Comparison of Two Measures of Working Memory Impairments in 220 Adolescents and Adults With ADHD.

Objective: This study tests the hypotheses that (a) adolescents and adults with ADHD score lower on two normed measures of verbal working memory, relative to their overall verbal abilities, than the general population and (b) a specific story memory test is a more sensitive and relevant measure of working memory impairment than a numerically based test. Method: Scores on normed story memory and numerical memory tests of 220 adolescents and adults with ADHD were corrected for the individual's verbal abilities and compared with each other and national norms. Results: Participants with ADHD scored significantly below their verbal ability measure on both verbal and numerically based memory tests in comparison with national norms. Scores on verbal memory test were lower than scores for numerically based memory tests. Conclusion: This story memory test is a more sensitive measure of working memory impairments in adolescents and adults with ADHD than measures based on recall of numerical data.

Impact of atomoxetine on subjective attention and memory difficulties in perimenopausal and postmenopausal women.

OBJECTIVE: Perimenopausal and postmenopausal women frequently report midlife onset of impairments of attention, organization, and short-term memory. We sought to determine whether these cognitive symptoms in healthy women in the menopause transition without a history of attention-deficit/hyperactivity disorder (ADHD) would respond to treatment with atomoxetine (ATX), a medication demonstrated to be effective in reducing similar cognitive impairments in adults with ADHD. METHODS: Sixteen healthy women with complaints of midlife-onset subjective difficulties in memory and concentration/attention and without a history of ADHD or other psychiatric disorders were enrolled in a double-blind, placebo-controlled crossover study of ATX 80 mg/day. Treatment arms were 6 weeks long, separated by a 4-week washout. The Brown Attention Deficit Disorder Scale (BADDS) was used to systematically elicit self-report of perceived cognitive difficulties in executive function. Participants also underwent neuropsychological testing, behavioral assessments, and vital signs monitoring. RESULTS: Mean baseline BADDS scores were 37.9 for all 16 participants and 42.3 for the 12 who completed both arms of the study. Total BADDS scores decreased significantly from baseline during ATX treatment but not placebo treatment. ATX treatment was superior to placebo in reducing the BADDS working memory cluster score, whereas there was a trend for ATX superiority for the BADDS attention/concentration cluster score. ATX did not differ from placebo with respect to effects on neuropsychological tests, behavioral assessments, or cardiac vital signs. CONCLUSIONS: Perimenopausal and postmenopausal women presenting with midlife-onset subjective cognitive difficulties may experience significant subjective improvement in memory and attention/concentration with ATX treatment.

Executive function impairments in high IQ adults with ADHD.

OBJECTIVES: To demonstrate that high IQ adults diagnosed with ADHD suffer from executive function (EF) impairments that: a) can be identified with a combination of standardized measures and self-report data; and b) occur more commonly in this group than in the general population. METHOD: 157 ADHD adults with IQ >/= 120 were assessed with 8 normed measures of EF- 3 index scores from standardized tests of memory and cognitive abilities, and 5 subscales of a normed self-report measure of EF impairments in daily life. RESULTS: 73% of subjects were significantly impaired on >/= 5 of these 8 EF markers. On all 8 measures, incidence of these impairments was significantly greater than in the general population. CONCLUSION: High IQ adults with ADHD tend to suffer EF impairments that can be assessed with these measures; incidence of such impairments in this group is significantly higher than in the general population.

Striatal dopamine transporters correlate with simple reaction time in elderly subjects.

The decline in motor performance that accompanies advanced age has unclear neurobiological substrates but may relate, in part, to degeneration of the nigrostriatal dopamine system. This research tested the hypothesis that striatal dopamine transporter (DAT) availability in healthy elderly individuals was related to measures of motor performance. Thirty-six healthy volunteers (18 male, 18 female) who ranged in age from 68 to 88 (75.4+/-4.9 years) received a neuropsychological evaluation that included two primary motor measures (tested with dominant hand): (1) simple reaction time (SRT); and (2) finger tapping (FT). Subjects underwent SPECT scanning with [(123)I]2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([(123)I]beta-CIT) for measurement of striatal DAT availability. A ratio of specific to nondisplaceable brain uptake (i.e., radical V3 =[striatal-occipital]/occipital), a measure proportional to the binding potential (B(max)/K(D)), was derived. SRT was significantly correlated with striatal DAT availability with or without controlling for the contribution of age. However, contrary to hypothesis, FT was not correlated with striatal DAT availability. Comparison measures, including episodic memory and general intelligence, were also unrelated to striatal DAT availability. These results demonstrate that a loss of nigrostriatal dopaminergic function likely contributes to slowing of reaction speed with advancing age.

Assessment of short-term verbal memory impairments in adolescents and adults with ADHD.

The purpose of this study was to determine whether a brief measure of verbal memory can assess short-term verbal memory impairments relative to verbal abilities in adolescents and adults with Attention-Deficit/Hyperactivity Disorder (ADHD) and to ascertain whether significant differences between short-term verbal memory and verbal abilities are more common among persons with ADHD than in the general population. One hundred seventy-six adolescents and adults diagnosed with ADHD (DSM-IV criteria) were assessed with a measure of short-term verbal memory. The short-term verbal memory score of each subject was compared with the verbal abilities on two measures. Percentages of ADHD subjects with "significant discrepancy" between verbal IQ and short-term verbal memory were compared with the standardization sample for the verbal memory measure. A majority of adolescents and adults diagnosed with ADHD demonstrated significant discrepancy between performance on the short-term verbal memory measure and verbal IQ. The percentage of ADHD subjects with a significant discrepancy between these two measures greatly exceeded the percentage of persons in the general population showing such a discrepancy. This brief measure of short-term verbal memory may be a useful measure to include in a comprehensive assessment for ADHD symptoms in adolescents and adults. Replication in other groups of ADHD patients is needed to test the generalizability of the findings.

Unaltered dopamine transporter availability in adult attention deficit hyperactivity disorder.

OBJECTIVE: The authors examined whether patients with attention deficit hyperactivity disorder (ADHD) have altered striatal dopamine transporter levels, which may explain psychostimulant effects in this disorder. METHOD: Single photon emission computed tomography and [(123)I]2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([(123)I]beta-CIT) were used to assess dopamine transporter availability in nine adult patients with ADHD (eight of whom were stimulant naive) and nine age- and gender-matched healthy comparison subjects. RESULTS: Striatal [(123)I]beta-CIT binding did not differ significantly between the ADHD and comparison subjects. CONCLUSIONS: The findings suggest that a hypothesized dysregulation of dopamine function in ADHD does not entail altered dopamine transporter levels.