy tissue from the superior frontal gyrus (SFG) of six cirrhotic alcoholics, six alcoholics without comorbid disease, and six non-alcoholic non-cirrhotic controls. Synaptic proteins were isolated and used in two-dimensional differential in-gel electrophoresis coupled with mass spectrometry. Many expression differences were confined to one or other alcoholic sub-group. Cirrhotic alcoholics showed 99 differences in protein expression levels from controls, of which half also differed from non-comorbid alcoholics. This may reflect differences in disease severity between the sub-groups of alcoholics, or differences in patterns of harmful drinking. Alternatively, the protein profiles may result from differences between cirrhotic and non-comorbid alcoholics in subjects' responses to alcohol misuse. Ten proteins were identified in at least two spots on the 2D gel; they were involved in basal energy metabolism, synaptic vesicle recycling, and chaperoning. These post-translationally modified isoforms were differentially regulated in cirrhotic alcoholics, indicating a level of epigenetic control not previously observed in this disorder.     

Relationship between treatment outcome and subtype of alcoholism in men

The subdivision of alcoholism into type I and type II, as suggested by Cloninger et al., was applied to two groups of men alcoholics: 30 in treatment for alcoholism ("active" alcoholics) and 39 ex-alcoholics. Despite the fact that the duration of alcohol misuse did not differ between the groups, there were significantly more type II alcoholics among the ex-alcoholics and more type I alcoholics among the active alcoholics. The results seem to indicate a better prognosis in type II alcoholism. The type I and type II alcoholics differed also, as in previous studies, in their frequencies of drug misuse and criminality.     

Salicylate and mitochondrial monoamine oxidase function in Reye's syndrome

The main objective of this investigation was to study the effect of salicylate on platelet mitochondrial monoamine oxidase (MAO) activity isolated from blood of two patients with Reye's syndrome. Comparative studies were made with hospitalized children without Reye's syndrome (n = 27) and healthy children (n = 19) serving as controls. Platelet MAO was measured by a radioenzymatic technique with [14C]tyramine as a substrate. The results of this study showed that salicylate (1.0 mM) caused an appreciable inhibition of the platelet MAO activity of patients with Reye's syndrome at the onset of the illness. This was demonstrated by a greater than 50% reduction in enzyme maximum velocity (Vmax) value. The salicylate MAO-inhibitory effect was maintained throughout the duration of the illness. Salicylate had only a minimal MAO-inhibitory effect on platelets isolated from blood of recovered Reye's syndrome patients, healthy controls, and non-Reye's hospitalized children, and no apparent effect on enzyme Vmax values. These preliminary findings suggest that salicylate-induced mitochondrial injury may affect MAO function in children with Reye's syndrome.     

Alcohol misuse and psychological resilience among U.S. Iraq and Afghanistan era veterans

Objective

The present study sought to investigate the longitudinal effects of psychological resilience against alcohol misuse adjusting for socio-demographic factors, trauma-related variables, and self-reported history of alcohol abuse.

Methodology

Data were from the National Post-Deployment Adjustment Study (NPDAS) participants who completed both a baseline and one-year follow-up survey (N = 1090). Survey questionnaires measured combat exposure, probable posttraumatic stress disorder (PTSD), psychological resilience, and alcohol misuse, all of which were measured at two discrete time periods (baseline and one-year follow-up). Baseline resilience and change in resilience (increased or decreased) were utilized as independent variables in separate models evaluating alcohol misuse at the one-year follow-up.

Results

Multiple linear regression analyses controlled for age, gender, level of educational attainment, combat exposure, PTSD symptom severity, and self-reported alcohol abuse. Accounting for these covariates, findings revealed that lower baseline resilience, younger age, male gender, and self-reported alcohol abuse were related to alcohol misuse at the one-year follow-up. A separate regression analysis, adjusting for the same covariates, revealed a relationship between change in resilience (from baseline to the one-year follow-up) and alcohol misuse at the one-year follow-up. The regression model evaluating these variables in a subset of the sample in which all the participants had been deployed to Iraq and/or Afghanistan was consistent with findings involving the overall era sample. Finally, logistic regression analyses of the one-year follow-up data yielded similar results to the baseline and resilience change models.

Conclusions

These findings suggest that increased psychological resilience is inversely related to alcohol misuse and is protective against alcohol misuse over time. Additionally, it supports the conceptualization of resilience as a process which evolves over time. Moreover, our results underscore the importance of assessing resilience as part of alcohol use screening for preventing alcohol misuse in Iraq and Afghanistan era military veterans.     

Decreased platelet monoamine oxidase activity in female bulimia nervosa.

The involvement of brain serotonin systems in the pathophysiology of eating disorders has been repeatedly demonstrated in recent studies. Platelet MAO activity is an index of brain serotonin activity and lowered platelet MAO levels have been found in association with impulsive behaviors. In addition, some preliminary reports indicate that platelet MAO could be lowered in eating disorder patients. Methods: 47 patients with DSM-IV eating disorders were studied, including 30 with bulimia nervosa and 17 with anorexia nervosa binge eating-purging type. Platelet MAO activity was measured by isotopic methods using C-14 benzylamine and compared with a control group of 30 healthy subjects. Impulsive personality features were studied with specific rating scales. Results: Platelet MAO activity was significantly lower (4.4+/-2.4 nmol/h/10(8) platelets) in the bulimic patients than in the control group (6.9+/-2.5) (p<0.001). No significant differences were found between pure bulimics and binge eating-purging anorectics. Platelet MAO was inversely and significantly correlated with scores on impulsivity scales and with borderline personality disorder characteristics. Conclusions: Platelet MAO activity is lowered in patients with bulimia, which may reflect dysfunction in impulse control mechanisms. Since platelet MAO has a predominant genetic component, there is need for studies on the association of low platelet MAO and higher risk for developing eating disorders.     

Persistent cognitive deficits in community-treated alcoholic men and women volunteering for research: limited contribution from psychiatric comorbidity

OBJECTIVE: The contribution of psychiatric comorbidity to cognitive status was assessed in a sample of treatment-seeking alcoholics who met criteria to participate in studies of effects of chronic alcohol misuse on brain structure and cognition. METHOD: Alcoholic men (n = 43) and women (n = 21) who responded to notices about a research study were screened, clinically assessed and administered Wechsler Memory and Intelligence tests after 3 months of sobriety, on average. Cognitive performance was compared with that of an age-matched sample of healthy controls (n = 51). RESULTS: As a group, the alcoholics achieved significantly lower scores than controls on summary indices of the Wechsler Memory and Adult Intelligence Scales and showed greater decline from estimated premorbid intelligence levels than controls. Almost 60% of the alcoholics had at least one additional psychiatric (mood or anxiety) or past substance-dependence comorbidity. There were no marked sex differences in patterns of comorbidity. Comorbid alcoholics were younger, had consumed less alcohol over their lifetime and performed between noncomorbid alcoholics and controls on all tests. CONCLUSIONS: Mood and anxiety comorbidity did not necessarily compound poor cognitive test performance associated with chronic alcohol misuse. While unexpected, this finding suggests that, in this sample, poorer cognitive performance was more a function of alcoholism per se than nonalcoholic comorbidity.     

Both low and high activities of platelet monoamine oxidase increase the probability of becoming a smoker.

Platelet monoamine oxidase (MAO) activity is a marker of personality and psychiatric vulnerability, but the direct inhibitory action of tobacco constituents on the enzyme distorts the association. In the present investigation, data from a prospective longitudinal study of smoking behaviour and platelet MAO activity in adolescents at ages 15 and 18 years were sequentially analysed using a second-order multiple logistic regression analysis. The odds of regular smoking at 18 years increased significantly with increasing absolute deviation of platelet MAO activity at 15 years from the mean. That is, both low and high platelet MAO activity at 15 years predicted a higher probability of becoming a smoker. These data suggest that smoking is associated with low platelet MAO activity not only because of the direct inhibitory effect of tobacco constituents on the enzyme, but also because subjects with low platelet MAO activity are more likely to become smokers. Furthermore, the possible association between above-average platelet MAO activity and behavioural phenotypes should be reexamined.     

Adaptive and maladaptive impulsivity, platelet monoamine oxidase (MAO) activity and risk-admitting in different types of risky drivers

Rationale Platelet monoamine oxidase (MAO) activity reflects serotonergic functioning associated with impulsive behaviour, but the significance of these associations to real-life impulsive behaviour in healthy subjects is not clear.Objectives The present study explores impulsivity and platelet MAO activity among people with driving violations.Materials and methods We compared facets of impulsivity and platelet MAO activity in 1,004 male drivers, out of whom 203 had been caught by the police driving drunk and 292 had been caught exceeding speed limits and committing other non-alcohol-related driving violations. Subjects with speeding and other non-alcohol-related violations were further divided according to their self-reported risk-admitting of exceeding speed limits.Results While drunk driving was associated only with maladaptive types of impulsivity, exceeding speed limits was associated with functional impulsivity and excitement seeking and, to a lesser degree, with dysfunctional impulsivity. Drunk drivers had lower platelet MAO activity. Risk-admitting high-risk drivers had higher platelet MAO activity, neuroticism-related impulsivity, dysfunctional impulsivity and excitement seeking compared to all other groups and higher functional impulsivity compared to controls. Risk-denying high-risk drivers had only higher functional impulsivity compared to controls.Conclusions This study demonstrates different expressions of functional and dysfunctional impulsivity in behaviour. While platelet MAO activity is lower in alcohol-related risky behaviour, non-alcohol-related self-acknowledged risky behaviour is related to higher platelet MAO activity. Thus, deviance towards lower as well as higher end of central serotonergic functioning may lead to impulsive behaviour. While self-reported impulsivity did not correlate with MAO activity, both MAO activity and impulsivity were related to risky behaviour.