Once again, this reflected changes in the understanding and conceptualization of the disorder. The applicability of the current diagnostic criteria for young people with the disorder can be questioned.
Neuroanatomical theories
- Frontal lobe and parietal lobe theories 41
- Famil y history studies
- Twin studies
- Adoption studies
Barkley (1990) suggested that up to 32% of parents of children with ADHD also show symptoms of the disorder. Of the many criticisms leveled against earlier studies, perhaps the most pertinent relates to the issue of comorbidity. These studies are based on the hypothesis that there is likely to be a higher prevalence of the disorder among monozygotic (identical) twins than dizygotic (fraternal) twins because monozygotic twins have identical genetic material.
Adoption studies have made important contributions to the understanding of the etiology of the disorder. This implies that the biological parents of the adopted children were also likely to exhibit ADHD symptoms (Silver, 1992, as cited in Lerner, et al, 1995).
Neuropsychological evidence for ADHD
The limitations of neuropsychological
Rather, this section will examine issues that are of specific relevance to neuropsychological assessment and adolescents who meet diagnostic criteria for ADHD. i) Similar to most research on ADHD, neuropsychological studies have been done primarily on children who were diagnosed with ADHD. Relatively few studies have been conducted on adolescents who meet diagnostic criteria for the disorder (Seidman, et al., 1997). As a result, some of the measures used for children have yielded very different and mixed data when used for this group of adolescents. ii) Different versions of tests can produce conflicting results using the same sample group (Barkley, et al., 2001).
This has implications not only for the interpretation of results, but also for the understanding of possible etiologies. For example, Barkley, Grodzinksy, and DuPaul (1992) argue that although there is evidence to suggest frontal lobe deficits in children diagnosed with ADHD, the results obtained are highly dependent on the measures used.
Neuropsychological characteristics of ADHD
- Neuropsychological deficits across all
- Neuropsychological characteristics
In contrast to previous studies suggesting difficulties on tasks assessing working memory in children with ADHD (Grodzinsky & Diamond, 1992; Mariani & Barkley, 1997, as cited in Barkley, et al., 2001) these adolescents diagnosed with ADHD did not show deficits in general. working memory. In other words, the working memory tasks may not have comparable difficulty to the other tasks used in this study, in which group differences emerged. This supports the finding of an earlier study by Malone & Swanson (1993, as cited in Brodeur & Pond, 200 I) and implies that impairment in selective attention may exist.
Carlson, Lahey, and Neeper (1986) found no significant differences between ADDH and ADD/noH subtypes based on DSM-ill categorization. Another study by Schaughency et al. 1989) also found no differences between these subtypes using the Luria-Nebraska Neurological Battery - Children's Revision (LNNB-CR). However, in this case none of the subtypes differed from the normal control group (Barkley, et al. 1992).
Summary
They found that children with ADHD-IA and ADHD-C had similar profiles of impairment in inattention, which was different from the ADHD-III subtype, which showed no impairment in inattention. However, given the complexity of the neurochemical systems, it seems quite unrealistic to expect medication to completely eradicate all problems associated with ADHD. The evidence presented in this chapter supports Liemkuhler's (1994) argument for a neural dysfunction and, more specifically, a neurochemical deficit in ADHD as observed in problems in neuropsychological functioning.
Based on these arguments, one could assume that children and adolescents with ADHD are likely to share similar personality traits, which could lead to the development of the personality styles proposed by Liemkuhler (1994). This hypothesis is explored in more detail in Chapter Four.
Introduction
The mean plots for the research group and the control group based on the results of the ANOVA are depicted in Figure 6.3. Significant correlations between some of the five personality scales were also found for the research group and for the control group. The author suggests that these results can be interpreted in two ways. Forty percent of the research group, compared to only four percent of the control group, scored very high on the Neuroticism scale.
More members of the research group scored on the high scale than did members of the control group on the Extraversion scale. Sixteen percent of the research group scored in the very high range compared to only four percent of the control group.
Rationale for the choice of personality development
Procedure during testing
The school psychologist assisted with the initial set-up by arranging the participants' seating according to the groups they had been assigned. However, the participants were not informed of the rationale for such a division. Due to the anonymous nature of the test, identification letters (E=experimental group, C=control group) were indicated at the top right of each test booklet when participants were seated. This was done by the school psychologist, who could easily identify participants from each group. Two participants from the experimental group were absent, reducing the number of experimental group members to twenty-five. All twenty-six control group participants were present.
It was observed that the experimental group as a whole not only took longer to complete the test, but also asked more questions. More errors were made by members of the experimental group as indicated by the number of changed responses (participants were asked to cross out . errors and not delete them). Participants were allowed to leave once they had completed the test.
Scoring
Statistical analysis
Summary
Introduction
Descriptive Statistics
- Gender and age
- Sample size
- Means and standard deviations across groups
- Distribution ofT-score ranges across groups
1999). The research group in this study was 96% male, which can be argued to be similar to the prevalence trends observed in the general population. The following box plots show the distribution of standardized scores across all five personality scales for each group. It is useful because it also shows the variance from the mean for each personality scale. Box diagrams provide an easy way to represent the profile of the five scales of each group. It is encouraging to note that there is only one outlier on the Extraversion scale (raw score = 13, standardized T-score = 25 [very low]).
For the control group, the extraversion scale contains one outlier (T-score = 34, very low) and the openness scale contains two outliers (T-score = 30, very low; T-score = .58, high). This may indicate a greater variance of the results in the control group than in the research group. It shows that the research group scored high to very high on the neuroticism and extraversion scales, while the control group scored high on the agreeableness and conscientiousness scales.
Inferen tial Statistics
One way ANOVA
A one-way analysis of variance (ANDVA) was computerized to determine whether any significant statistical difference exists between groups and within groups using the means of the five personality scales, first from the research group and second from the control group. The Levene test for homogeneity of variance for the research group indicated a significant difference in the variance of the five personality scales in this group (p= .004). The ANOVA for the research group yielded a significant result (F = 3.885 »Fce = .005), indicating that the five personality scales have different means.
ANOVA for the control group gave a significant result (F=8.287 .. gt; Fa= 0.000). A summary of the ANOVA calculations is shown below. Again, Bonferroni's multiple comparison was computed to determine where the differences in significance were in the control group. The results showed that the mean difference is significant at the .005 level between the following personality scales: neuroticism and extraversion (mean difference significance = .047), neuroticism and conscientiousness (mean difference = -6.6000, significance = .001), extraversion and openness (mean difference = 5.7600, significance = .005), openness and agreeableness (mean difference in significance = .012), and.
The factorial ANOVA
The NEOAC compares all scores from a given personality scale to four other personality scales, regardless of whether the scores belong to a study or a control group. This could indicate whether the scores for any individual personality scale were significantly different from the other four personality scales and perhaps indicate a trend in personality development. GROUP compares the results of all five personality scales of the research group with the results of all five personality scales of the control group. This is obviously important to determine whether there are significant differences in personality styles between the research and control groups.
Non-parametric (distribution-free) tests, such as the t-test, were conducted but were not included in the results for two main reasons. Results indicated significant interactions between groups for the following scales: Extraversion and Neuroticism (significance = .012), Extraversion and Openness (significance = .000), Agreeableness and Openness (significance = .004) Conscientiousness and Neuroticism (significance = .030) and Conscientiousness and openness (mean= .000).
Relationships
Second, in addition to being less rigorous than parametric tests, there may be virtually no chance of detecting a significant difference, even if such a difference exists, because the family-use error rate increases whenever a. ANOVA may not only be considered statistically more powerful, but it reduces the possibility of statistical errors confounding the results. T-test results did not yield significant results.
Summary
On the other hand, 56% of the control group scored high compared to 28% of the research group. This may be a reflection of the challenges and difficulties associated with adolescence in general. Neither group achieved a very high range. Only four percent of the research group and eight percent of the control group scored high. None of the research group scored in the high to very high range on the agreeableness scale, as opposed to twenty percent of the control group.
The result of the one-way ANOYA yielded significant results for the differences between the personality scales for the research group (significance=.004) and the control group (significance=.000) separately. The facets contained in each NEO FFI personality scale are measures of these traits. Family instability can be considered one of the factors that put adolescents at risk for the development of clinical syndromes.
Unfortunately, this study did not reveal how many members of the research group were taking medications or have used medications in the past.
