Effect of methylphenidate on motivation in children with attention-deficit/hyperactivity disorder.

The effects of methylphenidate (MPH) on motivation were examined using a progressive ratio (PR) task in children who were prescribed MPH for the treatment of ADHD. Twenty-one children, 7 to 12 years of age, completed two test sessions, one under the effects of medication and one not. During each session, children pressed a lever to earn nickel reinforcers, where the first press resulted in a reinforcer and 10 additional presses were required for each subsequent reinforcer. Children on MPH had a significantly higher breakpoint than when off medication. This MPH-associated increase in the breakpoint manifested as a significant decrease in the interresponse times (IRT). Further, MPH administration resulted in a significant decrease in IRT variability. In contrast, MPH administration had no significant effects on the means and variability of postreinforcement pause duration. These results suggest that MPH increased motivation in children being treated for ADHD. Further, the inability of MPH to significantly reduce postreinforcement pause duration while simultaneously decreasing IRTs suggests that while MPH may increase motivation to perform an ongoing task, it may have little effect on the initiation of that task.

Estimates of the validity and utility of the Conners' Continuous Performance Test in the assessment of inattentive and/or hyperactive-impulsive behaviors in children.

This study evaluated the validity and classification utility of the Conners' Continuous Performance Test (CCPT) in the assessment of inattentive and hyperactive-impulsive behaviors in children. Significant, positive correlations between the CCPT parameters and behavioral ratings of ADHD behaviors were hypothesized. In addition, it was hypothesized that the CCPT parameters would perform better than a random test (chance) and show fair to moderate utility of classification across the different indices. Participants were 104 children between 6 and 12 years of age who were referred for evaluation of attention problems. The first hypothesis was not supported. There were no significant, positive correlations between the CCPT parameters and parent and teacher ratings of inattentive and hyperactive-impulsive behaviors. The second hypothesis was only partially supported. The CCPT Overall Index and the Omission Errors (84th percentile cutoff) performed better than a random test; however, the utility of the CCPT Overall Index only ranged from poor to slight. Receiver operating characteristic analyses showed the accuracy of the CCPT to be low. The implications and limitations of this study and future research directions are discussed.

The use of AAP-recommended disciplinary practice guidelines among African American caregivers of children in Head Start programs.

OBJECTIVE: The American Academy of Pediatrics (AAP) recommends that parents not use harsh disciplinary practices. Previous studies have characterized the disciplinary practices of African American parents as harsh, with reliance on more aggressive techniques not currently recommended by the AAP. However, recent research has indicated more disciplinary practice diversity among African Americans. This study describes factors associated with the use of AAP-recommended disciplinary practices among lower-income African American caregivers of children in Head Start. METHODS: Subjects were caregivers of children at three Head Start sites. Participants were eligible for inclusion if the biological mother, biological father, or target child was identified as African American. Using consensus methods, responses to the Parental Discipline Methods Interview (PDMI) were described as consistent or inconsistent with AAP guidelines regarding use of negative disciplinary practices (e.g., spanking, yelling). Caregivers avoiding any of these inconsistent methods were referred to as "adherent." RESULTS: "Adherent" caregivers were older (32.5 years vs. 30.4 years) and had more education (86.0% vs. 75.4% high school graduates). They were also less likely to report that their child had behavioral problems (12.9% vs. 25.2%) or deficient social skills (1.7% vs. 8.0%). CONCLUSIONS: Lower-income African American caregivers were more likely to use disciplinary practices consistent with AAP guidelines if they had higher levels of education and were living in an urban setting. Caregivers describing their child as having fewer behavior problems, better social skills, or themselves as less stressed were also more likely to be "adherent."

Measuring the potential for child maltreatment: the reliability and validity of the Adult Adolescent Parenting Inventory--2.

OBJECTIVE: The field of child protection needs reliable and valid methods of assessing the potential for child abuse and neglect. The purpose of this study was to examine the psychometric properties of the Adult Adolescent Parenting Inventory--2 (AAPI-2), Form B, using a sample of 309 low-income, rural families in a southern state. METHOD: The AAPI-2 is a 40-item survey designed to assess the parenting and child rearing attitudes of adult and adolescent parent and pre-parent populations. Each of the five AAPI-2 scales was (a) examined using factor analysis in order to determine the unidimensionality of the scale, (b) evaluated based on estimates of the scales reliability in order to determine the consistency with which the construct was measured, and (c) when possible, examined to determine if it is related to other constructs in meaningful and expected ways. RESULTS: While the factor structure reported by the developer was not fully confirmed in this sample, there is some evidence that the instrument is measuring at least two of the constructs it purports to measure and that the total score may be useful. Correlations with other instruments measuring parenting behavior and child behavior were significant, and in the expected direction, offering some support for the validity of the AAPI-2. CONCLUSIONS: While the AAPI-2 appears to measure attitudes related to harsh or neglectful parenting, caution should be used in the interpretation of the individual AAPI-2 scales.

Estimates of the validity and utility of unstructured clinical observations of children in the assessment of ADHD.

The purpose of this prospective study was to examine the validity and diagnostic utility of unstructured clinic observations of attention deficit hyperactivity disorder (ADHD) behaviors in children. Results showed observations to be related to behavioral ratings of parents but not of teachers. The relationship between observations and parent ratings was stronger for hyperactive-impulsive than inattentive behaviors. The level of agreement between observations and classification of ADHD significantly exceeded chance levels only for parent measures of hyperactivity-impulsivity. Only parent measures predicted a diagnosis of ADHD at a rate that was significantly better than chance. Clinic observations were found to have consistently higher positive predictive power than negative predictive power. Clinical implications are discussed.

Effect of methylphenidate on time perception in children with attention-deficit/hyperactivity disorder.

The effects of methylphenidate (MPH) on performance of a time-production task were studied in 17 children with attention-deficit/hyperactivity disorder who participated in 1 test session on and 1 off MPH. Participants held a response lever down for at least 10 but no longer than 14 s. Administration of MPH had no effect on the number of correct responses or on the mean duration of lever holds. MPH administration significantly decreased timing response variability, increased holds of 10- to 11-s duration, and decreased lever holds of extremely short durations. These results indicate that administration of MPH resulted in more precise timing performance without changing the mean duration of lever holds, suggesting an enhancement in working memory.

Stimulant medication improves recognition memory in children diagnosed with attention-deficit/hyperactivity disorder.

The effect of stimulant medication on recognition memory was examined in 18 children with attention-deficit/hyperactivity disorder (ADHD). Recognition memory was assessed using a delayed matching-to-sample task at 6 delays ranging from 1 to 32 s. Each child was tested on 2 separate occasions, once 60 to 90 min after taking stimulant medication and the other at least 18 hr after taking medication. Children performed significantly better on medication than off. Stimulant administration significantly increased accuracy and the number of nickel reinforcers earned. Decreases in observing response latency and correct choice response latency occurred after taking stimulant medication. The results indicate that stimulant medication improved recognition memory for children with ADHD.