RESUMO
AIMS: The aim of the study was to analyze independent and potential interactive effects of age at drinking onset and family history of alcohol abuse on subsequent patterns of alcohol drinking, alcohol-related problems and substance use. METHODS: Participants were college students (60.3% females, mean age = 20.27 ± 2.54 years) from the city of Córdoba, Argentina. Several measures were used to assess alcohol, tobacco and drug use. The Spanish version of the Brief Young Adult Alcohol Consequences Questionnaire was used to assess alcohol-related problems. Factorial analyses of variance, or its non-parametric equivalent, were performed to explore differences in substance use behaviors and alcohol-related problems in subjects with early or late drinking onset and with or without family history of alcohol abuse. Chi-square tests were conducted to analyze the association between these two risk factors and categorical measures of alcohol, tobacco and drug use. RESULTS: Early onset of drinking was associated with amount of consumption of alcohol including up to hazardous levels, as well as tobacco and drug use. However, the frequency of alcohol problems and frequency of episodes of alcohol intoxication were only related to age of onset in those with a positive family history of alcohol problems. CONCLUSION: Delaying drinking debut is particularly important in the prevention of future alcohol problems in those adolescents who have a family history of such problems.
Assuntos
Consumo de Bebidas Alcoólicas/genética , Consumo de Bebidas Alcoólicas/psicologia , Saúde da Família , Transtornos Relacionados ao Uso de Substâncias/genética , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adolescente , Fatores Etários , Idade de Início , Consumo de Bebidas Alcoólicas/epidemiologia , Intoxicação Alcoólica/epidemiologia , Intoxicação Alcoólica/genética , Intoxicação Alcoólica/psicologia , Antecipação Psicológica , Argentina/epidemiologia , Atitude Frente a Saúde , Feminino , Humanos , Comportamento Impulsivo/epidemiologia , Comportamento Impulsivo/genética , Comportamento Impulsivo/psicologia , Masculino , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Inquéritos e Questionários , Universidades , Adulto JovemRESUMO
BACKGROUND: Impulsivity is a multidimensional construct which has been associated with dopaminergic neurotransmission. Nonetheless, until this moment, few studies addressed the relationship between different types of impulsivity and the single nucleotide polymorphism caused by a substitution of valine (val) with methionine (met) in the 158 codon of the Catechol-o-Methyltransferase gene (COMT-val158met). The present study aimed to investigate the association between val158met COMT polymorphism and impulsive behavior measured by two neuropsychological tests. METHODOLOGY/PRINCIPAL FINDINGS: We administered two neuropsychological tests, a Continuous Performance Task and the Iowa Gambling Task were applied to 195 healthy participants to characterize their levels of motor, attentional and non-planning impulsivity. Then, subjects were grouped by genotype, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional and motor impulsivity. Those participants who were homozygous for the met allele performed worse in the Iowa Gambling Task than val/val and val/met subjects. CONCLUSIONS/SIGNIFICANCE: Our results suggest that met allele of val158met COMT polymorphism is associated with poor performance in decision-making/cognitive impulsivity task. The results reinforce the hypothesis that val and met alleles of the val158met polymorphism show functional dissociation and are related to different prefrontal processes.
Assuntos
Catecol O-Metiltransferase/genética , Jogo de Azar/genética , Comportamento Impulsivo/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Atenção , Códon , Feminino , Genótipo , Humanos , Masculino , Metionina/genética , Pessoa de Meia-Idade , Testes Neuropsicológicos , Valina/genética , Adulto JovemRESUMO
Dopamine (DA) is considered to be an important neurotransmitter in the control of impulsive behavior, however, its underlying mechanisms have not been fully elucidated. Catechol-O-methyltransferase (COMT) is a key enzyme in the catabolism of DA within the prefrontal cortex (PFC) and has been suggested to play a role in the mediation of impulsive behavior. The COMT single nucleotide polymorphism (SNP) rs4680 (Val158Met) Met allele has been shown to decrease COMT enzyme activity and is associated with improved PFC cognitive function (intelligence and executive functions). Studies have associated the rs4680 genotype with impulsivity as a symptom in attention deficit hyperactivity disorder and substance abuse. However, only a few studies have assessed the effects of rs4680 on impulsiveness in healthy subjects, the results of which remain controversial. The Barratt Impulsiveness Scale (BIS-11) was applied to 82 healthy volunteers (including 42 females) who were genotyped for COMT rs4680. Subjects carrying the Met/Met genotype scored higher for the BIS-11 second-order factor Non-planning than carriers of the Val/Val genotype. No interaction between gender genotype was detected. Age, gender and education had no effect on the results. The COMT rs4680 Met/Met genotype was associated with higher impulsivity on the BIS-11 second-order factor Non-planning. These results suggest that COMT enzyme activity may be important in the regulation of impulsiveness among young adults. Further studies involving larger samples should be conducted to confirm the results of the present study.
Assuntos
Catecol O-Metiltransferase/genética , Dopamina/metabolismo , Estudos de Associação Genética , Comportamento Impulsivo/genética , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/genética , Transtorno do Deficit de Atenção com Hiperatividade/metabolismo , Transtorno do Deficit de Atenção com Hiperatividade/patologia , Dopamina/genética , Feminino , Voluntários Saudáveis , Humanos , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiologia , Adulto JovemRESUMO
BACKGROUND: Suicide behavior is very frequent in Bipolar Disorder (BD) and they are both closely associated with impulsivity. Furthermore they are, impulsivity, BD and suicide behavior, associated with serotonergic function, at least partially, under genetic determinism and somewhat associated with the serotonin transporter gene polymorphism, the 5-HTTLPR. We aimed to assess different impulsivity components in BD sub-grouped by suicidal attempt and healthy controls. We hypothesized that the non-planning/cognitive impulsivity, could be more closely associated with suicidal behavior. We further associated 5-HTTLPR genotypes with neuropsychological results to test the hypothesis that this polymorphism is associated with cognitive impulsivity. METHOD: We assessed 95 euthymic bipolar patients sub-grouped by suicidal attempt history in comparison with 94 healthy controls. All subjects underwent a laboratory assessment of impulsivity (Continuous Performance Test and Iowa Gambling Test). Furthermore the genotyping of 5-HTTLPR was performed in all subjects. RESULTS: We found that bipolar patients are more impulsive than healthy controls in all impulsivity dimensions we studied. Furthermore bipolar patients with a suicide attempt history have a greater cognitive impulsivity when compared to both bipolar patients without such a history as well when compared to healthy controls. No association was found between 5-HTTLPR genotypes and neuropsychological measures of impulsive behavior. LIMITATIONS: The sample studied can be considered small and a potentially confounding variable - medication status - was not controlled. CONCLUSION: A lifetime suicide attempt seems associated with cognitive impulsivity independently of the socio-demographic and clinical variables studied as well with 5-HTTLPR genotype. Further studies in larger samples are necessary.
Assuntos
Transtorno Bipolar/genética , Transtorno Bipolar/psicologia , Polimorfismo Genético , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Suicídio/psicologia , Adulto , Transtorno Ciclotímico/genética , Feminino , Genótipo , Humanos , Comportamento Impulsivo/genética , Iowa , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Ideação Suicida , Tentativa de Suicídio/psicologiaRESUMO
BACKGROUND: Impulsivity has been associated with serotonergic system functions. However, few researchers have investigated the relationship between a polymorphism in the promoter of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. The aim of this study was to investigate the relationship between a polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) and the different components of impulsivity in a non-clinical population. METHODOLOGY/PRINCIPAL FINDINGS: We administered two neuropsychological tests, the Continuous Performance Task and the Iowa Gambling Task, to 127 healthy participants to measure their levels of motor, attentional and non-planning impulsivity. Then, these participants were grouped by genotype and gender, and their scores on impulsivity measures were compared. There were no significant differences between group scores on attentional, motor and non-planning impulsivity. CONCLUSIONS/SIGNIFICANCE: Our results suggest that 5-HTTLPR genotype is not significantly associated with subsets of impulsive behavior in a non-clinical sample when measured by neuropsychological tests. These findings are discussed in terms of the sensitivity of neuropsychological tests to detect impulsivity in a non-clinical population and the role of gender and race in the relationship between the 5-HTTLPR and impulsivity.
Assuntos
Comportamento Impulsivo/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Adolescente , Adulto , Feminino , Frequência do Gene , Genótipo , Humanos , Comportamento Impulsivo/etnologia , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , População , Grupos Raciais/genética , Grupos Raciais/psicologia , Caracteres Sexuais , Adulto JovemRESUMO
BACKGROUND: Disturbances in central serotonin function have been implicated in impulsive and aggressive behavior. A deletion/insertion polymorphism within the 5-HT transporter promoter gene (5-HTTLPR) is thought to be associated with disturbed impulse control, anxiety, and depression. The serotonin transporter (5-HTT) is the primary action site for selective serotonin reuptake inhibitors (SSRIs). Several studies of major depression have shown that the l allele of 5-HTTLPR is associated with better SSRI antidepressant effects than the s allele. METHODS: This study investigates the association between response of impulsivity to treatment with fluoxetine and 5-HTTLPR polymorphism in 49 personality disordered patients. Additionally, we studied TPH1, 5HT1B and 5HT2C receptor polymorphisms as predictors of response in this population. RESULTS: Results reveal that patients with the l/l genotype of 5-HTTLPR had a significantly better response to fluoxetine when compared to s allele carriers, as evaluated on the basis of total (P<0.05) and Aggression subscale (P<0.01) Overt Aggression Scale Modified-score percentage change. There were no significant associations between fluoxetine response and TPH1 (A218C) (-6525 A>G) (-5806 G>T), HTR1B (G861C) and HTR2C (G68C) genotype groups. CONCLUSION: This is the first study assessing the association between these polymorphisms and anti-impulsive response to fluoxetine in personality disorder. As the s genotype is associated with a poorer selective serotonin reuptake inhibitors response in major depression, bulimia nervosa and borderline personality disorder, it could represent a common biological background for SSRI response.
Assuntos
Agressão , Fluoxetina/uso terapêutico , Comportamento Impulsivo/genética , Transtornos da Personalidade/genética , Polimorfismo Genético/genética , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Adolescente , Adulto , Idoso , Agressão/efeitos dos fármacos , Agressão/fisiologia , Alelos , Feminino , Genótipo , Humanos , Comportamento Impulsivo/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Transtornos da Personalidade/tratamento farmacológico , Escalas de Graduação Psiquiátrica , Adulto JovemRESUMO
The enzyme monoamine oxidase A (MAO A) plays an important role in the metabolism of neurotransmitters. The MAOA gene presents several polymorphisms, including a 30-bp VNTR in the promoter region (MAOA-uVNTR). Alleles with 3.5 and 4 repeats are 2-10 times more efficient than the 3-repeat allele. Several studies have shown an association between the 3-repeat allele and a cluster of externalizing behaviors including alcoholism, antisocial personality, and impulsivity. The objective of the present study is to replicate in a different culture the associations between the MAOA-uVNTR with alcoholism and other phenotypes. The sample comprises 125 Brazilian alcoholics of European descent and 235 controls. The results suggest that the 3-repeat allele is associated to: (1) alcohol dependence (P < 0.05); (2) an earlier onset of alcoholism (P < 0.01); (3) comorbid drug abuse among alcoholics (P < 0.05); and (4) a higher number of antisocial symptoms (P < 0.02). Our results confirmed previous reports showing an association of the low activity 3-repeat allele of MAOA-uVNTR polymorphism with substance dependence and impulsive/antisocial behaviors. These findings in a different culture further support the influence of the MAOA-uVNTR in psychiatric disorders.
Assuntos
Repetições Minissatélites/genética , Monoaminoxidase/genética , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Alcoolismo/genética , Alcoolismo/psicologia , Alelos , Análise de Variância , Brasil , Frequência do Gene , Genótipo , Humanos , Comportamento Impulsivo/genética , Comportamento Impulsivo/psicologia , MasculinoRESUMO
O suicídio é um sério problema de saúde pública, principalmente em países desenvolvidos, onde as altas taxas de suicídio entre jovens adultos do sexo masculino fazem com que este seja uma das principais causas de morte e de anos potenciais de vida perdidos. A etiologia do suicídio é certamente complexa, com diveros fatores contribuindo para a predisposição a este evento. Entre estes se encontram os fatores genéticos. Nos últimos anos, diversos estudos genético-epidemiológicos têm consistentemente sugerido que o componente genético é significativo. Entretanto, o modo exato através do qual os genes aumentam a predisposição de certos indivíduos a cometer o suicídio é ainda desconhecido. Há evidência crescente de que os fatores genéticos devem influenciar a predisposição ao suicídio via uma modulação dos comportamentos impulsivo e impulsivo-agressivo. Este artigo revisa e discute os estudos que investigaram fatores genéticos no comportamento suicida, assim como esta relação com os traços impulsivo-agressivos