Methamphetamine: Mechanism of Action and Chinese Herbal Medicine Treatment for Its Addiction.

With the proliferation of synthetic drugs, research on the mechanism of action of addictive drugs and treatment methods is of great significance. Among them, methamphetamine (METH) is the most representative amphetamine synthetic drug, and the treatment of METH addiction has become an urgent medical and social problem. In recent years, the therapeutic effects of Chinese herbal medicines on METH addiction have gained widespread attention because of their non-addictiveness, multiple targets, low side effects, low cost, and other characteristics. Previous studies have identified a variety of Chinese herbal medicines with effects on METH addiction. Based on the research on METH in recent years, this article summarizes the mechanism of action of METH as the starting point and briefly reviews the Chinese herbal medicine-based treatment of METH.

Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a major problem in children and adolescents, characterised by age-inappropriate levels of inattention, hyperactivity, and impulsivity, and is associated with long-term social, academic, and mental health problems. The stimulant medications methylphenidate and amphetamine are the most frequently used treatments for ADHD, but these are not always effective and can be associated with side effects. Clinical and biochemical evidence suggests that deficiencies of polyunsaturated fatty acids (PUFA) could be related to ADHD. Research has shown that children and adolescents with ADHD have significantly lower plasma and blood concentrations of PUFA and, in particular, lower levels of omega-3 PUFA. These findings suggest that PUFA supplementation may reduce the attention and behaviour problems associated with ADHD. This review is an update of a previously published Cochrane Review. Overall, there was little evidence that PUFA supplementation improved symptoms of ADHD in children and adolescents. OBJECTIVES: To compare the efficacy of PUFA to other forms of treatment or placebo in treating the symptoms of ADHD in children and adolescents. SEARCH METHODS: We searched 13 databases and two trials registers up to October 2021. We also checked the reference lists of relevant studies and reviews for additional references. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials that compared PUFA with placebo or PUFA plus alternative therapy (medication, behavioural therapy, or psychotherapy) with the same alternative therapy alone in children and adolescents (aged 18 years and under) diagnosed with ADHD. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcome was severity or improvement of ADHD symptoms. Our secondary outcomes were severity or incidence of behavioural problems; quality of life; severity or incidence of depressive symptoms; severity or incidence of anxiety symptoms; side effects; loss to follow-up; and cost. We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We included 37 trials with more than 2374 participants, of which 24 trials were new to this update. Five trials (seven reports) used a cross-over design, while the remaining 32 trials (52 reports) used a parallel design. Seven trials were conducted in Iran, four each in the USA and Israel, and two each in Australia, Canada, New Zealand, Sweden, and the UK. Single studies were conducted in Brazil, France, Germany, India, Italy, Japan, Mexico, the Netherlands, Singapore, Spain, Sri Lanka, and Taiwan. Of the 36 trials that compared a PUFA to placebo, 19 used an omega-3 PUFA, six used a combined omega-3/omega-6 supplement, and two used an omega-6 PUFA. The nine remaining trials were included in the comparison of PUFA to placebo, but also had the same co-intervention in the PUFA and placebo groups. Of these, four trials compared a combination of omega-3 PUFA plus methylphenidate to methylphenidate. One trial each compared omega-3 PUFA plus atomoxetine to atomoxetine; omega-3 PUFA plus physical training to physical training; and an omega-3 or omega-6 supplement plus methylphenidate to methylphenidate; and two trials compared omega-3 PUFA plus dietary supplement to dietary supplement. Supplements were given for a period of between two weeks and six months. Although we found low-certainty evidence that PUFA compared to placebo may improve ADHD symptoms in the medium term (risk ratio (RR) 1.95, 95% confidence interval (CI) 1.47 to 2.60; 3 studies, 191 participants), there was high-certainty evidence that PUFA had no effect on parent-rated total ADHD symptoms compared to placebo in the medium term (standardised mean difference (SMD) -0.08, 95% CI -0.24 to 0.07; 16 studies, 1166 participants). There was also high-certainty evidence that parent-rated inattention (medium-term: SMD -0.01, 95% CI -0.20 to 0.17; 12 studies, 960 participants) and hyperactivity/impulsivity (medium-term: SMD 0.09, 95% CI -0.04 to 0.23; 10 studies, 869 participants) scores were no different compared to placebo. There was moderate-certainty evidence that overall side effects likely did not differ between PUFA and placebo groups (RR 1.02, 95% CI 0.69 to 1.52; 8 studies, 591 participants). There was also moderate-certainty evidence that medium-term loss to follow-up was likely similar between groups (RR 1.03, 95% CI 0.77 to 1.37; 13 studies, 1121 participants). AUTHORS' CONCLUSIONS: Although we found low-certainty evidence that children and adolescents receiving PUFA may be more likely to improve compared to those receiving placebo, there was high-certainty evidence that PUFA had no effect on total parent-rated ADHD symptoms. There was also high-certainty evidence that inattention and hyperactivity/impulsivity did not differ between PUFA and placebo groups. We found moderate-certainty evidence that overall side effects likely did not differ between PUFA and placebo groups. There was also moderate-certainty evidence that follow-up was similar between groups. It is important that future research addresses the current weaknesses in this area, which include small sample sizes, variability of selection criteria, variability of the type and dosage of supplementation, and short follow-up times.

Methamphetamine: Mechanism of Action and Chinese Herbal Medicine Treatment for Its Addiction / 中国结合医学杂志

With the proliferation of synthetic drugs, research on the mechanism of action of addictive drugs and treatment methods is of great significance. Among them, methamphetamine (METH) is the most representative amphetamine synthetic drug, and the treatment of METH addiction has become an urgent medical and social problem. In recent years, the therapeutic effects of Chinese herbal medicines on METH addiction have gained widespread attention because of their non-addictiveness, multiple targets, low side effects, low cost, and other characteristics. Previous studies have identified a variety of Chinese herbal medicines with effects on METH addiction. Based on the research on METH in recent years, this article summarizes the mechanism of action of METH as the starting point and briefly reviews the Chinese herbal medicine-based treatment of METH.

Behavioral Battery for Testing Candidate Analgesics in Mice. I. Validation with Positive and Negative Controls.

This study evaluated a battery of pain-stimulated, pain-depressed, and pain-independent behaviors for preclinical pharmacological assessment of candidate analgesics in mice. Intraperitoneal injection of dilute lactic acid (IP acid) served as an acute visceral noxious stimulus to produce four pain-related behaviors in male and female ICR mice: stimulation of 1) stretching, 2) facial grimace, 3) depression of rearing, and 4) depression of nesting. Additionally, nesting and locomotion in the absence of the noxious stimulus were used to assess pain-independent drug effects. These six behaviors were used to compare effects of two mechanistically distinct but clinically effective positive controls (ketoprofen and oxycodone) and two negative controls that are not clinically approved as analgesics but produce either general motor depression (diazepam) or motor stimulation (amphetamine). We predicted that analgesics would alleviate all IP acid effects at doses that did not alter pain-independent behaviors, whereas negative controls would not. Consistent with this prediction, ketoprofen (0.1-32 mg/kg) produced the expected analgesic profile, whereas oxycodone (0.32-3.2 mg/kg) alleviated all IP acid effects except depression of rearing at doses lower than those that altered pain-independent behaviors. For the negative controls, diazepam (1-10 mg/kg) failed to block IP acid-induced depression of either rearing or nesting and only decreased IP acid-stimulated behaviors at doses that also decreased pain-independent behaviors. Amphetamine (0.32-3.2 mg/kg) alleviated all IP acid effects but only at doses that also stimulated locomotion. These results support utility of this model as a framework to evaluate candidate-analgesic effects in a battery of complementary pain-stimulated, pain-depressed, and pain-independent behavioral endpoints. SIGNIFICANCE STATEMENT: Preclinical assays of pain and analgesia often yield false-positive effects with candidate analgesics. This study used two positive-control analgesics (ketoprofen, oxycodone) and two active negative controls (diazepam, amphetamine) to validate a strategy for distinguishing analgesics from nonanalgesics by profiling drug effects in a battery of complementary pain-stimulated, pain-depressed, and pain-independent behaviors in male and female mice.

A Case of Narcolepsy Type 2 and Postural Tachycardia Syndrome Secondary to Lesions of the Thalamus and Amygdala.

ABSTRACT: Although there are reports of narcolepsy type 1 caused by lesions of the central nervous system, there are far fewer reports of narcolepsy type 2 (NT2) caused by discrete brain lesions. We report a case of a patient in whom NT2 was diagnosed after a viral illness, and inflammatory lesions in the right thalamus and amygdala were found. In addition, symptoms of autonomic impairment developed and postural tachycardia syndrome was subsequently diagnosed in this patient. To our knowledge this is the first reported case of NT2 resulting from central nervous system lesions in these discrete locations, as well as the first reported case of postural tachycardia syndrome associated with narcolepsy.

Effect of traditional medicine brahmi vati and bacoside A-rich fraction of Bacopa monnieri on acute pentylenetetrzole-induced seizures, amphetamine-induced model of schizophrenia, and scopolamine-induced memory loss in laboratory animals.

OBJECTIVE: Brahmi vati (BV) is an Ayurvedic polyherbal formulation used since ancient times and has been prescribed in seizures associated with schizophrenia and related memory loss by Ayurvedic practitioners in India. The aim of the study was to investigate these claims by evaluation of anticonvulsant, antischizophreniac, and memory-enhancing activities. Antioxidant condition of brain was determined by malondialdehyde (MDA) and reduced glutathione (GSH) levels estimations. Acetylcholinesterase (AChE) was quantitatively estimated in the brain tissue. METHODS: Brahmi vati was prepared in-house by strictly following the traditional Ayurvedic formula. Bacoside A rich fraction (BA) of Bacopa monnieri was prepared by extraction and fractionation. It was than standardized by High Performance Liquid Chromatography (HPLC) and given in the dose of 32.5mg/kg body weight to the different groups of animals for 7days. On the seventh day, activities were performed adopting standard procedures. KEY FINDINGS: Brahmi vati showed significant anticonvulsant, memory-enhancing and antischizophrenia activities, when compared with the control groups and BA. It cause significantly higher brain glutathione levels. Acetylcholinesterase activity was found to be significantly low in BV-treated group. CONCLUSION: The finding of the present study suggests that BV may be used to treat seizures associated with schizophrenia and related memory loss.

Bases para la elección del tratamiento farmacológico en el trastorno por déficit de atención/hiperactividad / Bases for the selection of pharmacological treatment in attention deficit hyperactivity disorder

Objetivos. Recoger algunos factores que pueden ayudar al clínico a diseñar un plan de tratamiento farmacológico para el niño y adolescente con trastorno por déficit de atención/hiperactividad (TDAH), y realizar una revisión de la bibliografía sobre factores para la selección del tratamiento farmacológico en el TDAH. Desarrollo. El tratamiento del TDAH requiere el diseño de un plan completo e individualizado para cada paciente, familia y entorno, que incluye tres partes principales: psicoeducación y entrenamiento en manejo conductual, apoyo académico y medicación. Los estimulantes (metilfenidato) y los no estimulantes (atomoxetina) son los dos fármacos aprobados en España para niños y adolescentes y para continuación del tratamiento en adultos con TDAH. El tamaño del efecto de los estimulantes (1,0) es mayor que el de la atomoxetina (0,7-0,8). La metodología del estudio, especialmente la duración, puede afectar el tamaño del efecto. El rango del número de pacientes necesario para tratar es de 1,9 a 5,3, superior al de otros fármacos para otros trastornos (antidepresivos o antipsicóticos). Entre los factores que condicionan la elección del tratamiento farmacológico del TDAH están: comorbilidad, efectos adversos potenciales (especialmente bajo apetito, insomnio,tics y potencial de abuso de la medicación), preferencia de los padres y del paciente, necesidad de acción a lo largo del día o en momentos concretos del día, necesidad de inicio rápido de acción, precio y necesidad de visado de la medicación. Conclusiones. Existen unos factores asociados al propio paciente y a las características del TDAH, al fármaco y al entorno o situación del paciente que deben considerarse al seleccionar una medicación para el TDAH (AU)

Aims. To collect some factors that can help the clinician to design a plan of pharmacologic treatment for children and adolescents with attention deficit hyperactivity disorder (ADHD). Development. We did a literature search of current available studies on the pharmacological treatment of ADHD. Treatment of ADHD requires the design of a comprehensive and individualized plan for each patient, family and environment, which includes three main parts: psychoeducation and behavioral management training, academic support, and medication. Stimulants (methylphenidate) and non-stimulants (atomoxetine) are the two drugs approved in Spain for children and adolescents and then treatment in adults with ADHD. The effect size of stimulants (1.0) is higher than for atomoxetine (0.7-0.8). The methodology of the study, especially the duration, may affect the effect size. The range of NNT is 1.9 to 5.3, higher than other drugs for other disorders (antidepressants or antipsychotics). Some factors that impact the choice of medication for ADHD are: comorbidity, potential adverse effects (especially low appetite, insomnia, tics and potential abuse of medication), parental preference and patient need for action along the day or at specific times of day, need rapid onset of action, and any visa price of medication. Conclusions. There are some factors related to the patient and the features of ADHD, drug, and the patient’s situation or environment which should be considered when selecting a treatment for ADHD (AU)

Pathogenic disruption of DISC1-serine racemase binding elicits schizophrenia-like behavior via D-serine depletion.

Perturbation of Disrupted-In-Schizophrenia-1 (DISC1) and D-serine/NMDA receptor hypofunction have both been implicated in the pathophysiology of schizophrenia and other psychiatric disorders. In the present study, we demonstrate that these two pathways intersect with behavioral consequences. DISC1 binds to and stabilizes serine racemase (SR), the enzyme that generates D-serine, an endogenous co-agonist of the NMDA receptor. Mutant DISC1 fails to bind to SR, facilitating ubiquitination and degradation of SR and a decrease in D-serine production. To elucidate DISC1-SR interactions in vivo, we generated a mouse model of selective and inducible expression of mutant DISC1 in astrocytes, the main source of D-serine in the brain. Expression of mutant DISC1 downregulates endogenous DISC1 and decreases protein but not mRNA levels of SR, resulting in diminished production of D-serine. In contrast, mutant DISC1 does not alter levels of ALDH1L1, connexins, GLT-1 or binding partners of DISC1 and SR, LIS1 or PICK1. Adult male and female mice with lifelong expression of mutant DISC1 exhibit behavioral abnormalities consistent with hypofunction of NMDA neurotransmission. Specifically, mutant mice display greater responses to an NMDA antagonist, MK-801, in open field and pre-pulse inhibition of the acoustic startle tests and are significantly more sensitive to the ameliorative effects of D-serine. These findings support a model wherein mutant DISC1 leads to SR degradation via dominant negative effects, resulting in D-serine deficiency that diminishes NMDA neurotransmission thus linking DISC1 and NMDA pathophysiological mechanisms in mental illness.

Evaluación de la efectividad y seguridad de la anfetamina para déficit atencional en población entre 6 y 19 años: revisión sistemática / Effectiveness and safety of amphetamine for ADHD in population between 6 and 19 years: a systematic review

Introducción: el trastorno por déficit de atención e hiperactividad (TDAH) dispone de tratamiento farmacológico con psicoestimulantes, siendo el metilfenidato es de mayor uso; sin embargo, también se dispone de anfetaminas, de aquí la importancia de conocer tanto su efectividad como su seguridad. Objetivo: identificar, sintetizar y evaluar la mejor evidencia disponible sobre la efectividad y seguridad de la anfetamina en el TDAH en la población de 6 a 19 años. Métodos: se realizó una revisión sistemática de estudios de intervenciones que evaluaron efectividad comparada entre anfetamina y metilfenidato, que se midió en términos de funcionamiento educacional, funcionamiento psicosocial, calidad de vida y efectos adversos. Se usaron las bases de datos hasta febrero de 2012 en inglés y castellano: PubMed, LILACS, Cochrane, DARE y National Guideline Clearinghouse. Los artículos que cumplieron con criterios de inclusión fueron evaluados por dos investigadores en forma independiente. Resultados: de los 114 estudios encontrados inicialmente, se incluyeron 4, entre ellos una revisión sistemática, un artículo primario y 2 guías clínicas. Conclusiones: la evidencia científica disponible sobre la anfetamina para el tratamiento del TDAH la recomienda como alternativa al MPH. Son necesarios más estudios de calidad.

Introduction: Attention deficit hyperactivity disorder (ADHD) drug treatment is based on psychostimulants, and methylphenidate is still the most widely used one. Other psychostimulants used include amphetamines, hence the importance of knowing both its effectiveness and safety. Purpose: To identify, synthesize and evaluate the best available evidence on the effectiveness and safety of amphetamine in ADHD in the 6-19 year-old population. Methods: A systematic review of studies that evaluated the effectiveness of interventions comparing amphetamine to methylphenidate was conducted. The outcomes measured were educational performance, psychosocial functioning, quality of life and adverse effects. The following databases were searched up to February 2012 in English and Spanish: PubMed/MEDLINE, LILACS, Cochrane, DARE and National Guideline Clearinghouse. The articles that met inclusion criteria were assessed by two researchers independently. Results: Of the 114 studies found initially, four were included, among which a systematic review, a primary article and two clinical guidelines. Conclusions: The evidence on amphetamine for ADHD treatment recommends its use as an alternative to MPH. Further good-quality studies are needed.

Spontaneously Hypertensive Rats (SHR) present deficits in prepulse inhibition of startle specifically reverted by clozapine.

Deficits in an operational measure of sensorimotor gating - the prepulse inhibition of startle (PPI) - are presented in psychiatric disorders such as schizophrenia, bipolar disorder, and attention deficit/hyperactivity disorder (ADHD). Some previous studies showed that the spontaneously hypertensive rats (SHR) present PPI deficit. Although SHR is suggested as an animal model to study ADHD, we have suggested that the behavioral phenotype of this strain mimics some aspects of schizophrenia. The aim of this study was to characterize the PPI response in SHR. Pharmacological characterization consisted in the evaluation of the effects of the following drugs administered to adult Wistar rats (WR) and SHR previously to the PPI test: amphetamine (used for ADHD and also a psychotomimetic drug), haloperidol and clozapine (antipsychotic drugs), metoclopramide (dopamine antagonist without antipsychotic properties) and carbamazepine (mood stabilizer). Our results showed that SHR presented reduced PPI. This deficit was similar to that induced by amphetamine in WR. Only the atypical antipsychotic clozapine improved the PPI deficit observed in SHR. These findings reinforce the SHR strain as an animal model to study several aspects of schizophrenia, including the abnormalities in sensorimotor gating associated with this disease.

Impulsiveness, overactivity, and poorer sustained attention improve by chronic treatment with low doses of l-amphetamine in an animal model of Attention-Deficit/Hyperactivity Disorder (ADHD).

BACKGROUND: ADHD is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. Overactivity, impulsiveness, and inattentiveness are presently regarded as the main clinical symptoms. There is no biological marker, but there is considerable evidence to suggest that ADHD behavior is associated with poor dopaminergic and noradrenergic modulation of neuronal circuits that involve the frontal lobes. The best validated animal model of ADHD, the Spontaneously Hypertensive Rat (SHR), shows pronounced overactivity, impulsiveness, and deficient sustained attention. The primary objective of the present research was to investigate behavioral effects of a range of doses of chronic l-amphetamine on ADHD-like symptoms in the SHR. METHODS: The present study tested the behavioral effects of 0.75 and 2.2 mg l-amphetamine base/kg i.p. in male SHRs and their controls, the Wistar Kyoto rat (WKY). ADHD-like behavior was tested with a visual discrimination task measuring overactivity, impulsiveness and inattentiveness. RESULTS: The striking impulsiveness, overactivity, and poorer sustained attention seen during baseline conditions in the SHR were improved by chronic treatment with l-amphetamine. The dose-response curves were, however, different for the different behaviors. Most significantly, the 0.75 mg/kg dose of l-amphetamine improved sustained attention without reducing overactivity and impulsiveness. The 2.2 mg/kg dose improved sustained attention as well as reduced SHR overactivity and impulsiveness. DISCUSSION: The effects of l-amphetamine to reduce the behavioral symptoms of ADHD in the SHR were maintained over the 14 days of daily dosing with no evidence of tolerance developing.

Functional magnetic resonance imaging investigation of the amphetamine sensitization model of schizophrenia in healthy male volunteers.

CONTEXT: Recent work suggests that the amphetamine sensitization model of schizophrenia can safely be induced in healthy volunteers and is associated both with behavioral and dopaminergic hypersensitivity to amphetamine. However, the effects of a sensitization on brain function remain unclear. OBJECTIVE: To assess the impact of a sensitizing dosage regimen of dextroamphetamine on human cortical functioning and cognition. DESIGN: Randomized, double-blind, parallel-groups design using pharmacological functional magnetic resonance imaging. SETTING: The neuroimaging research unit at the Institute of Psychiatry, King's College London, London, England. PARTICIPANTS: Healthy male volunteers (n = 22). INTERVENTIONS: Dextroamphetamine (20 mg) or placebo administration at 4 testing sessions, using a dosage regimen shown to induce sensitization (ie, 3 doses administered with a 48-hour interdose interval and a final dose after a 2-week washout period). MAIN OUTCOME MEASURES: Sensitization was characterized by enhanced subjective response to the drug, changes in behavioral performance (reaction time and accuracy), and functional magnetic resonance imaging measurements of brain activity during an N-back working memory task. RESULTS: Sensitization was associated with more rapid responding during the performance of an intermediate-load working memory challenge. During a high-load cognitive challenge, sensitization did not produce performance deficits, but functional magnetic resonance imaging showed hyperactivity of the dorsolateral prefrontal cortex and aberrant recruitment of the superior temporal gyrus, caudate nucleus, and thalamus. Furthermore, the change in striatal activity was negatively correlated with the enhanced subjective effects of the drug, whereas prefrontal hyperactivity was positively correlated with sensitized measures of alertness. CONCLUSIONS: These transient load-dependent abnormalities of frontal and temporal activity induced by amphetamine sensitization support neuroimaging findings in schizophrenic patients, implying that amphetamine sensitization may help to bridge pathophysiological theories of schizophrenia that focus on pharmacological (dopaminergic) and cognitive mechanisms, respectively.

Attention-deficit-hyperactivity disorder: an update.

Attention-deficit-hyperactivity disorder (ADHD) is a common neuropsychiatric disorder that impairs social, academic, and occupational functioning in children, adolescents, and adults. In patients with ADHD, neurobiologic research has shown a lack of connectivity in key brain regions, inhibitory control deficits, delayed brain maturation, and noradrenergic and dopaminergic dysfunction in multiple brain regions. The prevalence of this disorder in the United States is 6-9% in youth (i.e., children and adolescents) and 3-5% in adults. Prevalence rates for youth are similar worldwide. Children with ADHD are at greater risk than children without ADHD for substance abuse and delinquency whether or not they receive drug therapy; however, early treatment with psychoeducation as well as drug therapy and/or behavioral intervention may decrease negative outcomes of ADHD, including the rate of conduct disorder and adult antisocial personality disorder. Drug therapy is effective for all age groups, even preschoolers, and for late-onset ADHD in adults. Stimulants, such as methylphenidate and amphetamine, are the most effective therapy and have a good safety profile; although recent concerns of sudden unexplained death, psychiatric adverse effects, and growth effects have prompted the introduction of other therapies. Atomoxetine, a nonstimulant, has no abuse potential, causes less insomnia than stimulants, and poses minimal risk of growth effects. Other drug options include clonidine and guanfacine, but both can cause bradycardia and sedation. Polyunsaturated fatty acids (fish oil), acetyl-L-carnitine, and iron supplements (for youth with low ferritin levels) show promise in improving ADHD symptoms. As long-term studies show that at least 50% of youth are nonadherent with their drug therapy as prescribed over a 1-year period, long-acting formulations (administered once/day) may improve adherence. Comorbid conditions are common in patients with ADHD, but this patient population can be treated effectively with individualized treatment regimens of stimulants, atomoxetine, or bupropion, along with close monitoring.

ADHD, substance use disorders, and psychostimulant treatment: current literature and treatment guidelines.

OBJECTIVE: This review explores the relationship between ADHD and substance use disorder (SUD), factors that determine the abuse potential of psychostimulants, and strategies for identifying and treating at-risk ADHD patients. METHOD: This study uses a Medline review of literature. RESULTS: Psychostimulants, such as methylphenidate and amphetamines, are effective first-line pharmacotherapy for ADHD and when used appropriately in individuals with ADHD do not appear to be frequently abused by patients. Diversion and misuse of prescription stimulants are growing concerns, especially among young adults and college students. Short-acting psychostimulant formulations may have higher potential for abuse, misuse, and diversion, but more data are needed to substantiate this observation. Nonstimulant treatments for ADHD may be considered for patients at particularly high risk for substance use, misuse, or diversion of stimulants. CONCLUSION: In treating patients with ADHD and comorbid substance use, psychostimulants may be a useful pharmacologic alternative. However, the risks of such treatment with high-risk populations must be considered alongside potential benefits.

Axonal plasticity is associated with motor recovery following amphetamine treatment combined with rehabilitation after brain injury in the adult rat.

Clinical and laboratory studies have suggested that amphetamine treatment when paired with rehabilitation results in improved recovery of function after stroke or traumatic brain injury. In the present study, we investigated whether new anatomical pathways developed in association with improved motor function after brain damage and amphetamine treatment linked with rehabilitation. Following a unilateral sensorimotor cortex lesion in the adult rat, amphetamine (2 mg/kg) was administered in conjunction with physiotherapy sessions on postoperative days two and five. Physiotherapy was continued twice daily for the first 3 weeks after injury, and then once daily until week six. Performance on skilled forelimb reaching and ladder rung walking was used to assess motor improvement. Our results show that animals with sensorimotor cortical lesions receiving amphetamine treatment linked with rehabilitation had significant improvement in both tasks. Neuroanatomical tracing of efferent pathways from the opposite, non-damaged cortex resulted in the novel finding that amphetamine treatment linked with rehabilitation, significantly increased axonal growth in the deafferented basilar pontine nuclei. These results support the notion that pharmacological interventions paired with rehabilitation can enhance neuronal plasticity and thereby improve functional recovery after CNS injury.

Algorithmically designed peptides ameliorate behavioral defects in animal model of ADHD by an allosteric mechanism.

This study exemplifies the use of three ADHD-relevant methodological innovations. (1) The use of novel, patented, computational peptide design techniques to generate peptides targeting the extra-cellular and para-transmembrane amino acid loops of the putatively ADHD-involved, D(2) dopamine receptor, D(2)DAR; (2) experimental evidence that these peptides in L-amino acid/ortho ordered or D-amino acid/reverse ordered (retro-inverso), D(2)DAR, hydrophobic eigenmode matched forms, evoked positive allosteric and indirect agonist influences on in vitro stably receptor transfected CHO and LtK cells and on in vivo, brain mediated activity; (3) a representative 15 residue all-D-amino acid, D(2) mode matched peptide, given parenterally, was found to "repair" a key aberrant ADHD behavioral characteristic in a standard animal model of ADHD, the Spontaneously Hypertensive Rat, SHR, relative to its progenitor species control, the Wistar-Kyoto rat, WKY. The representative, retro-inverso peptide, all-D-LLYKNKPRYPKRNRE, reversed SHR's relative deficiency in sensory motor gating (pre-pulse inhibition, PPI) while leaving SHR's nonselective attention (rearings), impulsive behavior (time in center), and activity level (timed total motor behavior) unchanged. Amphetamine also reversed SHRs sensory gating defect, but with significant increases in nonselective attention, impulsivity and hyperactivity. These preliminary results suggest the possibility of a new, "softer" pharmacological approach to ADHD: hydrophobic mode matched peptide allosteric augmentation of the activity of indigenous dopamine with respect to D(2)DAR mediated function, in place of stimulant drug-induced presynaptic dopamine release or impairment of dopamine uptake.

No benefit from D-amphetamine when added to physiotherapy after stroke: a randomized, placebo-controlled study.

OBJECTIVE: To assess the effect of D-amphetamine on the recovery of activities of daily living and motor functions after stroke, DESIGN: Randomized, placebo-controlled study, SETTING: Inpatient rehabilitation centre, SUBJECTS: Twenty-four stroke survivors after a first ischaemic supratentorial stroke within six weeks before study onset, severely to moderately affected, with a Barthel Index (0-100) ranging from 25 to 50, no severe concomitant internal, neurological or psychiatric diseases, and participating in a comprehensive rehabilitation programme of 10-12 weeks, INTERVENTIONS: Ten sessions with 10 mg D-amphetamine (or placebo) every fourth day totalling 100 mg in a time period of 36 days combined with physical therapy according to the neurodevelopmental concept within 60 minutes after drug intake. MAIN OUTCOME MEASURES: Barthel Index (0-100) served as the primary outcome measure and the Rivermead Motor Assessment Score with its three sections (gross function, leg and trunk, and arm) as the secondary outcome measure, assessed at days 0, 20, 36, 90, 180 and 360. RESULTS: The two groups did not differ with respect to clinical data and outcome measures at study onset. All patients improved significantly except for arm function over the intervention period and up to day 90 after study onset. The comparison between groups did not reveal any difference at any time; amphetamine-treated patients did not show any increase in motor function or ADL compared with the control group. CONCLUSIONS: The placebo-controlled study failed to show any effect of D-amphetamine on stroke recovery compared with control. The small number of patients, the timing and content of physical therapy were limiting factors of the present study. Further trials are warranted.

A herbal medicine used in the treatment of addiction mimics the action of amphetamine on in vitro rat striatal dopamine release.

Thunbergia laurifolia Linn. (TH) and Simplocos racemosa Roxb. (SY) are herbal medicines used in the treatment of drug addiction without scientific support for their mechanism of action. The present study investigated the effects of these medicinal plants on dopaminergic neurotransmission in comparison with amphetamine. The effect of crude water extracts (0.1 g/ml) of TH and SY on K(+) (20 mM)-stimulated dopamine release from rat striatal slices were compared with amphetamine (10(-4) M) using high-performance liquid chromatography with electrochemical detection to measure endogenous dopamine. Amphetamine and TH, but not SY, significantly increased K(+)-stimulated dopamine release (P < 0.001) from rat striatal slices when compared with K(+)-stimulated alone. TH potentiated the effect of amphetamine on K(+)-stimulated dopamine release (P < 0.001) when compared with amphetamine alone. The results indicate that TH may stimulate dopamine release in the same manner as amphetamine. It remains to be determined whether the effect of these extracts on dopamine function is important in their therapeutic use in the treatment of drug addiction.

Comparison of analgesic effects of khat (Catha edulis Forsk) extract, D-amphetamine and ibuprofen in mice.

We have compared the analgesic properties of khat (Catha edulis Forsk) extract, amphetamine and ibuprofen in mice. After intragastric administration of the drugs analgesia was measured relative to water-injected controls using the hot-plate, the tail-flick, and abdominal-constriction tests. At the highest doses examined (amphetamine 1.8 mg kg(-1), ibuprofen 90 mg kg(-1), khat extract 1800 mg kg(-1)), all three substances produced analgesia, but the order of efficacy varied with the test. Khat and ibuprofen were significantly different from the control in the hot-plate assay at three or more time points post-injection. In the tail-flick test, khat and amphetamine were efficacious; ibuprofen means were somewhat lower but still significantly different from control. Higher doses of the drugs decreased the number of responses in the acetic acid-induced abdominal-constriction assay. We conclude that khat, like amphetamine and ibuprofen, can relieve pain. Differences in assay results may reflect differences in modes and sites of action, as well as in the type of pain generated by the chemical and thermal stimuli for nociception.

Differential effects of monoaminergic agonists on alcohol intake in rats fed a tryptophan-enhanced diet.

The goal of the present study was to determine if enhancement of tryptophan levels in a nutritionally balanced liquid diet would affect alcohol intake in a two-bottle choice procedure. Furthermore. the monoaminergic agonists amphetamine, phentermine (dopaminergic- and noradrenergic-releasing drugs), and fenfluramine (a serotonin releaser) were administered to determine if these drugs reduced alcohol intake in animals fed the tryptophan-enhanced diet compared to those fed an alcohol-containing diet without added tryptophan. Amphetamine 0.5 and 2 mg/kg and phentermine 4 mg/kg selectively reduced alcohol intake in animals fed the tryptophan-enhanced diet; higher doses also reduced alcohol intake in animals fed the control alcohol diet. Three hours after drug administration, phentermine 2 and 4 mg/kg produced increases in consumption of the nonalcoholic diet in animals fed the control diet without affecting consumption in animals fed the tryptophan-enhanced diet. Finally, animals in the tryptophan-enhanced group gained less weight than those animals fed an identical diet without the added tryptophan. Neurochemical analysis revealed that the tryptophan-fed groups showed increased 5-HIAA concentrations and serotonin turnover in the striatum. hypothalamus, and frontal cortex compared to animals fed the control diet. The tryptophan-alcohol group also showed almost double the tryptophan levels in the hypothalamus compared to the tryptophan-isocaloric group. These results indicate that, whereas increasing tryptophan levels by itself was not sufficient to alter consumption of an alcohol-containing diet, the administration of monoaminergic agonists significantly interacted with tryptophan in a dose-dependent manner to reduce intake of an alcohol-containing diet without reducing intake of an isocaloric diet.