Platelet Monoamine Oxidase Activity in Acute Schizophrenia: Relationship to Symptomatology and Neuroleptic Medication

SummaryPlatelet MAO activity was assessed in 35 schizophrenics during a trial of the isomers of flupenthixol. Enzyme activity was unrelated to severity of symptoms, the presence of delusions, hallucinations or thought disorder or to negative symptoms. In a few patients MAO activity fluctuated widely with time, but in the group of patients on medication there was a slow decrease in enzyme activity which was significant after 28 days of treatment. Enzyme activity after 14 days' drug treatment was still correlated with activity before treatment, but after 28 days this significant correlation disappeared. Slow effects of neuroleptic drugs on platelet MAO activity may explain previous findings of reduced activity of the enzyme in schizophrenia.

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Platelet monoamine oxidase activity and life stress as predictors of psychopathology and coping in a community sample

Psychological Medicine ◽

10.1017/s0033291700011041 ◽

1989 ◽

Vol 19 (1) ◽

pp. 79-90 ◽

Cited By ~ 8

Author(s):

Joanne Boyd Irving ◽

Robert D. Coursey ◽

Monte S. Buchsbaum ◽

Dennis L. Murphy

Keyword(s):

Monoamine Oxidase ◽

Mental Health Professionals ◽

Life Stress ◽

Stressful Life Events ◽

Community Sample ◽

Adult Males ◽

Platelet Mao ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase

SynopsisThe present study, using a diathesis-stress model, attempted to confirm prior findings with platelet monoamine oxidase (MAO) activity and stress in a middle-aged, non-clinic population. One hundred and seventy-eight adult males from a statewide community club were tested for platelet MAO activity and stressful life events and were also given a variety of psychological measures of both psychopathology and psychosocial coping. The data were examined both for correlations across the total sample and for a comparison of high-risk groups (top and bottom 15% of MAO activity) with a middle MAO group. Low platelet MAO activity was related to a higher incidence of contact with mental health professionals, and more frequent use of alcohol and cigarette smoking. High MAO activity was related to higher levels of anxiety and somatization. High levels of stress were related to increased psychosocial problems reported for female and family members, higher scores on two schizophrenia-related MMPI scales (schizophrenia and paranoia subscales), but fewer idiosyncratic associations, elevated hypomanic, depression, and anxiety scores, increased alcohol use, and increased use of prescribed antianxiety and sedative medication. Neither MAO nor stress were related to current levels of psychosocial coping. Moreover, no interaction effects were uncovered for MAO activity and stress combined.

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Kinetics and Thermolability of Platelet Monoamine Oxidase in Cluster Headache and Migraine

Cephalalgia ◽

10.1046/j.1468-2982.1984.0402125.x ◽

1984 ◽

Vol 4 (2) ◽

pp. 125-134 ◽

Cited By ~ 19

Author(s):

Elisabet Waldenlind ◽

Jan Sääf ◽

Karl Ekbom ◽

Svante Ross ◽

Lars-Olof Wahlund ◽

...

Keyword(s):

Monoamine Oxidase ◽

Cluster Headache ◽

Control Group ◽

Enzyme Properties ◽

Headache Disorders ◽

Platelet Mao ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase ◽

C 30

Platelet monoamine oxidase activity (MAO) from 33 cluster headache patients (17 males, 16 females) and 34 migraine patients (16 males, 18 females) was assayed. The kinetic constants (apparent V max and apparent K m ) and the thermolability, measured as the ratio of the platelet MAO activity after and before heat treatment (+52°C, 30 min), were determined. The MAO activity and V max values were significantly lower in cluster headache than in migraine and in both headache disorders compared to a control group (62 males, 66 females). When comparing all groups, K m was not significantly different except for migraine females, who had lower K m values compared to control females. Thermolability was significantly higher in cluster headache than in migraine and in both headache disorders compared to the control group. Smokers of five cigarettes or more per day had significantly lower Vmax values but similar K m and thermolability values compared to those smoking less or nothing. The findings of low maximal velocities and high thermolability of platelet MAO in cluster headache and migraine are suggested to represent constitutionally different enzyme properties.

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Genetics of Platelet MAO Activity in Discordant Schizophrenic and Normal Twins

The British Journal of Psychiatry ◽

10.1192/bjp.142.6.560 ◽

1983 ◽

Vol 142 (6) ◽

pp. 560-565 ◽

Cited By ~ 50

Author(s):

Michael A. Reveley ◽

Adrianne M. Reveley ◽

Christine A. Clifford ◽

Robin M. Murray

Keyword(s):

Monoamine Oxidase ◽

Genetic Control ◽

Platelet Mao ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase ◽

The Mean ◽

Mz Twins ◽

Age And Sex

SummaryPlatelet monoamine oxidase (MAO) activity was compared in four age and sex-matched groups: monozygotic (MZ) twins discordant for schizophrenia, normal MZ twins, normal dizygotic (DZ) twins and unrelated individuals. Among the twin groups, schizophrenic and normal, there was a remarkably consistent degree of genetic control amounting to 70–80 per cent of the variation in activity. The mean platelet MAO activity of the schizophrenic twins was significantly lower than that of controls, but not than that of their psychiatrically well, neuroleptic-free cotwins; indeed the correlation for the MZ twins discordant for schizophrenia was almost exactly the same as that for the normal MZs. Thus, lower platelet MAO activity in schizophrenia, where it is found, is genetically modulated and not the result of the illness or its treatment.

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Altered platelet monoamine oxidase activity in affective disorders

Psychological Medicine ◽

10.1017/s0033291700034048 ◽

1979 ◽

Vol 9 (4) ◽

pp. 729-736 ◽

Cited By ~ 65

Author(s):

John Mann

Keyword(s):

Affective Disorders ◽

Lithium Carbonate ◽

Depressive Illness ◽

Reactive Depression ◽

Platelet Mao ◽

Genetic Mechanisms ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase ◽

Bipolar Patients

SYNOPSISPlatelet MAO activity was found to be elevated in primary depressive illness, and the severity to correlate positively with MAO activity. The reactive depression subgroup's mean platelet MAO activity was not significantly different from that of the controls. The endogenous group's unipolar and bipolar subgroups had significantly different platelet MAO activity, respectively high and low. The differences in MAO activity between unipolar and bipolar patients appeared to persist in the well state, but not after lithium carbonate therapy. These differences in MAO activity were apparent with the substrate tyramine but not with benzylamine. Altered MAO activity in patients with affective disorders may be determined through genetic mechanisms.

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Low Platelet Monoamine Oxidase Activity in Sensation-Seeking Bullfighters

CNS Spectrums ◽

10.1017/s1092852900006787 ◽

1999 ◽

Vol 4 (12) ◽

pp. 21-24 ◽

Cited By ~ 5

Author(s):

José Luis Carrasco ◽

Jerónimo Sáiz-Ruiz ◽

Marina Díaz-Marsá ◽

Jesús César ◽

Juan José López-Ibor

Keyword(s):

Monoamine Oxidase ◽

Sensation Seeking ◽

Behavioral Pattern ◽

Control Group ◽

Platelet Mao ◽

Isotopic Methods ◽

Healthy Control ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase

AbstractIn this study, we attempt to demonstrate an association between low platelet monoamine oxidase (MAO) activity, as assessed by isotopic methods, and the stable behavioral pattern of sensation- and risk-seeking of professional bull-fighters. Sixteen professional bullfighters were studied and compared with a control group of 46 healthy control subjects who did not engage in risky jobs or activities. The group of bullfighters had significantly reduced platelet MAO activity compared with the control group (P<0.05). Bullfighters were shown to be significantly more extroverted and sensation-seeking than controls on various temperament scales. A predisposition to engage in risky activities (eg, bullfighting) and sensation-seeking could be partly conditioned by the presence of biological components of personality manifested by a significantly decreased platelet MAO activity.

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Platelet Monoamine Oxidase Activity in Schizophrenia

The British Journal of Psychiatry ◽

10.1192/bjp.134.4.366 ◽

1979 ◽

Vol 134 (4) ◽

pp. 366-371 ◽

Cited By ~ 26

Author(s):

John Mann ◽

K. M. Thomas

Keyword(s):

Monoamine Oxidase ◽

Normal Subjects ◽

Control Groups ◽

Platelet Mao ◽

Duration Of Illness ◽

Before And After ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase ◽

Institutionalized Patients

SummaryA study was made of platelet monoamine oxidase (MAO) activity in non-medicated, newly-admitted schizophrenics and institutionalized chronic schizophrenics both on and off medication. These patients were compared to two control groups: normal subjects and brain-damaged institutionalized patients. No relationship was found between platelet MAO activity and the severity or duration of illness, duration of psychotropic medication, presence of auditory hallucinations or institutionalization. Mean platelet MAO activity did not differ significantly between the schizophrenic subgroups and control groups. Thirty-one patients studied before and after treatment with phenothiazines showed no significant change in platelet MAO activity. The findings did not indicate a relationship between schizophrenia, its treatment or outcome and platelet MAO activity.

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Platelet Monoamine Oxidase Activity and 5-Hydroxytryptamine Uptake in Agoraphobic Patients

The British Journal of Psychiatry ◽

10.1192/bjp.155.5.680 ◽

1989 ◽

Vol 155 (5) ◽

pp. 680-685 ◽

Cited By ~ 1

Author(s):

J. Flaskos ◽

N. Theophilopoulos ◽

A. J. George

Keyword(s):

Serotonin Uptake ◽

Mean Values ◽

Platelet Serotonin ◽

Platelet Mao ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase ◽

Uptake Velocity ◽

Depressive Patients ◽

Uptake And Metabolism

Platelet MAO activity and platelet serotonin uptake were determined in 20 agoraphobic and 16 neurotic depressive out-patients, and 19 healthy volunteers. Agoraphobic patients were characterised by significantly higher mean values of platelet MAO activity compared with the other two groups, while neurotic depressive patients exhibited significantly higher maximum platelet serotonin uptake velocity. These findings are compatible with an abnormality in the uptake and metabolism of serotonin.

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A Biomarker of Risk-Prone Behavioral Phenotype Correlates With Winning in a Game of Skill

Journal of Psychophysiology ◽

10.1027/0269-8803/a000165 ◽

2016 ◽

Vol 30 (4) ◽

pp. 155-164 ◽

Cited By ~ 2

Author(s):

Maive Otsa ◽

Marika Paaver ◽

Jaanus Harro ◽

Talis Bachmann

Keyword(s):

Social Relations ◽

Real Life ◽

Activity Level ◽

Maladaptive Behavior ◽

The Novel ◽

Platelet Mao ◽

Game Situation ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase

Abstract. The predisposition to take risk is a personality trait associated with dangerous or maladaptive behavior. Related to this, biomarkers associated with risk proneness such as low platelet monoamine oxidase (MAO) activity level are typically considered as prognostic for higher likelihood of undesirable behavior in real-life settings. In this study we explored whether this biomarker is also indicative of risk proneness in a game situation where serious real-life adaptations and motivations are absent or minimized and risk is more or less symbolic. We adapted a game of skill where in order to get a high score “risky” actions had to be taken by the players. Scores obtained in the game correlated with the (relatively low) platelet MAO activity. Our results show that (1) the same markers that are informative for real-life behavior and adaptations involving risk and/or sensorimotor skills based performance may be informative also in a game setting, (2) in specific circumstances biomarkers associated with predisposition to risk may be associated with success, and (3) the novel game of skill tested in this context has a potential to be developed to a model of risk-involving behavior allowing quantifiable dependent measures of performance and purposeful manipulation of variables without real adverse effects on health or social relations.

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The Effect of Lithium on Platelet Monoamine Oxidase Activity in Bipolar and Schizoaffective Disorders

The British Journal of Psychiatry ◽

10.1192/bjp.140.2.192 ◽

1982 ◽

Vol 140 (2) ◽

pp. 192-198 ◽

Cited By ~ 7

Author(s):

Herbert Y. Meltzer ◽

Patricia Tueting ◽

Herbert Jackmann

Keyword(s):

Monoamine Oxidase ◽

Rating Scale ◽

Lithium Treatment ◽

Lithium Carbonate ◽

Global Assessment Scale ◽

Platelet Mao ◽

Mao Activity ◽

Platelet Mao Activity ◽

Platelet Monoamine Oxidase ◽

Psychiatric Rating Scale

SummaryPlatelet monoamine oxidase (MAO) activity was studied in 33 in-patients with bipolar and schizoaffective disorder who were treated with lithium. Platelet MAO activity was found to increase following 10–41 days of lithium treatment compared to a prior drug free period, and the increase was positively correlated with the duration of lithium treatment. The increase in platelet MAO activity was not correlated with clinical improvement as measured by the Brief Psychiatric Rating Scale (BPRS) and the Global Assessment Scale (GAS). The number of platelets per unit of blood was also significantly correlated with the number of days of lithium treatment. However, the increase in the number of platelets in lithium-treated patients was not correlated with the increase in MAO activity and thus appears not to account for it. These results indicate that studies relating platelet MAO activity to psychiatric diagnosis should be interpreted cautiously if patients are receiving lithium carbonate.

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