Biomedical subjects

G Gerra

Publications and source records attributed to G Gerra.

At least 37 records · Page 2Linked to original sources

PubMed2001

Lofexidine versus clonidine in rapid opiate detoxification.

The aim of the present study is to evaluate lofexidine and clonidine, in an accelerated opiate detoxification procedure (3 days), without anaesthesia. Forty heroin-dependent individuals were detoxified, evaluating withdrawal symptoms, craving levels, mood changes, urine toxicologic screens, and dropout during therapy with either (1) clonidine, oxazepam, baclofen, and ketoprofene, with naloxone and naltrexone for 3 days (20 subjects) or (2) lofexidine, oxazepam, baclofen, and ketoprofene with naloxone and naltrexone for 3 days (20 subjects). Both clonidine and lofexidine rapid detoxifications were found effective. The subjects treated with lofexidine showed significantly lower levels of withdrawal symptoms, fewer mood problems, less sedation and hypotension. No significant differences in craving levels, morphine metabolites in urine, or dropout rate were evidenced between the two groups. The early use of naltrexone during detoxification in combination with either alpha-2-agonist facilitated the acceptance for long-term naltrexone treatment. Lofexidine appeared to be more useful than clonidine in a 3-day accelerated opiate detoxification, not only to counteract withdrawal symptoms, but also in the treatment of dysphoria and mood changes. Because lofexidine does not produce hypotension, safe outpatient treatment, without hospital support, could be possible.

Adult↗

PubMed2001

Experimentally induced aggressive behavior in subjects with 3,4-methylenedioxy-methamphetamine ("Ecstasy") use history: psychobiological correlates.

PURPOSE: Objective measures of experimentally induced aggressiveness were evaluated in 12 male 3,4-methylenedioxy-methamphetamine (MDMA, "Ecstasy") users, in comparison with 20 healthy male subjects. METHODS: All the subjects were preliminarily submitted to DSM-IV interviews and Buss-Durkee Hostility Inventory (BDHI). During a laboratory task, the Point Subtraction Aggression Paradigm (PSAP), subjects earned monetary reinforcers with repeated button presses, and were provoked by the subtraction of money that was attributed to a fictitious other participant. Subjects could respond by ostensibly subtracting money from the fictitious subject (the aggressive response). Escape responses were also possible protecting the counter from monetary subtractions. RESULTS: Money-earning responses were not different in Ecstasy users and controls; aggressive responses were significantly higher in Ecstasy users in comparison with control subjects (F=20.74, P<.001). Baseline adrenocorticotropic hormone (ACTH) and cortisol (CORT) levels were higher in Ecstasy users than in controls. No difference was found in norepinephrine (NE) and epinephrine (EPI) basal levels of the two groups. During the experimentally induced aggressiveness, plasma ACTH concentrations increased significantly less and NE and EPI levels, together with heart rate (HR), increased significantly more in Ecstasy users than in healthy subjects. Despite ACTH-blunted responses, CORT did not increase differently from controls in Ecstasy users. PSAP aggressive responses positively correlated with catecholamines and CORT changes, BDHI Direct Aggression and Irritability scores, both in Ecstasy users and controls. A significant correlation was found between Ecstasy exposure extent and aggressive responses (r=.78, P<.001). IMPLICATIONS: Our findings suggest that Ecstasy users have higher outward-directed aggressiveness than healthy subjects. Aggressiveness in MDMA subjects seems to be associated more with MDMA pharmacological effects than with personality traits: Nevertheless, a premorbid psychobiological proneness to aggressive behavior cannot be excluded. Increased catecholamines reactivity, basal hypothalamus-pituitary-adrenal (HPA) axis hyperactivity, and blunted ACTH responses could be due to MDMA action on monoaminergic pathways and adrenal function.

Adolescent↗

PubMed2000

Neuroendocrine correlates of depression in abstinent heroin-dependent subjects.

The functions of the central alpha-adrenergic, serotoninergic and dopaminergic systems were investigated in 28 heroin-dependent subjects 6-8 weeks after detoxification, and in 22 healthy control subjects (group C). Fourteen heroin-dependent subjects with depressive comorbidity (group A), and 14 heroin-dependent subjects without other Axis I and II pathologies (group B) were included among abstinent substance abusers. Norepinephrine (NE) function was evaluated by growth hormone (GH) responses to acute stimulation with clonidine (clon); serotonin (5-HT) function by prolactin (PRL) and cortisol (CORT) responses to acute stimulation with D-fenfluramine (D-fen) and dopamine (DA) function by GH and PRL responses to acute administration of bromocriptine (brom). Central NE activity, as measured by the GH-clon test, seems to be well preserved both in A and B subjects. PRL and CORT responses to D-fen were significantly blunted both in A subjects and in B subjects, in comparison with control subjects (C); the PRL response in A subjects was significantly lower than in B subjects. The DA system of B subjects was found unimpaired; in contrast, a significantly higher GH response to brom in A subjects (depressed) could express D2 post-synaptic receptor hypersensitivity and, therefore, decreased pre-synaptic DA release. In sum, the study of central monoamine function revealed an alteration only of the 5-HT system in detoxified heroin-dependent subjects without psychiatric comorbidity, which might be a trait character of these subjects, possibly involved in the pathogenesis of the disorder. A more significant impairment of 5-HT function and the hypersensitivity of post-synaptic DA receptors in A subjects suggests that specific biological correlates of psychiatric comorbidity may characterize substance abuser subtypes.

Adrenergic alpha-Agonists↗

PubMed2000

Long-lasting effects of (+/-)3,4-methylenedioxymethamphetamine (ecstasy) on serotonin system function in humans.

BACKGROUND: Fifteen (+/-)3,4-Methylenedioxymethamphetamine (MDMA) users, who did not show other drug dependencies or prolonged alcohol abuse, and 15 control subjects were included in the study. METHODS: Prolactin (PRL) and cortisol (CORT) responses to the serotonergic agonist d-fenfluramine (D-fen), clinical psychobehavioral changes, and psychometric measures were evaluated 3 weeks and then 12 months after MDMA discontinuation. RESULTS: MDMA users showed significantly reduced PRL and CORT responses in comparison with control subjects at 3 weeks (respectively, p < .001; p < .005). The responses of PRL to D-fen were unmodified at 12 months after prolonged abstinence and were significantly reduced in comparison with controls (p < .001). In contrast, CORT responses in MDMA users were restored after 12 months of abstinence, with significantly higher responses to D-fen, in comparison with 3-week responses (p < .05). MDMA users' high scores on the Novelty Seeking (NS) scale on the Tridimensional Personality Questionnaire (TPQ) appeared unchanged by long-term abstinence. In contrast, Buss Durkee Hostility Inventory (BDHI) (Buss and Durkee 1957) direct and guilt scores decreased significantly after 12 months of abstinence. PRL AUCs at 12 months were inversely correlated with the measures of MDMA exposure (r = -.538). CONCLUSIONS: Our data indicate long-lasting 5-HT system impairment in abstinent MDMA users although the hypothesis of serotonergic changes attributable to a premorbid condition cannot be excluded. CORT restored responses to D-fen at 12 months, and the correlation of neuroendocrine changes with MDMA exposure suggest that the neuroendocrine impairment may be due to a partially reversible neurotoxic action of MDMA on the human brain.

Adolescent↗

PubMed2000

Neuroendocrine correlates of temperamental traits in humans.

Studies investigating temperament traits in humans and their biological correlates have found high levels of novelty seeking (NS) linked with dopaminergic system changes, and particularly a deficit of dopamine transporter. Harm avoidance and reward dependence, on the other hand, appeared to be associated, respectively with serotonin and noradrenaline changes. In the present study, we have investigated the dopaminergic (DA), serotonergic (5-HT), and noradrenergic (NE) functions in healthy volunteers by challenging the monoamine systems with the DA agonist bromocriptine, the 5-HT agonist D-fenfluramine, and the NE agonist clonidine, respectively. Parallel to this investigation, we examined the temperament traits of our subjects by measuring NS, harm avoidance (HA) and reward dependence (RD) using the 'Three-dimensional Personality Questionnaire' (TPQ). The aims of the study were to see whether or not the monoamine functions were correlated with temperament traits. Bromocriptine challenge induced a significant GH increase and a significant suppression of PRL. D-fenfluramine test significantly increased PRL and cortisol plasma levels and Clonidine test induced a significant rise in GH values. NS scores showed a significant direct correlation with brom-stimulated GH values (r=0.426, P<0.05) and a significant inverse correlation with brom-inhibited PRL values (r=-0.498, P<0.01). HA scores correlated significantly with D-fen-stimulated PRL and CORT AUCs, (PRL: r=0.424, P<0.05; CORT: r=0. 595, P<0.005). RD scores correlated positively with clon-stimulated GH values (r=0.55; F=8.6; P<0.01) and negatively with brom-inhibited-PRL AUCs (r=-0.439, P<0.05). Our data support Cloninger theory concerning the biological correlates of temperamental traits, and evidence the link between the neuroendocrine responses to dynamic challenges and stable temperament features.

Adrenergic alpha-Agonists↗

PubMed2000

Rapid opiate detoxication in outpatient treatment: relationship with naltrexone compliance.

A variety of detoxification methods have been utilized for the treatment of heroin withdrawal before individuals begin long-term opiate-free and naltrexone programs. While methadone in decreasing doses is still widely used for detoxication procedures, rapid and ultrarapid protocols including clonidine and opiate receptors antagonists have been proposed. This study compares the efficacy of different detoxification methods and investigates possible changes in naltrexone compliance. Ninety-eight heroin-addicted individuals were studied to evaluate withdrawal symptoms, craving, mood, urine toxicologic screens, and drop-out rate during therapy with: Group A: clonidine only (5 days); Group B: clonidine, oxazepam, baclofen, and ketoprofene with naloxone and naltrexone (2 days); and Group C: methadone in decreasing doses (10 days). Naltrexone compliance and relapse rates were evaluated during a 6-month follow-up period. Rapid detoxification with opiate antagonists (Group B) induced slight and transient withdrawal symptoms, and resulted in a significantly lower percentage of heroin catabolites in urine controls during the detoxification procedure, lower negative and positive craving, less mood problems, and higher compliance in extended naltrexone treatment. In comparison with clonidine only (Group A) and methadone (Group C), the early use of naltrexone during detoxification in combination with benzodiazepines and clonidine facilitated extended naltrexone acceptance and improved the recovery outcome in outpatients.

Adolescent↗

PubMed2000

Neuroendocrine correlates of temperament traits in abstinent opiate addicts.

PURPOSE: Studies investigating temperament traits of drug abusers and their biological correlates have disclosed high rates of novelty seeking (NS) in opiate addicts, possibly based on dysfunctions of the dopaminergic (DA) system. The aims of the present study were to see whether or not the monoamine functions were impaired in detoxified addicts and whether or not these alterations were correlated with temperament traits, given the possibility that impairment of the biological and temperament parameters might be responsible for the development of addiction. METHODS: We have investigated the DA, serotonergic (5-HT), and noradrenergic (NE) functions in 22 abstinent heroin addicts and 22 healthy controls by challenging the monoamine systems with the DA agonist bromocriptine (brom), the 5-HT agonist D-fenfluramine (D-fen), and the NE agonist clonidine (clon), respectively. We examined the temperament traits by measuring NS, harm avoidance (HA), and reward dependence (RD) using the "Three-Dimensional Personality Questionnaire" (TPQ). RESULTS: Addicts showed higher than normal NS scores at TPQ blunted 5-HT function, and normal DA and NE activities, in response to the neuroendocrine challenges. NS correlated negatively with the DA function in both addicts and controls, and negatively with the 5-HT function only in addicts. HA correlated positively with 5-HT function in controls but not in addicts. IMPLICATIONS: The impairment in 5-HT function observed in heroin addicts and the changes in the biological correlates of temperamental traits could increase the proneness to addiction and possible comorbid psychiatric disorders.

Adult↗

PubMed2000

Neuroendocrine responses to psychological stress in adolescents with anxiety disorder.

Neurotransmitter-neuroendocrine and cardiovascular responses to the administration of a psychologically stressful mixed-model test (Mental Arithmetic, Stroop Color Word Interference Task, Trier Social Stress Test) were examined in 20 male peripubertal subjects affected by anxiety disorder (group A: 14 with generalized anxiety disorder, 6 with generalized anxiety disorder and separation anxiety disorder) and 20 junior school adolescents, matched for age, without overt psychological disorders (group B). Plasma levels of norepinephrine (NE), epinephrine (EPI), adrenocorticotropic hormone (ACTH), beta-endorphin (beta-EP), cortisol (CORT), growth hormone (GH), prolactin (PRL) and testosterone (Te) were measured immediately before the beginning of the tests and 30 min later at their end. Mean prestress values of GH, PRL, beta-EP and ACTH were significantly higher in anxious subjects than in controls. There was no difference in NE, EPI, CORT and Te prestress levels in the two groups. After the psychological stress session NE, GH and Te concentrations increased significantly in anxious subjects (A), but not in controls. In contrast, beta-EP and PRL decreased significantly during the psychological stress session in anxious subjects, and were unaffected by stress in the subjects without anxiety. No significant changes were found in ACTH, CORT and EPI during the challenge either in anxious subjects or in controls, which may be attributed to the late time of poststress blood sampling. In contrast to controls, heart rate and systolic blood pressure increased significantly in anxious subjects after psychological stress testing. Our data support the hypothesis that the hyperactivity of the noradrenergic system in response to stress is associated with anxiety disorders in adolescents and might influence the responses of GH and Te. High prestress basal values of stress hormones seem to be induced in anxious subjects by the anticipation of the task or by a persistent hyperactivity of the noradrenergic system. Further studies are needed to investigate in more detail the involvement of the HPA axis in anxious adolescents by a more refined resolution of time points of blood sampling.

Adolescent↗

PubMed2000

[Psychobiologic risk factors and vulnerability to psychostimulants in adolescents and animal models].

Adolescent↗

PubMed1999

Determination of catecholamines in human plasma by high-performance liquid chromatography with electrochemical detection.

In the present study, assays were improved for the determination of catecholamines in human plasma. High-performance liquid chromatography with electrochemical detection was employed for quantitative analysis. The influence of various parameters on chromatographic performance, such as the composition and the pH of the mobile phase, and the detection potential, was investigated. An accurate solid-phase extraction procedure, after catecholamine complexation with diphenylborate, was developed. The efficiency yield for all catecholamines was in the range 92-98%. Relative standard deviation values for repeatability and for intermediate precision were less than 2% and 3%, respectively, for all three analytes.

Calibration↗

PubMed1999

Psychobiological risk factors for vulnerability to psychostimulants in human adolescents and animal models.

Adolescence is associated with an increased risk of developing drug abuse/dependence. During this ontogenetic phase, brain and hormonal systems are still undergoing crucial maturational rearrangements, which take place together with significant modifications in psychosocial development. However, the neurohormonal and behavioral facets of adolescence have been poorly investigated in relation to the vulnerability to psychostimulants such as MDMA ("Ecstasy") and amphetamine (AMPH). Novelty-seeking, a temperamental/behavioral trait that is typical of this age period, might substantially contribute to both psychological and psychobiological vulnerability. In humans, an elevated score of novelty-sensation seeking and a derangement of monoaminergic function were both associated with late adolescence MDMA users compared to controls. In animal models of periadolescence, the search for novel stimuli and sensations actually shares a common neurobiological substrate (the reward-related brain mesolimbic pathways) with psychostimulants. The present review summarises recent work in mice, which indicates that periadolescent subjects are characterized by an unbalanced and "extremes-oriented" behavior and by elevated novelty-seeking compared to adults. Repeated and intermittent administration of cocaine or AMPH was associated with the development of a prominent locomotor sensitization in periadolescents, which failed to exhibit the marked sensitization of the stereotyped behavioral syndrome--possibly associated with poor welfare--that was typical of adults. A unique profile of integrated behavioral and physiological hyporesponsivity to both forced novelty and acute AMPH administration during periadolescence was also found. As a whole, these results, together with previous work on this topic, suggest that periadolescents may be more "protected" from AMPH-related aversive properties, and perhaps more vulnerable to the experience of internal states of reward, than older animals. Thus, the present animal model of adolescence seems to represent a reliable and useful method for the investigation of vulnerability to a variety of habit-forming agents or emotional experiences whose positive reinforcing properties may rely on common neurobiological substrates. A deeper understanding of psychostimulant effects during adolescence on the complex interaction between genetic, neurobiologic, psychosocial, and environmental factors will lead to earlier and more effective prevention and treatment.

Adolescent↗

PubMed1999

Neurotransmitters, neuroendocrine correlates of sensation-seeking temperament in normal humans.

Correlations between sensation-seeking (SS) personality dimension and plasma concentrations of norepinephrine (NE), epinephrine, and NE-dependent testosterone (T), cortisol and prolactin (PRL) were studied in 74 physically and psychologically healthy male volunteers, in order to see whether or not the noradrenergic system is involved in the modulation of this personality trait. Novelty-seeking scores by the Temperament and Character Inventory and SS scores on a Visual Analog Scale were positively correlated with plasma NE, T and PRL levels, suggesting that NE and the downstream cascade of NE-dependent hormones, together with other monoaminergic changes, might be responsible for the development and the degree of this temperamental character.

Adult↗

PubMed1999

Experimentally induced aggressiveness in adult children of alcoholics (ACOAs): preliminary behavioral and neuroendocrine findings.

OBJECTIVE: This study was conducted to determine the nature of the reaction of nonalcoholic adult children of alcoholic (ACOA) fathers to the experimental induction of aggression. Of particular interest was the relationship between biochemical factors and personality traits during a stressful event experienced by persons at risk for alcoholism. METHOD: Aggression was induced by a modified free-operant procedure in 14 ACOA and 14 non-ACOA subjects between 18 and 19 years of age with men and women represented in equal numbers. Neurotransmitter-hormonal assays from blood drawn immediately before, and 20 and 30 minutes after, starting the test included norepinephrine (NE), epinephrine (EPI), prolactin (PRL), growth hormone (GH) and cortisol (Cort). Personality traits were assessed by the Minnesota Multiphasic Personality Inventory (MMPI) Tridimensional Personality Questionnaire (TPQ) and the Buss-Durkee Hostility Inventory (BDHI). RESULTS: During the aggression induction session, ACOAs gained (F = 4.6, 1/13 df, p < .05) and subtracted (F = 9.2, 1/13 df, p < .005) significantly less money than non-ACOAs, evidence of lower outward-directed aggressiveness among ACOAs. Higher baseline plasma levels of Cort (F = 9.8, 1/13 df, p < .01) and PRL (F = 4.0, 1/13 df, p < .05) and decreased NE (F = 8.5, 1/13 df, p < .005) and GH (F = 10.9, 1/13 df, p < .001) responses during the experimental session were observed. On personality measures ACOAs scored higher than non-ACOAs on MMPI hysteria (F = 10.8, 1/13 df, p < .005), hypochondria (F = 20.1, 1/13 df, p < .001) and paranoia (F = 4.7, 1/13 df, p < 0.5) subscales, on the TPQ reward dependence (F = 10.9, 1/13 df, p < .005) subscale and on BDHI guilt (F = 15.7, 1/13 df, p < .001) and resentment (F = 6.4, 1/13 df, p < .05) subscales. CONCLUSION: These findings, preliminary in nature, support a hypothesis of inhibition of state and trait aggression in ACOAs in association with monoaminergic and endocrine changes.

Adolescent↗

PubMed1998

Regional cerebral blood flow and comorbid diagnosis in abstinent opioid addicts.

Studies using single photon emission computed tomography (SPECT) have found low cerebral blood flow (CBF) in frontal and parietal cortices in patients with chronic opiate dependence. In the present study, SPECT with 99mTc-HMPAO as tracer was used to compare 27 detoxified opiate addicts with nine healthy control subjects. All the subjects were evaluated with clinical psychiatric (DSM-IV), psychometric and neuropsychological measures. Compared with normal control subjects, the addicts showed a non-significant reduction of whole brain perfusion values. Significant hypoperfusion in the right frontal and left temporal lobes was found in addicts with comorbid depression, and a significant decrease in CBF in the right frontal lobe was observed in those with antisocial tendencies. A significant negative correlation emerged between Depression subscale scores on the Minnesota Multiphasic Personality Inventory and left temporal CBF in the patients. No significant correlations were found, however, between measures of cognition and CBF in opiate addicts. The asymmetrical findings in CBF that characterized the addicts relative to normal control subjects may be more closely related to mood and behavioral traits than to substance abuse, per se.

Adult↗

PubMed1998

GABAergic function in detoxified heroin addicts: relationship to anxiety disorders.

The function of the GABAergic system was examined in 20 subjects with heroin dependence and abuse, 2 months after detoxification, and in 10 healthy volunteers, by measuring the growth hormone (GH) response to a challenge with the GABA B receptor agonist baclofen. Ten heroin addicts had comorbid anxiety disorder (Group A), while the other ten had heroin addiction uncomplicated by Axis I and II psychopathologies (Group B). GH responses to baclofen stimulation of Group A patients were significantly blunted, while those of Group B subjects did not differ from responses of healthy volunteers. Our data show that the function of the GABAergic system is impaired only in heroin addicts with comorbid anxiety disorders (anxious cluster), suggesting that the GABA system is not persistently influenced by prolonged exposure to opioid receptor stimulation.

Adult↗

PubMed1998

Neurotransmitter-hormonal responses to psychological stress in peripubertal subjects: relationship to aggressive behavior.

The relationship between different degrees of normal aggressiveness (low, medium, high) and neurotransmitter-neuroendocrine responses to the administration of psychologically stressful tests (Mental Arithmetic, Stroop Color Word Interference task, Trial Social Stress test) was examined in thirty male peripubertal junior school adolescents. Plasma concentrations of norepinephrine (NE), epinephrine (EPI), ACTH, cortisol (CORT), growth hormone (GH), prolactin (PRL) and testosterone (T) were measured immediately before the beginning of the tests and at their end, 30 min later. High-normal aggressiveness have been found associated with significantly higher basal concentrations of NE, ACTH, PRL, and T and with a significant increase of GH responses to the stressful stimuli.

Adolescent↗

PubMed1998

Neuroendocrine responses of healthy volunteers to 'techno-music': relationships with personality traits and emotional state.

A variety of studies reported psychological and physiological effects of music. Different types of music have been found to induce different neuroendocrine changes. The aim of the present experiment was to investigate the possible combination of emotional and endocrine changes in response to techno-music and to define personality variables as predictors of respective changes. Sixteen psychosomatically healthy subjects (18- to 19-year-olds, eight males and eight females) were exposed, in random order, to techno-music or to classical music (30 min each). Plasma norepinephrine (NE), epinephrine (EPI), growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH) cortisol (CORT), beta-endorphin (beta-EP) concentrations and changes of emotional state were measured in basal conditions and after the experimental trials with two different types of music. Techno-music was associated with a significant increase in heart rate, systolic blood pressure and significant changes in self-rated emotional states. A significant increase was observed in beta-EP, ACTH, NE, GH and CORT after listening to techno-music. Classical music induced an improvement in emotional state, but no significant changes in hormonal concentrations. No differences between male and female subjects' responses to music have been found. Plasma levels of PRL and EPI were unaffected by techno- and classical music. Changes in emotional state and NE, beta-EP and GH responses to techno-music correlated negatively with harm avoidance scores and positively with the novelty-seeking temperament score on the Cloninger scale. Listening to techno-music induces changes in neurotransmitters, peptides and hormonal reactions, related to mental state and emotional involvement: personality traits and temperament may influence the wide inter-individual variability in response to music.

Adolescent↗

PubMed1998

Serotonergic function after (+/-)3,4-methylene-dioxymethamphetamine ('Ecstasy') in humans.

(+/-)3,4-Methylene-dioxymethamphetamine (MDMA, or 'Ecstasy') effects on serotonin system function and behaviour in humans are unclear. Fifteen MDMA users, who did not have other drug dependencies or alcohol abuse, and had not used other drugs for prolonged periods, and 15 control individuals were included in a study to assess the biological and psychological changes after chronic use of MDMA. Prolactin and cortisol responses to D-fenfluramine challenge, clinical psychobehavioural changes, personality characteristics, including mood, aggressiveness and temperamental aspects, were evaluated 3 weeks after MDMA discontinuation. MDMA users had significantly reduced prolactin and cortisol responses in comparison with control individuals (p < 0.001 and p < 0.005, respectively). Dysphoria and mood changes were exhibited in seven individuals, tiredness in five and sensation-seeking behaviour in twelve at the clinical evaluation. Significantly higher scores were found in MDMA individuals than in control individuals for Minnesota Multiphasic Personality Inventory subscale for Depression, for Buss Durkee Hostility Inventory direct and guilt subscales, for Hamilton Depression Rating Scale and for novelty-seeking Tridimensional Personality Questionnaire subscale. Prolactin responses to D-fenfluramine stimulation area under the curve among MDMA users were negatively correlated with direct aggressiveness scores for Buss Durkee Hostility Inventory; a negative correlation between prolactin responses and novelty-seeking scores was also evidenced among MDMA users. These data suggest an association between serotonin system impairment and MDMA use in humans; in interpretation of these results, the possibility that serotonin deficit in MDMA individuals was partially related to a premorbid condition, in relationship with novelty-seeking behaviour and mood disorders, can not be excluded.

Adolescent↗