Lynda J. Katz

The Utility of Neuropsychological Tests in Evaluation of Attention-Deficit/ Hyperactivity Disorder (ADHD) versus Depression in Adults

A comparison was made between adults with depression and with Attention-Deficit/ Hyperactivity Disorder (ADHD) on a battery of cognitive tests of attention span and memory. Both the ADHD and depression groups were subdivided with regard to comorbid depression in the ADHD group and developmental learning disorder in both groups. Utilizing Discriminant Function Analysis, it was found that variables derived from the California Verbal Learning Test, the Paced Auditory Serial Addition Test, and the Stroop Test discriminated among the various subgroups at a level significantly exceeding chance. However, although the great majority of the ADHD participants were correctly classified, there were numerous misclassifications among the depressed groups. It was concluded that the tests used were highly sensitive to ADHD, but were also sensitive to a subgroup of depressed individuals.

Processing Speed and Working Memory Performance in Those with Both ADHD and a Reading Disorder Compared with Those with ADHD Alone

In previous studies, children with both Attention-Deficit Hyperactivity Disorder (ADHD) and a Reading Disorder were found to have more difficulties with processing speed, working memory, and timed as opposed to non-timed executive functioning (EF) measures when compared with those with either disorder alone. The current study found that older adolescents and adults with both disorders also had more difficulties on processing speed and working memory measures than individuals who only had ADHD. There were no differences among non-timed EF scores. These results add support to the premise that common underlying features may be contributing to the high co-morbidity between these disorders and associated cognitive weaknesses.

Neuropsychological Differences Between College Students with Learning Disabilities and Those with Mild Head Injury

College students with learning disabilities (LD) and those with a history of mild head injury (MHI) are two groups whose learning problems are not adequately addressed. We administered a comprehensive battery of neuropsychological, psychological, and academic achievement tests to college students with learning problems (LD, n = 35; MHI, n = 25) and a control group (n = 22), and completed a series of discriminant function analyses. A combination of six neuropsychological and psychoeducational test variables produced statistically significant differences among the three groups. The instruments were sensitive to LD, MHI, and the differences between them. The students with LD performed poorly on linguistically oriented psychoeducational tests, whereas the students with MHI showed cognitive deficits in visual-spatial skills and in the areas of attention, memory, and novel problem solving. Differential interventions addressing these deficits appear to be indicated.

A Neuropsychological Approach to the Bannatyne Recategorization of the Wechsler Intelligence Scales in Adults with Learning Disabilities

An investigatwn was conducted of the diagnostic ability of the Bannatyne recategorization of the Wechsler Mult Intelligence Scale-Revised (WAIS-R) into spatial, verbal-conceptual, and sequential components for adults with learning disabilities. A comparison among neuropsychological, intelligence, and achievement test data was made to evaluate the applicability of this recategorization. The Luria-Nebraska Neuropsychological Battery (LNNB), the WAIS-R, and the Wide Range Achievement Test-Revised (WRAT-R) were administered to 103 adult subjects with learning disabilities. The LNNB scales were cluster analyzed, and cluster membership was cross-tabulated against WAIS-R, WRAT-R, and demographic data. The major findings were that (a) the mean scores fit the Bannatyne pattern in two of the four clusters; and (b) the Bannatyne pattern was found in only about 20% of the total sample. It was concluded that identification of the Bannatyne pattern is of diagnostic utility, but its absence is inconclusive.

The relationship of self-reported subclinical obsessive-compulsive symptoms and impulsivity among adults with AD/HD

This study examined the degree to which subclinical obsessive-compulsive symptoms (SOCS) among individuals with Attention Deficit/Hyperactivity Disorder (AD/HD) were associated with response inhibition difficulties on a performance-based test. Participants consisted of 64 adults with AD/HD who completed the Conner׳s Continuous Performance Test, Second Edition (CPT-II), Symptom Checklist-90-Revised (SCL-90-R), and the Brown Attention Deficit Disorder Scale (ADD Scale). Individuals with higher scores on the Obsessive-Compulsive Scale from the SCL-90-R made significantly more commission errors on the CPT-II; whereas other SCL-90-R scores did not demonstrate such a relationship. We did not find that SOCS were related to severity of AD/HD. These results supported the hypothesis that individuals with AD/HD with response inhibition difficulties tend to report more subclinical obsessive symptoms.

Allocentric but not egocentric visual memory difficulties in adults with ADHD may represent cognitive inefficiency

Attention Deficit Hyperactivity Disorder (ADHD) has often been conceptualized as arising executive dysfunctions (e.g., inattention, defective inhibition). However, recent studies suggested that cognitive inefficiency may underlie many ADHD symptoms, according to reaction time and processing speed abnormalities. This study explored whether a non-timed measure of cognitive inefficiency would also be abnormal. A sample of 23 ADHD subjects was compared to 23 controls on a test that included both egocentric and allocentric visual memory subtests. A factor analysis was used to determine which cognitive variables contributed to allocentric visual memory. The ADHD sample performed significantly lower on the allocentric but not egocentric conditions. Allocentric visual memory was not associated with timed, working memory, visual perception, or mental rotation variables. This paper concluded by discussing how these results supported a cognitive inefficiency explanation for some ADHD symptoms, and discussed future research directions.

Assessment and Planning for Psychosocial and Vocational Rehabilitation

The rehabilitation of persons with severe and persistent mental disorders that falls under the rubric of psychosocial rehabilitation has historically involved the worlds of mental health, vocational rehabilitation, and community programs. Although these entities had distinct functions in the past, it has become apparent that their efficacy hinges on a collaborative process based upon a biopsychosocial model.