Response to commentary on the multimodal treatment study of ADHD (MTA): mining the meaning of the MTA

In the December 2000 issue of the Journal of Abnormal Child Psychology, we published a set of papers presenting secondary analyses of the Multimodal Treatment Study of ADHD (MTA), and R. A. Barkley (2000) provided a commentary. A critique of the design of the study (MTA Cooperative Group, 1999) was presented based on a theoretical perspective of a behavioral inhibition deficit that has been hypothesized as the core deficit of ADHD (R. A. Barkley, 1997). The commentary questioned the design and analysis of the MTA in terms of (1) the empirical criteria for selection of components of behavioral (Beh) intervention, (2) the effectiveness of the Beh intervention, (3) the methods for analyses at the group and individual level, (4) implications of the MTA findings for clinical practice, (5) the role of genetics in response to treatment, and (6) the lack of a nontreatment control group. In this response, we relate the content of the papers to the commentary, (1) by reviewing the selection criteria for the Beh treatment, as outlined by K. C. Wells, W. E. Pelham, et al. (2000), (2) by addressing the myth that the MTA Beh treatment was ineffective (Pelham, 1999), (3) by describing the use of analyses at the level of the individual participant, as presented by J. S. March et al. (2000) and W. E. Pelham et al. (2000) as well as elsewhere by J. M. Swanson et al. (2001) and C. K. Conners et al. (2001), (4) by relating some of the suggestions from the secondary analyses about clinically relevant factors such as comorbidity (as presented by J. S. March et al., 2000) and family and parental characteristics (as presented by B. Hoza et al., 2000, S. P. Hinshaw et al., 2000, and K. C. Wells, J. N. Epstein, et al., 2000), (5) by discussing the statistical concept of heritability and the lack of a significant difference in the presence of ADHD symptoms in parents of the MTA families compared to parents in the classmate-control families (as presented by J. N. Epstein, et al., 2000), and (6) by acknowledging that an ethically necessary weakness of the MTA design is that it did not include a no-treatment control group. We discuss the use of secondary analyses to suggest how, when, and for what subgroups effectiveness of the Beh treatment may have been manifested. Finally, we invite others to use the large and rich data set that will soon be available in the public domain, to perform secondary analyses to mine the meaning of the MTA and to evaluate theories of ADHD and response to treatments.     

The effects of child sexual abuse: Comment on Rind, Tromovitch, and Bauserman (1998).

B. Rind, P. Tromovitch, and R. Bauserman (1998) examined the long-term effects of childhood sexual abuse (CSA) by meta-analyzing studies of college students. The authors reported that effects "were neither pervasive nor typically intense" and that "men reacted much less negatively than women" (p. 22) and recommended value-neutral reconceptualization of the CSA construct. The current analysis revealed numerous problems in that study that minimized CSA-adjustment relations, including use of a healthy sample, an inclusive definition of CSA, failure to correct for statistical attenuation, and misreporting of original data. Rind et al.'s study's main conclusions were not supported by the original data. As such, attempts to use their study to argue that an individual has not been harmed by sexual abuse constitute a serious misapplication of its findings.     

Short-term memory for simultaneously presented visual and auditory signals in the pigeon

A series of divided-attention experiments in which matching to the visual or auditory component of a tone-light compound was compared with matching to visual or auditory elements as sample stimuli were carried out. In 0-s delayed and simultaneous matching procedures, pigeons were able to match visual signals equally well when presented alone or with a tone; tones were matched at a substantially lower level of accuracy when presented with light signals than when presented as elements. In further experiments, it was demonstrated that the interfering effect of a signal light on tone matching was not related to the signaling value of the light, and that the prior presentation of light proactively interfered with auditory delayed matching. These findings indicate a divided attention process in which auditory processing is strongly inhibited in the presence of visual signals.     

Development of intersensory function: age-related differences in stimulus selection of multimodal compounds in rats as revealed by Pavlovian conditioning.

Preweanling and adult rats were exposed to Pavlovian stimulus pairings with lights, tones, and light-tone compounds as conditional stimuli (CSs). Tone intensity was varied. As was found in previous studies using flavor CSs, odor CSs, or both, in which significant overshadowing or potentiation occurred to an element of a compound, overshadowing was less likely and potentiation more likely for preweanlings than for adults. Several experiments supported the view that these effects reflect an age-related difference in the controlling properties of stimuli: Young rats are more disposed to encode multimodal compounds on the basis of amodal intensity, whereas their elders are more likely to encode modality-specific properties of light and sound. Differential reinforcement in the presence of lights, tones, and light-tone compounds made preweanlings' stimulus selection appear more adultlike and may be a cause of development of intersensory function.     

Extension of Feldt's approach to testing homogeneity of coefficients of reliability

Limitations and extensions of Feldt's approach to testing the equality of Cronbach's alpha coefficients in independent and matched samples are discussed. In particular, this approach is used to test equality of intraclass correlation coefficients.This work was supported by the National Institute of Mental Health Specialized Research Center Grant # MH-30854.     

Anxiety as a Predictor and Outcome Variable in the Multimodal Treatment Study of Children with ADHD (MTA)

Initial moderator analyses in the Multimodal Treatment Study of Children with ADHD (MTA) suggested that child anxiety ascertained by parent report on the Diagnostic Interview Schedule for Children 2.3 (DISC Anxiety) differentially moderated the outcome of treatment. Left unanswered were questions regarding the nature of DISC Anxiety, the impact of comorbid conduct problems on the moderating effect of DISC Anxiety, and the clinical significance of DISC Anxiety as a moderator of treatment outcome. Thirty-three percent of MTA subjects met DSM-III-R criteria for an anxiety disorder excluding simple phobias. Of these, two-thirds also met DSM-III-R criteria for comorbid oppositional-defiant or conduct disorder whereas one-third did not, yielding an odds ratio of approximately two for DISC Anxiety, given conduct problems. In this context, exploratory analyses of baseline data suggest that DISC Anxiety may reflect parental attributions regarding child negative affectivity and associated behavior problems (unlike fearfulness), particularly in the area of social interactions, another core component of anxiety that is more typically associated with phobic symptoms. Analyses using hierarchical linear modeling (HLM) indicate that the moderating effect of DISC Anxiety continues to favor the inclusion of psychosocial treatment for anxious ADHD children irrespective of the presence or absence of comorbid conduct problems. This effect, which is clinically meaningful, is confined primarily to parent-reported outcomes involving disruptive behavior, internalizing symptoms, and inattention; and is generally stronger for combined than unimodal treatment. Contravening earlier studies, no adverse effect of anxiety on medication response for core ADHD or other outcomes in anxious or nonanxious ADHD children was demonstrated. When treating ADHD, it is important to search for comorbid anxiety and negative affectivity and to adjust treatment strategies accordingly.     

Q‐sort methodology: Bridging the divide between qualitative and quantitative. An introduction to an innovative method for psychotherapy research

Q‐methodology offers unique opportunities for counselling and psychotherapy researchers and clinicians. It is an innovative technique capable of bridging the divide between clinical knowledge and the quantitative systematisation of it. It was initially developed by Stephenson as a data collection and data analytic method to empirically study human subjectivity. It was then extended by the British School to study shared viewpoints, thereby adopting a multi‐participant design and a highly unusual form of qualitative analysis. Finally, it was adapted by the Californian School for use as a standardised observer‐rated assessment tool. Its attractiveness stems from its aptitude to produce holistic data as it collects both quantitative and narrative data. This paper will provide an introduction to Q‐statistics and Q‐methodology (person‐centred) by contrasting it to R‐statistics and R‐methodology (variable‐centred). It will then provide an overview of the three schools of Q‐methodology and their various merits demonstrated with an example.