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Biomedical subjects

S R Pliszka

Publications and source records attributed to S R Pliszka.

At least 19 recordsLinked to original sources
PubMed1999

Nontricyclic antidepressants: current trends in children and adolescents.

OBJECTIVES: First, to review the extant data on the safety and efficacy of the use of nontricyclic antidepressants in children and adolescents; second, to identify the main limitations of our current knowledge in this area; and third, to point to future research directions. METHOD: A Medline search and a review of previous scientific meetings were conducted; all available reports on the efficacy and safety of nontricyclic antidepressants in children and adolescents were critically reviewed. RESULTS: As in adults, also in children nontricyclic antidepressants are potentially useful in treating a variety of psychiatric disorders. The data supporting their efficacy, however, are quite limited. Obsessive-compulsive disorder is the only psychiatric diagnosis for which pediatric use of selective serotonin reuptake inhibitors has been approved. One placebo-controlled study in children and adolescents with major depression supports the efficacy of fluoxetine. Other clinical trials of nontricyclic antidepressants in depressed adolescents are in progress. Available data indicate that the safety of these medications is good, at least in the short term. CONCLUSIONS: The potential usefulness of nontricyclic antidepressants for children and adolescents suffering from a range of disorders is considerable. While information from adults can suggest potential areas of possible efficacy in pediatric patients suffering from similar psychopathology, further research is essential to provide the necessary information on the efficacy, safety, and pharmacokinetics of these medications in children and adolescents.

Adolescent↗
PubMed1998

The use of psychostimulants in the pediatric patient.

The psychostimulant drugs have a long history of safe and effective usage in the treatment of ADHD. They remain the drugs of first choice in this condition. Children with ADHD should be aggressively treated with at least two different classes of psychostimulants before moving to nonpsychostimulant agents. As long as side effects are not troublesome, higher dosages may be used to adequately control the ADHD symptoms, and such high dosages do not impair learning. No evidence shows long-term effects of psychostimulants on growth. Effective use of the psychostimulants is essential for any clinician involved in the treatment of children with ADHD.

Adolescent↗
PubMed1998

Comorbidity of attention-deficit/hyperactivity disorder with psychiatric disorder: an overview.

Attention-deficit/hyperactivity disorder (ADHD) has been noted to be comorbid with a variety of psychiatric disorders. These include oppositional defiant and conduct disorders, as well as affective, anxiety, and learning disorders. Considerable debate has revolved as to the meaning of this overlap. Does it occur by chance or is it an artifact of referral bias? Are the comorbid conditions secondary to the ADHD, or can other psychiatric disorders masquerade as attentional problems? Alternatively, ADHD may exist as distinct subtypes, each with its specific comorbidity. Studies that have examined the comorbidity of oppositional, conduct, affective, anxiety, and learning disorders in ADHD are reviewed. ADHD and ADHD with conduct disorder appear to be distinct subtypes, possibly with different etiologies. While the short-term response to stimulants is the same in these two groups, children with ADHD and conduct disorder children have higher rates of antisocial personality as adults. Coexisting anxiety appears to attenuate impulsivity in ADHD, and stimulant response is poorer in ADHD children with comorbid anxiety. Anxiety and ADHD appear to be inherited independently. A subset of ADHD children also meet criteria for bipolar disorder, although the exact prevalence of this diagnosis in ADHD children is strongly debated. Regardless of prevalence, this is a severely impaired group of ADHD children, with high rates of aggression and psychiatric disorder in their families. The comorbidity of ADHD and major depression is much less studied, and few firm conclusions can be made about it. Finally, about 20%-25% of ADHD children meet criteria for a learning disorder, but learning disorders appear to be independent of ADHD.

Adolescent↗
PubMed1997

Measuring inhibitory control in children.

The Stop Signal Task is a measure of inhibitory control in which subjects must press a button in response to a stimulus. On certain trials, the subject receives a second stimulus (the Stop Signal) after the primary stimulus and must withhold his/her response during those trials. The onset of the Stop Signal is varied, sometimes coming immediately after the primary stimulus (inhibition is easy); at other times, the Stop Signal arrives quite late, making inhibition difficult. Results from the Stop Signal Task were obtained from children with attention-deficit/hyperactivity disorder (ADHD) and from controls; children with ADHD had significantly more difficulty inhibiting their responses than did controls. In a second study, results from the Stop Signal Task were obtained from a large sample of both behaviorally disturbed and community children; variables from the Stop Signal Task correlated well with both laboratory observations and teacher ratings of inattention and hyperactivity.

Anxiety Disorders↗
PubMed1996

An open trial of venlafaxine in the treatment of attention-deficit/hyperactivity disorder in children and adolescents.

A 5-week open trial of venlafaxine was conducted in 16 children and adolescents (mean age 11.6 years) with attention-deficit/hyperactivity disorder (ADHD) in order to estimate the appropriate dosage range and to determine the extent of side effects. Subjects were evaluated using a structured clinical interview and a computerized diagnostic assessment, and subjects diagnosed with ADHD and without comorbid depression were asked to enter the study. Conners Parent Rating Scale (CPRS) and Conners Continuous Performance Test (CPT) were performed at baseline and at the end of the 5-week trial. Two subjects were lost to follow-up. Of the remaining 14 patients, 7 subjects displayed a decrease of at least one standard deviation from their baseline on one of the CPRS subscale scores and had subjective reports from parents of improved behavior. There were no statistically significant effects of venlafaxine on reaction times or on the number of commission and omission errors on CPT. Three ADHD subjects displayed a worsening of their hyperactivity and required discontinuation of venlafaxine, and nausea led to drug discontinuation in 1 patient. The mean daily dose of venlafaxine was 60 mg (1.4 mg/kg), administered 2-3 divided doses, there were no effects on blood pressure or heart rate. In this sample, low doses of venlafaxine appeared to be effective in reducing behavioral but not cognitive symptoms of ADHD in 7 of 16 children and adolescents (44%), and adverse effects were not tolerable in 4 of 16 patients (25%). These preliminary results suggest that venlafaxine may aggravate symptoms of hyperactivity, consistent with the behavioral activation reported with fluoxetine and sertraline in children.

Adolescent↗
PubMed1996

Catecholamines in attention-deficit hyperactivity disorder: current perspectives.

OBJECTIVE: To provide an update on the "catecholamine hypothesis" of attention-deficit hyperactivity disorder (ADHD). METHOD: Recent work examining the measurement of the norepinephrine, epinephrine, and dopamine systems in ADHD and normal subjects is reviewed and discussed in the context of recent neuroimaging and animal studies. RESULTS: While data clearly indicate a role for all three of the above neurotransmitters in ADHD, a hypothesis suggesting "too much" or "too little" of a single neurotransmitter will no longer suffice. The central norepinephrine system may be dysregulated in ADHD, such that this system does not efficiently "prime" the cortical posterior attention system to external stimuli. Effective mental processing of information involves an anterior "executive" attention system which may depend on dopaminergic input. The peripheral epinephrine system may be a critical factor in the response of individuals with ADHD to stimulant medication. CONCLUSION: A multistage hypothesis is presented which emphasizes the interaction of norepinephrine, epinephrine, and dopamine in modulation of attention and impulse control.

Attention Deficit Disorder with Hyperactivity↗
PubMed1994

Urinary catecholamines in attention-deficit hyperactivity disorder with and without comorbid anxiety.

OBJECTIVE: To determine whether there are differences in noradrenergic or adrenergic functioning in children with attention-deficit hyperactivity disorder (ADHD) with and without anxiety. METHOD: ADHD children with and without a comorbid overanxious (ANX) disorder were compared to each other and to normal controls in terms of 2-hour urinary excretion of norepinephrine (NE), epinephrine (EPI), and their metabolites. All subjects performed a fixed series of mentally stressful tasks during the collection period. RESULTS: Children with ADHD, regardless of comorbid anxiety, excreted more normetanephrine (NMN), the chief extracellular metabolite of NE, than controls, as well as more vanillylmandelic acid. Children with ADHD alone had lower NE/NMN and EPI/metanephrine ratios compared to controls. Children with ADHD/ANX excreted more EPI than ADHD children without anxiety. CONCLUSIONS: Children with ADHD may have a higher tonic activity of the noradrenergic system than controls, while children with comorbid ADHD/ANX may be differentiated from those with ADHD alone by higher adrenergic activity.

Anxiety Disorders↗
PubMed1993

Classical conditioning in children with attention deficit hyperactivity disorder (ADHD) and anxiety disorders: a test of Quay's model.

Quay (1988) put forward a model of childhood mental disorders based on Gray's (1982) theory that there exists within the brain a behavioral inhibition system (BIS), which processes signals related to aversive or punishing stimuli. According to this model, children with attention deficit hyperactivity disorder (ADHD) show lower than optimal levels of activity in this system, which leads to less responsiveness at a physiological level to signals related to punishment. Children with ADHD and controls were compared on a classical conditioning paradigm. Skin conductance and cardiac responses were measured in response to a conditioned stimulus that had been paired with an aversive unconditioned stimulus. There were no differences between the groups, suggesting that, in terms of classical conditioning, ADHD children are equally responsive to signals related to punishment as controls.

Anxiety Disorders↗
PubMed1992

Comorbidity of attention-deficit hyperactivity disorder and overanxious disorder.

One hundred seven preadolescent children who meet criteria for attention-deficit hyperactivity disorder (ADHD) were further diagnosed by structured interview with regard to oppositional defiant disorder, conduct disorder, and overanxious disorder (ANX). The ADHD population was subdivided into those with and without a comorbid ANX, and the two ADHD groups were compared with each other and a control group in terms of teacher ratings, behavioral observations during an academic task, and the Inhibition version of the Continuous Performance Test. The results suggested that ADHD/ANX children may be less impulsive and/or hyperactive than those children with ADHD alone though they remain more impaired than controls. There was also a trend for the comorbid group to show fewer conduct disorder symptoms. The implications of comorbidity for the study of both ADHD and ANX are discussed.

Anxiety Disorders↗
PubMed1992

Neurochemistry and child and adolescent psychiatry.

This article reviews some of the neurochemistry and neurophysiology of three neurotransmitters: dopamine, norepinephrine, and serotonin. These neurotransmitters are selected because they appear to be involved in the regulation of several important behavioral systems that help regulate the interaction of the organism with its external environment, because many of the psychotropic drugs' modes of action may be result from their effects on these neurotransmitter systems, and because the majority of neurochemical studies in child psychiatry have focused on these three neurotransmitters. After the review of the neurotransmitter systems, neurochemical studies in several child psychiatric disorders are reviewed to illustrate possible biochemical/behavioral relationships in child psychiatry.

Adolescent↗
PubMed1991

A reply to critics of using stimulants to treat attention deficit hyperactivity disorder.

The lay press has paid increasing attention, much of it negative and distorted, to the use of stimulants for treatment of attention deficit hyperactivity disorder (ADHD). Examination of the points in the antistimulant arguments finds no support for any of them in the scientific literature. Physicians should not feel defensive about using stimulants for treatment when proper indications are present. This article will assist the primary care practitioner in answering parents' questions on these issues.

Attention Deficit Disorder with Hyperactivity↗
PubMed1991

Attention-deficit hyperactivity disorder: a clinical review.

Attention-deficit hyperactivity disorder is a common psychiatric disorder, with onset before age seven. The diagnosis is based on a careful history and standardized rating scales, and stimulant medications remain the drugs of choice. Children who do not respond to stimulants, or who have other significant psychiatric disorders, should be referred to appropriate mental health professionals.

Attention Deficit Disorder with Hyperactivity↗
PubMed1989

Effect of anxiety on cognition, behavior, and stimulant response in ADHD.

The effect of the comorbidity of overanxious disorder (ANX) in attention deficit hyperactivity disorder (ADHD) on laboratory measures of behavior, cognition, and stimulant response was examined. Seventy-nine children who met DSM-III-R criteria for ADHD were tested further for an oppositional defiant disorder (ODD), conduct disorder (CD), or ANX. Subjects with comorbid ANX showed less impulsiveness on a laboratory measure of behavior and had longer, sluggish reaction times on the Memory Scanning Test than those without ANX. ADHD subjects with comorbid ANX were less frequently diagnosed as CD. Forty-three of the subjects completed a double-blind trial of methylphenidate; subjects with comorbid anxiety had a significantly poorer response to the stimulant than those without anxiety, while the comorbidity of ODD or CD did not affect stimulant response. The results suggest that ADHD with comorbid ANX may represent children with primary anxiety who develop secondary inattentiveness, or they may represent a different subtype of ADHD, perhaps similar to the condition of attention deficit disorder without hyperactivity under DSM-III.

Anxiety Disorders↗
PubMed1988

DBH, MHPG, and MAO in children with depressive, anxiety, and conduct disorders: relationship to diagnosis and symptom ratings.

Plasma 3-methoxy-4-hydroxyphenylglycol (MHPG), plasma dopamine-beta-hydroxylase (DBH) activity, and platelet monoamine oxidase (MAO) were obtained in 42 boys (7-14 years old) consecutively evaluated at a community mental health clinic. The boys were diagnosed according to DSM-III criteria by a child psychiatrist using a semistructured interview with the parent and child. The Revised Behavior Problem Checklist (RBPC) and the Revised Children's Manifest Anxiety Scale (RCMAS) were consecutively obtained on the last 24 subjects. No relationship of any of the plasma measures was found with respect to the DSM-III diagnoses. Plasma MHPG was positively correlated with the parent's rating of the child's anxiety on the Anxiety-Withdrawal factor of the RBPC. Plasma MHPG as well as platelet MAO activity, correlated positively with the child's self-rating of anxiety on the RCMAS. Children classified by the RBPC as having high conduct symptoms and low anxiety symptoms had significantly lower plasma MHPG than those subjects with low conduct problems and high anxiety. Platelet MAO activity was found to be negatively correlated to the child's score on the Lie Scale of the RCMAS.

Adolescent↗