1. Nonverbal Learning Disorder WAIS-IV Profiles in Anxiety Disorders
D. KennethMontfort
Fielding Graduate University
Ursula Alford
Amy Anderson
Raymond C. Hawkins, II Fielding Graduate University
University of Texas at Austin
AndresTapia
Darrell Stiffey
NCS Pearson
Abstract
Sample Description
Results
Discussion cont.
The sample comprised Pearson WAIS-IV archival data from adults with anxiety disorders (n=68), current major depression without co-morbid anxiety (n=155), and a non-clinical comparison group (n=839). No significant demographic differences were found between the anxiety and depression groups.
Previous research has noted an association between Nonverbal Learning Disorder (NVLD) and anxiety disorders, particularly GAD and OCD ruminations. Here we attempt to replicate this finding using the WAIS-IV anxiety and major depression clinical standardization groups.
The proportions of NVLD and Control profiles differed significantly between the Anxiety Group (23 NVLD, 6 Control) and the Depression Group (35 NVLD, 25 Control) and the Non-Clinical Comparison Group (199 NVLD, 182 Control). Applying more stringent NVLD criteria (VCI-PRI >= 10, plus Vocabulary score exceeding at least two of the following: Block Design, Coding, Matrix Reasoning, Visual Puzzles, by >= 3 scale score units) attenuated but did not remove these between group differences, with the Anxiety Group still showing more NVLD profiles (13) than Control profiles (6) relative to the Depression Group (25 NVLD, 25 Control) and the Non-Clinical Comparison Group (102 NVLD, 182 Control). Within the anxiety group, the NVLD cases were demographically similar to the control cases.
Study 1 examined the frequency with which each type of extreme difference (at least ten points’ difference) in verbal comprehension and perceptual reasoning occurred (Table 1). A chi square goodness of fit test showed that the NVLD profile occurred more frequently in the anxiety group than in the depression group or in the normative sample (chi-square (2) = 8.35, p = .015). The anxiety group showed greater than expected incidence of the NVLD profile than did either the depression or normative groups.
Study 2 utilized the Stringent NVLD profile, which added the criterion that considered differences between vocabulary and each of the perceptual reasoning subtests. The Control profile criterion in Study 2 was unchanged from that of Study 1. When the more strict criteria for NVLD were applied, a significant difference in frequencies between the diagnostic groups occurred (chi-square (2) = 10.47, p = .005). Table 1 shows the frequencies used in calculating this statistic.
Another possible reason for a lack of NVLD representation in the depression group in the present study may be that individuals with depression may be less likely to be verbally productive, and therefore may be less likely to score higher on VCI than PRI. Further studies should investigate whether the severity of depression is correlated with the frequency of the NVLD profile.
Overall these findings provide more evidence for the hypothesis that nonverbal learning disorder may be a neurocognitive endophenotype for anxiety disorders. This vulnerability may be the propensity individuals with the NVLD profile to have obsessional worries (similar to OCD) and an over-activation of verbal linguistic processing that is associated with verbal rumination. The use of the WAIS-IV NVLD criteria may be helpful to assess the underlying neurocognitive mechanisms for anxiety in adults. Additionally, this study also makes a case for combining neurocognitive and CBT assessment to assist clinicians in developing more accurate case conceptualizations and evidence-based interventions.
Introduction
Method
Participants from the original WAIS-IV standardization sample (NCS Pearson, 2008) were included in the present study if they were in the original normative, anxiety or depression sample groups, and if they demonstrated a difference of 10 points or more between VCI and PRI scores. In study 1, we examined the frequency with which each diagnostic group showed either the NVLD profile (VCI at least 10 points higher than PRI) or the Control profile (PRI at least 10 points higher than VCI). Study 2 also looked at the same frequencies, but with a more stringent definition of NVLD criteria: at least a 10 point difference favoring VCI, and 3+ point difference favoring vocabulary over block design, matrix reasoning or visual puzzle subtest scores.
In both studies, chi-square tests were used to determine whether the NVLD profile occurred more often than the Control profile in participants with anxiety disorders in comparison to participants with depression and participants with no diagnosis.
Nonverbal learning disorder (NVLD) is characterized by right hemisphere deficits that impair coordination, spatial awareness, perceptual reasoning skills, mental flexibility, and the ability to negotiate novel stimuli/situational demands (Rourke, 1988; Semrud-Clikeman & Hynd, 1990). These difficulties often have damaging effects on interpersonal relationships, social, and vocational skills.
While the majority of current nonverbal learning disorder (NVLD) literature is focused on children, empirical studies with adults show NVLD presentation results in social withdrawal and internalized emotional turmoil (Dugbartey, 2000; Kowalchuck & King, 1989).
Because NVLD involves a relative strength in verbal learning (Dugbartey, 2000; Rourke, 1988), this is the primary means of processing. Borkovec et al. (1990, 2004) propose that linguistic thought is the primary mechanism of worry. Thus, individuals with NVLD would be expected to have high rates of anxiety and to use their linguistic skills in a detrimental manner to perpetuate “worry thoughts.” NVLD has been shown to overlap with GAD criteria in other studies (Hawkins, Harte, & Lopez, 2010).
We hypothesize that the proportion of the NVLD profile in adult populations using the differential abilities on the WAIS-IV (higher verbal index than perceptual reasoning index) will be greater in the anxiety disorder group than in the normative group, as found in previous studies.
The current study is similar in design to a previous study by the current researchers examining the prevalence of NVLD criteria in WAIS-IV standardization data (Anderson, Alford, et al., 2013). In addition, this study uses subject data associated with depression and anxiety diagnostic criteria.
NVLD profile
VCI > PRI by 10+ points
Stringent NVLD profile
VCI > PRI by 10+ points, AND Vocabulary 3 or more points higher than any PRI subtests
Control profile
PRI > VCI by 10+ points
References
Anderson, A.B., Alford, U., Duffing, T., Stiffey, D., & Hawkins, R.C. II (April, 2013). Identifying nonverbal learning disability using the WAIS-IV: Establishing diagnostic differences. Poster presented at the Southwestern Psychological Association Conference, Ft. Worth, Texas
Borkovec, T.D., Alcaine, O., & Behar, E. (2004). Avoidance theory of worry and generalized anxiety disorder. In R.G. Heimberg, C.L. Turk, & D.S. Mennin (Eds.), Generalized anxiety disorder: Advances in research and practice. New York: Guilford Press.
Borkovec, T.D. & Hu, S. (1990). The effect of worry on cardiovascular response to phobic imagery. Behaviour Research and Therapy, 28,
Dugbartey, A.T. (2000). Nonverbal learning disability: Adult outcomes. Seminars in Clinical Neuropsychiatry,5,
Hawkins, R.C. II, Harte, C. & Lopez, M. (2010). WAIS differential abilities and generalized anxiety disorder. Poster presented at the Association for Psychological Science Convention, Boston, MA.
Kowalchuk, B. & King, J.D. (1989). Adult suicide versus coping with nonverbal learning disorder. Journal of Learning Disabilities, 22, p
Psychological Corporation. (2008). Technical and interpretive manual for the WAIS-IV. San Antonio, TX: NCS Pearson.
Rourke, B.P (1988). The syndrome of nonverbal learning disabilities: Developmental manifestations in neurological disease, disorder, and dysfunction. Clinical Neuropsychology, 2,
Semrud-Clikeman,M. & Hynd, G. (1990). Right hemispheric dysfunction in nonverbal learning disabilities: Social, academic, and adaptive functioning in adults and children. Psychological Bulletin 107(2),
Discussion
Table 1: NVLD Frequencies
Participants in the WAIS-IV clinical standardization group diagnosed with anxiety disorders were significantly more likely to display the NVLD profile, using both broadly and strictly defined WAIS-IV criteria, as compared with the Control profile. This finding replicates an earlier study (Hawkins et al., 2010) that used a sample of clients with GAD who were receiving CBT in a graduate training clinic. Hawkins et al. also found that the frequency of the NVLD profile in a group with major depression was twice as likely as was the control profile, but this was not the case in the present study. This is perhaps because persons with comorbid anxiety were excluded from the depression group in the WAIS-IV standardization even though comorbidities were allowed in Hawkins et al. (2010).
Frequencies of NVLD and Control Profiles
by Diagnostic Group
Diagnostic Group
NVLD
NVLD (Strict)
Control
Anxiety
n=68 23
(33.8%) 13
(19.1%) 6
(8.8%)
Depression
n=155 35
(22.6%) 25
(16.1%)
Non-Clinical
n=839
199
(23.7%)
102
(12.2%)
182
(21.7%)
Acknowledgments
We would like to thank NCS Pearson, Inc. for granting us permission to use the WAIS-IV clinical and normative samples for these analyses.