Effects of acute and chronic methylphenidate administration on beta-endorphin, growth hormone, prolactin and cortisol in children with attention deficit disorder and hyperactivity

The effect of methylphenidate on the dopamine and growth hormone response to exercise in children with attention-deficit hyperactivity disorder

PURPOSE

To assess the growth hormone (GH) and Dopamine (DA) response to exercise in children with attention-deficit hyperactivity disorder (ADHD) with and without methylphenidate (MP). We hypothesized that the GH and DA response to the exercise with MP would be siginicantly lower.

METHODS

Twenty children participated in the study (12 males and 8 females, age range 9-13 years). Ten with ADHD and 10 controls. Participants with ADHD performed an exercise test twice, with and without MP while controls performed one exercise test. Blood samples for GH and DA were collected before, at peak, 30 and 60 min after the end of exercise.

RESULTS

Compared to controls, children with ADHD with and without MP, had a significantly lower GH (P < .002) and DA (P < .01) responses to exercise. In participants with ADHD, a significantly greater GH response (p < .04) to exercise was found when MP administered to the children before exercise, yet this response was still significantly lower than controls.

CONCLUSIONS

GH and DA excretion after an exercise challenge in children with ADHD is impaired. MP slightly attenuates the GH blunted response. This may link ADHD with growth impairment in some children and explain previous findings indicating that the final adult height is usually not compromised in children with ADHD treated with MP. The combined exercise and stimulant treatment therapeutic effects needs to be further explored.

TRIAL REGISTRATION NUMBER

NCT00945971.

Ghrelin regulates hyperactivity-like behaviors via growth hormone signaling pathway in zebrafish (Danio rerio)

INTRODUCTION

Ghrelin is originally identified as the endogenous ligand for the growth hormone secretagogue receptor (GHSR) and partially acts by stimulating growth hormone (GH) release. Our previous studies have identified GHRELIN as a novel susceptibility gene for human attention-deficit hyperactivity disorder (ADHD), and ghrelin-depleted zebrafish (Danio rerio) display ADHD-like behaviors. However, the underlying molecular mechanism how ghrelin regulates hyperactivity-like behaviors is not yet known.

RESULTS

Here, we performed RNA-sequencing analysis using adult ghrelin ^Δ/Δ zebrafish brains to investigate the underlying molecular mechanisms. We found that gh1 mRNA and genes related to the gh signaling pathway were significantly reduced at transcriptional expression levels. Quantitative polymerase chain reaction (qPCR) was performed and confirmed the downregulation of gh signaling pathway-related genes in ghrelin ^Δ/Δ zebrafish larvae and the brain of adult ghrelin ^Δ/Δ zebrafish. In addition, ghrelin ^Δ/Δ zebrafish displayed hyperactive and hyperreactive phenotypes, such as an increase in motor activity in swimming test and a hyperreactive phenotype under light/dark cycle stimulation, mimicking human ADHD symptoms. Intraperitoneal injection of recombinant human growth hormone (rhGH) partially rescued the hyperactivity and hyperreactive-like behaviors in ghrelin mutant zebrafish.

CONCLUSION

Our results indicated that ghrelin may regulate hyperactivity-like behaviors by mediating gh signaling pathway in zebrafish. And the protective effect of rhGH on ghrelin ^Δ/Δ zebrafish hyperactivity behavior provides new therapeutic clues for ADHD patients.

Reduced exercise-induced growth hormone secretion among children with attention-deficit hyperactivity disorder

PURPOSE

Attention-deficit/hyperactivity disorder (ADHD) is typically a chronic, often lifelong condition. Data suggest that ADHD itself and its treatment may be associated with dysregulated growth, including height and BMI. The reason for this association is yet unknown. The objective of this study was to examine differences in growth hormone (GH) response to exercise between children who had received a diagnosis of ADHD and age- and gender-matched controls. We reasoned that the normal increase in circulating GH seen in response to exercise would be blunted in children with ADHD.

METHODS

We recruited 13 treatment-naïve children with newly diagnosed ADHD and 14 age-matched controls (all male) and measured GH response to an exercise test in which the work was scaled to each subject's physical capability.

RESULTS

There was no difference in the peak heart rate achieved during exercise between controls and ADHD participants (196.6 ± 1.5 vs. 196.5 ± 2.1 bpm, respectively) and lactate response to exercise (53.8 ± 5.0 vs. 47.9 ± 3.8 mg/dl, respectively). After exercise, GH increased significantly in the control subjects (p < 0.005), while GH responses were substantially blunted in the ADHD group (p = NS) even though the work performed did not differ from controls.

CONCLUSIONS

Our data suggest that GH excretion after exercise challenge in children with ADHD is impaired. This can be detected using a minimally invasive, nonpharmacologic challenge and may link ADHD with growth impairment in some children.

TRIAL REGISTRATION NUMBER

NCT00945971.

Temperament Dimensions and Awakening Cortisol Levels in Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To investigate whether temperament dimensions, Effortful Control (EC), Surgency-Extraversion (SE), and Negative Affectivity (NA), are associated with attention-deficit/hyperactivity disorder (ADHD) and how they relate to awakening cortisol levels, as a proxy measure of peripheral arousal.

METHODS

Parent-rated temperament and saliva samples were collected from 55 children with ADHD and 65 age-matched controls.

RESULTS

Compared to controls, youths with ADHD showed lower EC, higher NA, and lower awakening cortisol levels but did not differ in SE. Similar findings emerged in dimensional analyses linking temperament traits to inattention and hyperactivity-impulsivity symptoms. The results remained unchanged when controlling for the presence of co-occurring opposition-defiance and anxiety traits, as well as medication status. Temperament dimensions were not associated with cortisol levels.

CONCLUSIONS

Poor temperamental emotional and cognitive self-regulation showed significant associations with ADHD but did not appear to be linked to the under-arousal typically seen in ADHD.

Biosignature of self-injury behaviors in adolescence: Role of β-endorphin in an acute inpatient unit

Self-injurious behavior (SIB) (either non-suicidal self-injury, NSSI; or suicide attempts, SA) is a common reason for adolescent psychiatric emergency hospitalizations. Altered basal serum β-endorphin (BE) levels have been reported in adults with a history of SIB, but information is lacking in adolescents. We analyzed the psychoclinical profile and serum BE level of 39 adolescents admitted to the acute unit at a hospital in Spain due to SIB. The Mean (SD) serum BE level was high (190.53 ± 74.83). Regarding time sequence, the onset age of NSSI and SA were related (p < 0.001). The older the onset age of NSSI, the shorter the transition between NSSI and the onset of SA behavior (p = 0.05), but this difference does not lead the variation of BE (p = 0.81). Patients diagnosed with depression had lower serum BE levels than adolescents with other diagnoses (p = 0.03). Although adolescents who seem to be addicted to SIB had higher levels of BE, this finding was not statistically significant. The relationship between serum BE levels and SIB in adolescents requires further investigation.

The Trend in Morning Levels of Salivary Cortisol in Children With ADHD During 6 Months of Methylphenidate Treatment

OBJECTIVE

To determine the trend in cortisol levels in children with ADHD treated with methylphenidate (MPH) and nontreated healthy controls over a 6-month period.

METHOD

The morning salivary cortisol levels of 50 patients with ADHD (40 boys and 10 girls, mean age = 7.6 years) and 50 age- and gender-matched healthy controls were measured at baseline and at 1, 3, and 6 months from baseline. The neuropsychological performance of the ADHD patients was measured via administration of the Continuous Performance Test.

RESULTS

The cortisol levels of ADHD patients increased significantly after 1 month of MPH treatment before decreasing to an intermediate level, but were significantly positively correlated with neuropsychological performance throughout the 6-month treatment period. The cortisol levels of the controls did not change significantly over the 6-month period.

CONCLUSION

MPH administration appears to positively influence the functioning of the hypothalamic-pituitary-adrenal axis in ADHD patients.

Association Between 5-HTTLPR Polymorphism and Tics after Treatment with Methylphenidate in Korean Children with Attention-Deficit/Hyperactivity Disorder

OBJECTIVES

The purpose of this study is to examine the relationship between 5-HTTLPR polymorphism (44-bp insertion/deletion polymorphism of serotonin transporter gene) and methylphenidate (MPH) treatment response, as well as the association between the adverse events of MPH treatment and 5-HTTLPR polymorphism in children with attention-deficit/hyperactivity disorder (ADHD).

METHODS

A total of 114 children with ADHD (mean age 9.08 ± 1.94 years) were recruited from the child psychiatric clinic in a hospital in South Korea. We have extracted the genomic DNA of the subjects from their blood lymphocytes and analyzed 5-HTTLPR polymorphism of the SLC6A4 gene. All children were treated with MPH for 8 weeks, with clinicians monitoring both the improvement of ADHD symptoms and the side effects. We compared the response to MPH treatment and adverse events among those with the genotype of 5-HRRLPR polymorphism.

RESULTS

There was no significant association between the 5-HTTLPR genotype and the response to MPH treatment in children with ADHD. Subjects with the S/L+L/L genotype tended to have tics and nail biting (respectively, p < 0.001, p = 0.017).

CONCLUSIONS

The results of this study do not support the association between the 5-HTTLPR polymorphism and treatment response with MPH in ADHD. However, our findings suggest the association between 5-HTTLPR polymorphism and the occurrence of tics and nail-biting as an adverse event of methylphenidate. This may aid in our understanding of the genetic contribution and genetic susceptibility of a particular allele in those ADHD patients with tics or nail biting.

Salivary neurosteroid levels and behavioural profiles of children with attention-deficit/hyperactivity disorder during six months of methylphenidate treatment

OBJECTIVE

This prospective study aimed to investigate the relationships between salivary levels of neurosteroids, including dehydroepiandrosterone (DHEA), cortisol, and DHEA/cortisol ratios, and behavioral symptoms in patients with attention-deficit/hyperactivity disorder (ADHD) during treatment with methylphenidate (MPH).

METHODS

Fifty-eight ADHD patients (48 boys and 10 girls) were included in the study initially. Forty patients (mean age: 7.77±1.64 years; 32 boys and 8 girls) who completed the study received treatment with oral MPH with a dose range of 5-15 mg/day (mean dose: 12.47±7.74 mg/day.) for 6 months at the discretion of the psychiatrist. DHEA and cortisol levels were determined from saliva samples collected at 0800 h at baseline and 6 months from baseline. ADHD symptoms were evaluated with the Child Behavior Checklist (CBCL).

RESULTS

Salivary DHEA levels (mean difference=9.05 pg/mL, p=0.027) and DHEA/cortisol ratios (mean difference=32.42, p=0.007) in ADHD patients were significantly increased, but the cortisol levels did not change significantly. During a 6 month follow-up, all behavioral problems assessed using the CBCL improved significantly. Changes in salivary DHEA levels were positively correlated with changes in salivary cortisol levels (r=0.44, p=0.004); however, changes in salivary levels of DHEA, cortisol, and the DHEA/cortisol ratio were not significantly correlated with change in any subscales of the CBCL. Mean doses of MPH were not significantly correlated with changes in neurosteroid levels and behavioral symptoms.

CONCLUSIONS

These findings provide evidence that MPH administration might affect DHEA levels and DHEA/cortisol ratios. Whether levels of neurosteroids are directly associated with brain function or behavioral problems in ADHD patients warrants further investigation.

Pharmacokinetic and pharmacodynamic effects of methylphenidate and MDMA administered alone or in combination

Methylphenidate and 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') are widely misused psychoactive drugs. Methylphenidate increases brain dopamine and norepinephrine levels by blocking the presynaptic reuptake transporters. MDMA releases serotonin, dopamine and norepinephrine through the same transporters. Pharmacodynamic interactions of methylphenidate and MDMA are likely. This study compared the pharmacodynamic and pharmacokinetic effects of methylphenidate and MDMA administered alone or in combination in healthy subjects using a double-blind, placebo-controlled, crossover design. Methylphenidate did not enhance the psychotropic effects of MDMA, although it produced psychostimulant effects on its own. The haemodynamic and adverse effects of co-administration of methylphenidate and MDMA were significantly higher compared with MDMA or methylphenidate alone. Methylphenidate did not change the pharmacokinetics of MDMA and vice versa. Methylphenidate and MDMA shared some subjective amphetamine-type effects; however, 125 mg of MDMA increased positive mood more than 60 mg of methylphenidate, and methylphenidate enhanced activity and concentration more than MDMA. Methylphenidate and MDMA differentially altered facial emotion recognition. Methylphenidate enhanced the recognition of sad and fearful faces, whereas MDMA reduced the recognition of negative emotions. Additionally, the present study found acute pharmacodynamic tolerance to MDMA but not methylphenidate. In conclusion, the combined use of methylphenidate and MDMA does not produce more psychoactive effects compared with either drug alone, but potentially enhances cardiovascular and adverse effects. The findings may be of clinical importance for assessing the risks of combined psychostimulant misuse. Trial registration identification number: NCT01465685 (http://clinicaltrials.gov/ct2/show/NCT01465685).

Hypothalamic-pituitary-adrenocortical axis function in attention-deficit hyperactivity disorder

The hypothalamic-pituitary-adrenocortical axis plays a critical role in mediating the physiological response to the imposition of stress. There are theoretical reasons to expect reduced basal cortisol secretion and cortisol hyporeactivity in hyperactive/impulsive or combined type attention-deficit hyperactivity disorder (ADHD). Early studies reported profound abnormalities in the diurnal rhythm of cortisol secretion or the cortisol response to stress in children with severe or persistent ADHD. However, subsequent work using larger samples or improved methods has not provided convincing evidence for changes in basal cortisol secretion in non-comorbid forms of ADHD. In contrast, children with ADHD and comorbid oppositional defiant disorder show lower basal cortisol concentrations and a blunted cortisol awakening response. With respect to cortisol reactivity to stress in ADHD, recent evidence has been mixed, with some studies reporting normal cortisol responses and others showing blunted cortisol responses in non-comorbid ADHD. Again, it appears important to consider whether comorbid disorders are present, because children with ADHD and comorbid disruptive behavior disorders exhibit blunted cortisol responses, whereas those with comorbid anxiety disorders show enhanced cortisol responses to stress. Longitudinal studies are required to investigate whether abnormalities in cortisol secretion play a causal role in the etiology of ADHD and related disruptive behavior disorders.

Association of salivary dehydroepiandrosterone levels and symptoms in patients with attention deficit hyperactivity disorder during six months of treatment with methylphenidate

This prospective study aimed to determine whether salivary levels of dehydroepiandrosterone (DHEA) in patients with attention deficit hyperactivity disorder (ADHD) change significantly during 6 months of treatment with methylphenidate (MPH), and to investigate long-term relationship between these levels and ADHD symptoms. Fifty ADHD patients aged between 6 and 12 years, and 50 age- and gender-matched healthy subjects were recruited. ADHD patients were prescribed oral MPH with a dose range of 5-15 mg/day at the discretion of the psychiatrist. DHEA levels were determined from saliva samples collected from both ADHD patients and healthy subjects at pretreatment and 1, 3, and 6 months from pretreatment visit. ADHD symptoms were evaluated with the Swanson, Nolan, and Pelham, Version IV Scale for ADHD and the ADHD Rating Scale, and computerized Continuous Performance Test (CPT). The results showed that salivary DHEA levels significantly increased in ADHD patients during the 6-month course of methylphenidate treatment, but the DHEA levels did not significantly change in the untreated healthy group during the 6-month period of natural observation. For the longitudinal observation, among ADHD patients, the salivary DHEA levels were independently correlated with distraction and impulsivity performance in the CPT, but not correlated with inattention and hyperactivity in the clinical ADHD symptoms. Whether DHEA exerts effects on neurocognitive functions as mediators or independently of MPH warrants further investigation.

Venous plasma nicotine correlates of hormonal effects of tobacco smoking

The present study resolves some of the discrepancies in the literature by correlating the effects of tobacco smoking on hormone release with venous plasma nicotine levels. Cortisol, prolactin, and beta-endorphin concentrations were measured. Habitual male tobacco users smoked denicotinized (very low nicotine) and average nicotine cigarettes in the morning after overnight tobacco abstinence. Several venous blood samples were withdrawn before and during the smoking sessions for subsequent analyses. The increases in plasma nicotine correlated well with plasma cortisol and prolactin levels (correlation coefficients r=0.66 and 0.53, respectively, p<0.05). This study quantifies the well known increase in plasma cortisol and prolactin after nicotine postsmoking for about 1h with peak plasma levels up to 35 ng/ml. Contrary to most abused drugs which release dopamine and decrease prolactin, nicotine concentration correlated with increased prolactin release. Increases in maximal plasma beta-endorphin levels following tobacco smoking were barely statistically significant with insufficient data to obtain a correlation coefficient.

Cocaine responsiveness or anhedonia in rats treated with methylphenidate during adolescence

Methylphenidate (MPH) treatment in boys diagnosed with ADHD is reported to decrease the risk of drug abuse in adulthood. Similarly, MPH treatment appears to decrease the cocaine preference of male rats during conditioned place preference (CPP) tests. However, the effects of MPH treatment on later drug use of girls/women or CPP in female rodents have not been fully examined, nor have a clinically-relevant MPH dose and/or administration route been thoroughly studied. Here, Sprague-Dawley rats (n=34/sex/treatment) were treated orally 3x/day on postnatal days (PNDs) 29-50 with water or 3mg MPH/kg, a dose producing serum levels within the human clinical range. CPP assessments to cocaine (10 mg/kg, ip) (PNDs 62-71) indicated MPH-treated rats were less active during pre- and postconditioning sessions (p<.04), but there were no significant MPH-related differences in conditioning strength. Baseline open field activity at PND 84 indicated that MPH-treated females were more active than same-sex controls (p<.05). A cocaine challenge (10 mg/kg, ip) elevated activity similarly in MPH-treated and controls of both sexes. As an anhedonia measure, saccharin solution intake on PNDs 87-90 indicated no significant MPH effects. Estrous cycle phase did not appear to affect cocaine response during CPP or open field assessments. Hormonal levels at PND 90 indicated 63% higher corticosterone levels in MPH-treated females relative to same-sex controls (p<.05), a finding that deserves further investigation. These results address some of the major issues surrounding animal models of MPH treatment and provide additional support for a lack of severe long-term behavioral effects of adolescent MPH.

Hiperatividade e déficit de atenção: o tratamento prejudica o crescimento estatural?

O presente estudo avaliou a influência de drogas estimulantes usadas no déficit de atenção e hiperatividade no crescimento estatural. Os autores procederam a uma revisão de literatura coletando artigos publicados sobre déficit de atenção e hiperatividade e sua relação com a baixa estatura. A fonte consultada foi o PubMed e o tópico levantado foi "Crescimento e Metilfenidato"/"Déficit de atenção e hiperatividade versus baixa estatura"/"Metilfenidato e distúrbios de crescimento". Os transtornos de atenção e hiperatividade constituem-se em situações clínicas difíceis, por interferir no bem-estar da criança e no seu relacionamento social, com prejuízos de seu desenvolvimento escolar. Uma vez feito o diagnóstico, as medicações estimulantes como o metilfenidato têm papel primordial no tratamento, mas muito se teme com relação a certos efeitos colaterais, particularmente a perda de peso e a perda estatural. Revisou-se uma série de publicações a respeito e pôde-se verificar que não há consenso sobre tais efeitos colaterais, mas que, mesmo quando ocorrem, não são suficientemente intensos para impedir o tratamento. Um julgamento da relação custo-benefício da medicação é sempre apropriado, mas os benefícios obtidos com a medicação e com a melhora do rendimento escolar e das relações sociais da criança não devem ser esquecidos. Uma cuidadosa monitorização da curva pondoestatural permite que o médico vigie com segurança o tratamento prescrito e possa tomar decisões se julgar que o prejuízo estatural compromete o bem-estar do paciente.

Effect of stimulants on height and weight: a review of the literature

OBJECTIVE

Stimulant medications are effective treatments for attention-deficit/hyperactivity disorder, but concerns remain about their effects on growth.

METHOD

We provide a quantitative analysis of longitudinal studies about deficits in expected growth among children with attention-deficit/hyperactivity disorder treated with stimulant medication. Study selection criteria were use of DSM criteria or clear operational definitions for hyperactivity or minimal brain dysfunction; outcome measures including raw, standardized, or percentile measurement of change in height and/or weight; first assessment of effects on growth occurred during childhood; and follow-up for at least 1 year. For issues not suitable for quantitative analyses, we provide a systematic, qualitative review.

RESULTS

The quantitative analyses showed that treatment with stimulant medication led to statistically significant delays in height and weight. This review found statistically significant evidence of attenuation of these deficits over time. The qualitative review suggested that growth deficits may be dose dependent, deficits may not differ between methylphenidate and amphetamine, treatment cessation may lead to normalization of growth, and further research should assess the idea that attention-deficit/hyperactivity disorder itself may be associated with dysregulated growth.

CONCLUSIONS

Treatment with stimulants in childhood modestly reduced expected height and weight. Although these effects attenuate over time and some data suggest that ultimate adult growth parameters are not affected, more work is needed to clarify the effects of continuous treatment from childhood to adulthood. Although physicians should monitor height, deficits in height and weight do not appear to be a clinical concern for most children treated with stimulants.

The stress response in adolescents with inattentive type ADHD symptoms

OBJECTIVE

To investigate the hypothalamic pituitary adrenal (HPA) axis response to a stressor in adolescents with inattentive type attention-deficit hyperactivity disorder symptoms (ADHD-I).

METHOD

Salivary cortisol was measured in threshold inattentive (TI, n = 7), moderately inattentive (MI, n = 13) and no symptom (comparison) (n = 19) groups of healthy, young adolescents, based on symptom counts, prior to and after an induced social/cognitive stressor.

RESULTS

The TI group displayed a significant decrease in cortisol post stressor whereas both the MI and comparison groups showed an increase in cortisol.

CONCLUSION

The diagnostic threshold of inattentive type ADHD shows HPA axis dysregulation whereas the more mild form does not show dysfunction.

The diurnal cortisol cycle in delinquent male adolescents and normal controls

Patterns of low hypothalamus-pituitary-adrenal (HPA) activity have been observed in antisocial groups. As conflicting results have been reported in children and adolescents, the aim of this study was to further investigate HPA activity in antisocial behavior by studying the relationship between the diurnal cortisol cycle, as well as the cortisol awakening response (CAR), and antisocial behavior in male adolescents. The diurnal cortisol cycle and the CAR during the first hour after awakening were compared between 12- to 14-year-old boys who attended a delinquency diversion program (DP), with and without a disruptive behavior disorder (DBD) (respectively DP+; n=24 and DP-; n=65), and matched normal controls (NC; n=32). The DP+ group, but not the DP- group, showed a significantly slower decrease of cortisol during the diurnal cycle than the NC group. Furthermore, the DP+ group had significantly lower cortisol levels in the first hour after awakening as compared with the NC group. The results indicate altered HPA activity in delinquent boys with a DBD. Etiological mechanisms, directions for future research, and clinical implications are discussed.

Salivary cortisol levels and dental anxiety in children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is a common developmental disorder. The present study tested the hypotheses that children with ADHD, particularly those exhibiting severe hyperactivity and impulsivity, have a different stress reaction (measured by salivary cortisol) during a dental recall visit and are more dentally anxious than children in a control group. Eighteen children with ADHD and a control group of 71 children, all 13 yr of age, underwent a clinical dental examination and completed the Corah Dental Anxiety Scale (CDAS). Four saliva samples were gathered for analysis of cortisol: one prior to dental examination, one after, and two the following morning. The subgroup ADHD with hyperactivity/impulsivity had statistically significantly lower cortisol levels than the control group 30 min after awakening. When cortisol values were plotted on a timeline, this subgroup always had lower cortisol concentrations than children in the control group. There was a significant correlation between CDAS scores and cortisol concentrations prior to the dental examination in both the ADHD and the control group. Behavioral expressions of anxiety in children with ADHD may be different from those in other children, not only due to the characteristics of their disorder, but also because of lower stress reactivity.

The effect of long-term antipsychotic treatment on prolactin

OBJECTIVE

This naturalistic, cross-sectional study was designed to assess the risk of prolactin level elevation and associated side effects in youths taking long-term atypical antipsychotic medication.

METHOD

Subjects were enrolled from outpatient child psychiatric treatment settings in upstate New York who were taking risperidone, olanzapine, or quetiapine for at least 6 months. Demographic data, medication history, and side effects were elicited at the initial interview. Two fasting morning serum prolactin levels were obtained 1 month apart, and the results were averaged.

RESULTS

Fifty outpatient youths, with a median age of 13 years, were enrolled in the study. The median overall duration of use of an atypical antipsychotic was 22.1 months. The median dose of medication for risperidone was 1.5 mg/day, for olanzapine 10 mg/day, and for quetiapine 200 mg/day. The mean prolactin level among all patients on risperidone was significantly greater than controls, as well as for those on quetiapine or olanzapine.

CONCLUSIONS

The risk of hyperprolactinemia with long-term use of risperidone appears to be significantly greater than for olanzapine or quetiapine. Overt side effects were infrequent in the overall sample, but serum prolactin assessment is recommended for youths taking risperidone chronically. Because of variability found in sequential prolactin samples, repeat samples may be warranted.

Cortisol and treatment effect in children with disruptive behavior disorders: a preliminary study

OBJECTIVE

Basal cortisol and cortisol stress responsivity are valuable biological characteristics of children with disruptive behavior disorder (DBD). In this study, the predictive value of cortisol to outcome of intervention was investigated.

METHOD

Basal cortisol levels and cortisol levels under stress were studied in 22 children with DBD before the start of a psychotherapeutic treatment. The disruptive behavior of the child was assessed before treatment and after cessation (9 months later).

RESULTS

Children with DBD with relatively high and low basal cortisol levels differed in the severity of problem behavior at pretreatment, with the low basal cortisol group having more severe problems. During stress, children with DBD showed either increasing or decreasing cortisol values. Although these cortisol responsivity groups were similar in the severity of behavioral problems at pretreatment, the behavioral problems of the group with high cortisol stress responsivity were significantly lower after the intervention than the behavioral problems of the group with low cortisol stress responsivity.

CONCLUSIONS

In children with DBD, the basal cortisol level was related to the severity of behavioral problems at pretreatment but not to the severity of behavioral problems after treatment. The cortisol response pattern during stress was related to treatment outcome.

Stress responsivity in children with externalizing behavior disorders

Patterns of lower autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis activity have been found in children with oppositional defiant disorder (ODD). The aim of the present study was to investigate whether children with attention-deficit/hyperactivity disorder (ADHD) differ from ODD children with (OD/AD) or without comorbid ADHD in ANS and HPA axis activity under baseline and stressful conditions. The effects of stress on cortisol, heart rate (HR), and skin conductance level (SCL) were studied in 95 children (26 normal control [NC] children and 69 child psychiatric patients referred for externalizing behavior problems [15 ODD, 31 OD/AD, and 23 ADHD]). No baseline differences were found in cortisol between the four groups. However, the ODD and OD/AD groups showed a significantly weaker cortisol response to stress compared to the ADHD and NC groups; the ADHD group had a similar cortisol response as the NC group. Within the ODD group this pattern of low cortisol responsivity was most clearly present in the more severely affected inpatients. With respect to HR, the ODD group had a significantly lower HR during baseline and stressful conditions. The higher HR levels in the OD/AD and ADHD groups were likely to be caused by methylphenidate. The externalizing groups had significantly lower SCL levels, and no differences were found between these groups. It was concluded that differences in cortisol responsivity during stress exposure are important in distinguishing within a group of children with externalizing behavior between those with ODD and ADHD.

Marker gene polymorphisms in hyperkinetic disorder--predictors of clinical response to treatment with methylphenidate?

Gene polymorphisms of the dopamine D4 receptor (DRD4) and serotonin transporter (5-HTT) are under discussion as potential genetic risk factors for hyperkinetic disorder (HD). In this disorder, treatment with the psychostimulant methylphenidate (MPH; Ritalin) induces calming effects and amelioration in only 70% of the patients. MPH blocks the reuptake of dopamine, thus enhancing synaptic dopamine which in turn antagonizes the release of prolactin (PL). Genotyping HD patients for DRD4 and 5-HTT polymorphisms and measuring PL concentrations, we report on an association between the combination DRD4*7/5HTT LL genotype and a reduced improvement in general functioning accompanied by different PL levels upon MPH treatment. Thus, our study supports the hypothesis that marker gene polymorphism may be helpful in identifying MPH non-responders.

Increased adrenal androgen functioning in children with oppositional defiant disorder: a comparison with psychiatric and normal controls

OBJECTIVE

To examine the relationship between adrenal androgens and aggression in children with oppositional and antisocial behavior and to compare their levels with those of psychiatric and normal controls.

METHOD

Dehydroepiandrosterone sulfate (DHEAS) was measured in 24 children with oppositional defiant disorder (ODD), 42 psychiatric controls (including 20 children with attention-deficit/hyperactivity disorder [ADHD]), and 30 normal controls. The children's parents filled out the Child Behavior Checklist (CBCL).

RESULTS

Children with ODD had higher DHEAS levels than either the psychiatric control or normal control groups; DHEAS levels of the latter groups did not differ. Moreover, it was possible to classify children as having either ODD or ADHD on the basis of their DHEAS levels, whereas this was not the case on the basis of the CBCL data.

CONCLUSIONS

The results indicate that adrenal androgen functioning is specifically elevated in children with ODD. It is speculated that the mechanism could be a shift in balance of ACTH-beta-endorphin functioning in the hypothalamic-pituitary-adrenal axis due to early stress or genetic factors.

Growth Deficits in Children With Attention Deficit Hyperactivity Disorder

Stimulant-associated growth deficits in children with attention deficit hyperactivity disorder (ADHD) have long been a concern. Height deficits in preadolescence have been reported, but adult heights have been reported to be uncompromised. It is possible that the catch-up growth that occurs is related to ADHD-associated delayed maturation and not to the cessation of stimulant treatment. To date, no consistent neurohormonal pathophysiology to explain stimulant-associated height deficits has been identified nor have the initial associations of height and weight deficits been replicated. Attention deficit hyperactivity disorder is associated with dysregulation of several neurotransmitter systems, especially the catecholamines, that may alter neuroendocrine function and lead to growth delays. The literature on neuroendocrine aspects of growth and treatment in ADHD and on growth in boys with ADHD who are treated with psychotropics is reviewed, and the results of a controlled study in 124 boys with ADHD are presented. Small but significant differences in height were found between children with and without ADHD. However, the height deficits were evident in early, but not late, adolescence and were not related to the use of psychotropic medications. There was no evidence of weight deficits in children with ADHD relative to control subjects and no relationship between measures of malnutrition and short stature was found. These findings suggest that ADHD may be associated with temporary deficits in height gain through midadolescence that may normalize by late adolescence. This effect appears to be mediated by ADHD and not by its treatment.

Medical use of psychostimulants: an overview

This overview addresses the basic chemistry, pharmacology, activity, medical uses, drug interactions and adverse side effects of the psychostimulants.

Pharmacodynamics of pemoline in attention deficit disorder with hyperactivity

The onset, duration, and offset of pemoline action to improve cognitive performance is examined intensively in 25 prepubescent males suffering from attention-deficit disorder with hyperactivity (ADDH). The purpose was to characterize the pharmacodynamics of pemoline in ADDH patients through correlation of plasma pemoline concentration with psychometric measures of memory search efficiency and paired-associates learning, with the physiological effect of pemoline on dopaminergic transmission concurrently measured by analysis of plasma prolactin response. The effect of pemoline on neuroprocessing is apparent within the first 2 hours after administration with an inverse relationship between plasma pemoline and prolactin concentration present at hour one only (r = 0.84; p = 0.005). Pemoline therapy for 3 weeks does not significantly affect area under the curve for pemoline or prolactin nor did the effect on memory search efficiency decrease, suggesting no apparent tolerance.

Growth hormone and prolactin response to methylphenidate in children with attention deficit disorder

Utilizing a double-blind, drug-placebo design, we examined growth hormone (GH) and prolactin (Pro) response to oral administration of methylphenidate (MPH) in 14 boys (ages 7.0-12.4 years) with Attention Deficit Disorder (ADD). Four conditions representing three different MPH doses (0.3 mg/kg O.D., 0.3 mg/kg B.I.D., 0.6 mg/kg O.D.) and Placebo were compared in each subject, each condition lasting for a period of 3 weeks. GH and Pro response were measured both as maximum peak GH (DGH) or nadir of Pro (DPro) as well as area under the curve for the first four hours after MPH administration (AUCGH, AUCPro). Behavioral measures included parent ratings on the Yale Children's Inventory and teacher ratings on the Yale and Conners Behavior Rating Scales and Kagan's Matching Familiar Figures Test (MFFT). Prolactin response as measured by AUCPro was significantly increased after MPH compared to placebo (t = 2.04, p less than 0.05, placebo vs all doses MPH). This difference observed for AUCPro between placebo and MPH was evident as well when we considered the number of times AUCPro declined after MPH as compared to placebo (p = .018, Fisher's exact test). Within-subjects analysis of covariance demonstrated significant correlations between the improvement in reaction time on the MFFT and 1) GH response (AUCGH, r = .58, p less than .001) and 2) prolactin response (AUCPro, r = .40, p less than .05) and between improvement in attention as measured on the Yale BRS and GH response (AUCGH, r = .57, p less than .05). Our findings suggest that measures other than GH and prolactin may be more desirable measures of brain catecholaminergic functioning.

Opioids and the developing organism: a comprehensive bibliography, 1984-1988

A comprehensive bibliography of the literature concerned with opioids and the developing organism for 1984-1988 is presented. Utilized with companion papers (Neurosci. Biobehav. Rev. 6:439-479; 1982; 8:387-403; 1984), these articles cover the clinical and laboratory references beginning in 1875. For the years 1984, 1985, 1986, 1987, and 1988, a total of 877 citations were recorded. A series of indexes accompanies the citations in order to make the literature more accessible. These indexes are divided into clinical and laboratory topics, and subdivided into such topics as the type of opioid explored and the general area of biological interest (e.g., physiology).