1. Nonverbal Learning Disorder as a Neurocognitive Endophenotype for Anxiety in Adults: Implications for CBT Assessment and Intervention
Raymond C. Hawkins, II
Fielding Graduate University
University of Texas at Austin
David Brown
Fielding Graduate University
Abstract
Sample Description
Results
Discussion cont.
These preliminary data from this training clinic sample do not substantiate that this NVLD pattern in neurotypical individuals is associated with greater perceived difficulties in interpersonal relationship or social role functioning than in the Control group. Furthermore, CBT functional assessment and manualized CBT interventions appear to be as effective with the NVLD group as with the Control group. There are obvious limitations of this study: a small clinical sample of WAIS cases was analyzed, none of the clients were referred for overt learning disorders (most had at least some college study), the presence of interpersonal relationship and/or social role problems often purported to characterize persons with nonverbal learning disorders was not rated by objective observers or collateral informants, and confirmatory neuropsycho-logical / psychoeducational measures of learning deficits were not obtained.
We do believe, though, that this nonverbal learning disorder pattern deserves further research study. Neurocognitive assessment and cognitive remediation may be a valuable adjunct to integrative cognitive-behavioral treatments, particularly when there are comorbid anxiety diagnoses.
Although we replicated an association between Nonverbal Learning Disorder (NVLD) and anxiety disorders, CBT was as effective in the NVLD group as in the Control group. Further research is needed to support NVLD as a neurocognitive endophenotype for adult anxiety.
The sample comprised 548 adults (mean age of years) receiving CBT assessment in the University of Texas Clinical Psychology Training Clinic, (368 of whom received manualized CBT interventions by second year graduate students). All clients sought treatment at our clinic primarily for anxiety problems or depression, not for learning disabilities. Wechsler Adult Intelligence Scale (WAIS-R, WAIS-III, or WAIS-IV) profiles were available for 174 of these clients (mean FSIQ of 110). Using the criteria described in the Method section, there were 39 NVLD cases (27 females, 12 males) and 22 control cases (13 females, 9 males).
Preliminary analyses did not reveal significant differences in age, gender, ethnicity, or FSIQ between the NVLD and Control groups. Next we examined the frequency of DSM anxiety related diagnoses within the NVLD and Control groups. Note that in most cases there was more than one DSM diagnosis per group, and for these analyses, anxiety diagnoses were tallied as present whether or not they were primary or secondary diagnoses. For the NVLD group (n=39) there were 13 with GAD, 11 with OCD, 26 with major depression, 15 with substance use disorders, 13 with social phobia, 10 with Panic Disorder (PD) (with or without agoraphobia, AG), 7 with PTSD, and 4 with Dysthymia. The corresponding numbers for the control group (n=22) were GAD (5), OCD (1), MDD (11), SUD (3), SP (11), PD with/without AG (8), PTSD (3), and Dysthymia (0).
Introduction
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).
Because NVLD involves a relative strength in verbal learning (Dugbartey, 2000; Rourke, 1988), this is the primary means of processing. Borkovec et al. (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; Hawkins, Ashworth, & Dilks, 2013; Montfort et al., 2013).
In this study we sought to determine (1) if NVLD would be associated with client reported quality of interpersonal relationships and social role performance and (2) if NVLD would be related to the outcomes of CBT in a training clinic with respect to improvements in target symptoms as well as to improvements in interpersonal relationships and social role performance.
Method
WAIS profiles were retrospectively scored for NVLD independent of knowledge of the DSM diagnoses. DSM diagnoses had originally been made using the SCID-I and SCID-II. Sheehan Disability Scales (SDS) scores yielded client ratings of quality of life / functioning in the areas of work, social / leisure, family, and overall (global ratings). Outcome Questionnaire (OQ 45.2) symptom distress, interpersonal relationships, and social role performance client-ratings were also available. In addition, Beck Scales (BDI, BAI, BHS, BSI) and additional domain specific CBT client self-report measures for various anxiety disorders were included in the database, along with the total number of CBT sessions for each case. Rourke’s criteria for NVLD were used (i.e., Verbal Intelligence Quotient (VIQ) or Verbal Comprehension Index (VCI) exceeding the Performance Intelligence Quotient (PIQ) or Perceptual Reasoning Index (PRI) by at least 10 scale score points, with high Vocabulary, Information, and Similarities subtest scores and low Block Design, Coding, and Arithmetic scores (3+ point difference between these high and low scores). For comparison purposes (as in Hawkins et al., 2010) we selected a Control group defined solely by a 10 point PIQ > VIQ (or PRI > VCI) difference.
There were no statistically significant differences
between the NVLD and the Control groups on these
baseline SDS and OQ scales. with respect to treat-
ment outcome, the average number of CBT treat-
ment sessions for the NVLD group (mean=12.2,
SD=7.3) and the Control group (mean=11.1, SD=
7.1) were not significantly different. Finally, the
averaged z scores for CBT target symptom outcome
measures did not differ significantly between the
NVLD group and the Control group at baseline
assessment (1.42 NVLD, 1.71 Control), or at end of
treatment (1.0 NVLD, .03 Control). 19 of 25 NVLD
treated cases showed CSC, vs. 14 of 16 Controls.
References
Anderson, A.B., Alford, U,, Duffing, T., Stiffey, D., & Hawkins, R.C. II (2013). Identifying nonverbal learning disability using the WAIS-IV: Establishing diagnostic differences. Poster presented at the Southwest Psychological Association Convention, Ft. Worth, TX.
Anderson, A.B., Waller, L., Rivera-Perez, Y. D., Stuffey, D., & Hawkins, R.C.II (2014). Nonverbal learning disorder WPPSI-IV profiles in autism spectrum disorders. Poster presented at the Texas Psychological Association Convention, Dallas, TX.
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.
Dugbartey, A.T. (2000). Nonverbal learning disability: Adult outcomes. Seminars in Clinical Neuropsychiatry, 5,
Hawkins, R.C. II, Ashworth, B., & Dilks, L. (2013). WAIS differential abilities and bipolar disorder, substance abuse, and generalized anxiety disorder diagnoses. Poster presented at the New England Psychological Association Convention, Bridgeport, CT.
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.
Montfort, D.K., Alford, U., Anderson, A., Tapia, A., Stiffey, D., & Hawkins, R.C. II (2013). Nonverbal learning disorder WAIS-IV profiles in anxiety disorders. Poster presented at the Texas Psychological Association Convention, Austin, TX.
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),
Stiffey, D.C, Jr., Carlson, H.I., Montfort, N.T., Martinez, S.T., Brookshire, B., & Hawkins, R.C. II (May, 2010). Identifying nonverbal learning disability using the WISC-IV: Identifying diagnostic differences. Poster presented at the Association for Psychological Science Convention, Boston, MA.
Discussion
Clients with anxiety disorders were significantly more likely to display the NVLD profile, using Rourke’s WAIS criteria, as compared with the Control profile. This finding replicates earlier studies (Hawkins et al., 2010; Hawkins et al., 2013; Montfort et al., 2013) This overrepre-sentation was largest for OCD, GAD, substance use disorders with comorbid anxiety, Major depression with comorbid anxiety, and PTSD. Interestingly, the frequency of panic disorder (with or without agoraphobia) and social phobia did not differ between the NVLD and Control group. We believe that this association of NVLD pattern on the WAIS may be a potential neurocognitive endophenotype vulnerability factor for anxiety comorbidity in adults, particularly for worry and obsessional tendencies. We (Anderson et al., 2013, 2014; Stiffey et al., 2010) have found that children and adults diagnosed with Aspergers syndrome are more likely to display the NVLD profile on the WPPSI, WISC, and WAIS, but not children or adults with non-Aspergers autism spectrum disorders. Interestingly, Borkovec and colleagues (2004) have argued that excessive verbal linguistic processing and diminished activation of emotional processing from directly facing perceived threats is a viable causal mechanism maintaining GAD, and that individuals with chronic GAD and worry rumination have social deficits that may interfere with their response to standard CBT for GAD.
NVLD profile
WAIS VCI > PRI by 10+ points, AND Vocabulary 3 or more points higher than any PRI subtests
Control profile
PRI > VCI by 10+ points
Acknowledgments
Chi-square tests were used to determine whether
the NVLD profile occurred more often than the
Control profile in participants with anxiety disorders.
T-tests for independent groups were conducted to
look for statistically significant differences between
the NVLD and Control groups on the OQ-45,2 sub-
scores an d the CBT domain-specific target symptom
outcome measures at baseline and at the end of
treatment. Averaged z scores and number showing
clinically significant change (CSC) were compared.
We thank Marttita Lopez, Ph.D., Michael Telch, Ph.D., David Collins, Ph.D., and all graduate student clinicians who supervised, screened, assessed, and treated these clients. We also thank all clients who took part in this study who agreed to have their data de-identified and archived for research purposes.