1Controlled evaluation of a neurofeedback training of slow cortical potentials in children with Attention Deficit/Hyperactivity Disorder (ADHD)

Abstract

Background: Although several promising studies on neurofeedback training in Attention Deficit/Hyperactivity Disorder (ADHD) have been performed in recent years, the specificity of positive treatment effects continues to be challenged.

Methods: To evaluate the specificity of a neurofeedback training of slow cortical potentials, a twofold strategy was pursued: First, the efficacy of neurofeedback training was compared to a group training program for children with ADHD. Secondly, the extent of improvements observed in the neurofeedback group in relation to successful regulation of cortical activation was examined. Parents and teachers rated children's behaviour and executive functions before and after treatment. In addition, children underwent neuropsychological testing before and after training.

Results: According to parents' and teachers' ratings, children of the neurofeedback training group improved more than children who had participated in a group therapy program, particularly in attention and cognition related domains. On neuropsychological measures children of both groups showed similar improvements. However, only about half of the neurofeedback group learned to regulate cortical activation during a transfer condition without direct feedback. Behavioural improvements of this subgroup were moderately related to neurofeedback training performance, whereas effective parental support accounted better for some advantages of neurofeedback training compared to group therapy according to parents' and teachers' ratings.

Conclusion: There is a specific training effect of neurofeedback of slow cortical potentials due to enhanced cortical control. However, non-specific factors, such as parental support, may also contribute to the positive behavioural effects induced by the neurofeedback training.

Figure 1

Design of the study

Figure 2

Changes of mean amplitudes between beginning and end of the training. Differences of the mean amplitudes between the beginning (double session 2–3) and the end (double-session 13–14) of the training during negativity or positivity trials in feedback and transfer conditions are represented in Figure 2. (N = 17)

Figure 3

Course of mean differentiation between positivity and negativity trials in double-sessions 7 to 14 of good and poor performers.

Figure 4

Mean differentiation in relation to changes of the Hyperactivity score. The scatterplot represents the mean differentiation between negativity and positivity trials (transfer condition, double-sessions 7 to 14) in relation to changes on the Hyperactivity subscale (FBB-HKS) (time 1 minus time 2) in good (N = 8) and poor performers (N = 9).