After discussing implications for research in the previous section, this section addresses implications for clinical and educational practice. The main results of the current study revealed (1) that sustained attention or off-task behavior might be a core deficit in ADHD and (2) that there are indirect effects of basal cognitive functions (e.g., sustained attention, behavioral inhibition) on ADHD through higher cognitive functions (e.g., risky decision-making). Thus, based on these results two types of trainings or intervention programs could be suggested.
First, trainings or intervention programs could try to improve ADHD symptoms in children by treating a deficit in sustained attention. Several training programs seeking to improve sustained attention have been developed including the practice of cognitive tasks like the CPT (Rabiner, Murray, Skinner, & Malone, 2010; Shalev, Tsal, & Mevorach, 2007; Tamm, Epstein, Peugh, Nakonezny, & Hughes, 2013; for an overview see Sonuga-Barke, Brandeis, Holtmann, & Cortese, 2014), self-alerting procedures (O’Connell et al., 2008; Robertson, Tegnér, Tham, Lo, & Nimmo-Smith, 1995), and intensive meditation (Chambers, Lo, & Allen, 2008; MacLean et al., 2010; but see Chiesa, Calati, & Serretti, 2011). However, the trainings varied in in duration and intensity and only few training programs have been tested in children with ADHD (Sonuga-Barke et al., 2014). Parents reported significantly lower ratings of ADHD and inattentive symptoms in particular, after an eight-week training period (Shalev et al., 2007) or 16 bi-weekly sessions (Tamm et al., 2013) of interventions which were designed to practice sustained, selective, alternating, and divided attention through visual and auditory stimuli.
Further evidence for the effectiveness of sustained attention trainings comes from research on neurofeedback. During neurofeedback participants learn to control their brain electric activity through operant conditioning (Moriyama et al., 2012). For instance, to foster sustained attention children learned to control their theta-to-beta ratio by controlling a dolphin character on a computer screen. When the theta-to-beta ratio decreased reflecting good sustained attention, the dolphin swam down to the button of the ocean and the child received points. In contrast, when the child became distracted, the dolphin swam back to the surface of the ocean (Steiner, Frenette, Rene, Brennan, & Perrin, 2014a, 2014b). Neurofeedback has been shown to improve sustained attention (Wang & Hsieh, 2013) and several studies claimed the effectiveness of neurofeedback in ADHD (Gevensleben et al. 2009; Steiner et al., 2014a, 2014b; for reviews see Lofthouse, Arnold, Hersch, Hurt, & DeBeus, 2012; Moriyama et al.,
2012; for a meta-analysis see Arns, de Ridder, Strehl, Breteler, & Coenen, 2009). However, effectiveness is debated due to a lack of double-blind placebo-controlled studies (Vollebregt, van Dongen-Boomsma, Slaats-Willemse, & Buitelaar, 2014) suggesting that neurofeedback might not be more effective than a placebo-condition (Arnold et al., 2013).
Recently, it has been tried to implement attentional trainings (Steiner et al., 2014b; Steiner, Sheldrick, Gotthelf, & Perrin, 2011) and neurofeedback in the school context (Steiner et al., 2014a, 2014b). However, as the interventions were only implemented in the school building but not during class, teachers will need additional interventions in order to deal with inattention and off-task behavior of children with ADHD during the lessons. Interventions to improve sustained attention, on-task behavior or ADHD symptoms in the classroom include self-monitoring strategies of attention and performance (Harris, Friedlander, Saddler, Frizzelle, & Graham, 2005) and self-regulatory strategies like implementation intentions (Guderjahn et al., 2013). For instance, in a study, children selected a school-related goal that they wanted to achieve and subsequently choose an implementation intention to reach the desired goal (e.g., “If a classmate talks to me, then I will focus more intently on the lesson”). In line with the results of the current study, children most often chose goals to improve their attention and on-task behavior during class (Guderjahn et al., 2013), indicating the importance of sustained attention in ADHD. However, the effectiveness of self-regulatory strategies to improve ADHD symptoms during class is still less clear (Hodgson, Hutchinson, & Denson, 2014) and future studies need to investigate under which conditions and for which children these interventions work best.
However, whereas these trainings and interventions were specifically designed to improve sustained attention, the results of the current thesis suggest another type of intervention as indirect effects have been observed for sustained attention and behavioral inhibition through risky decision-making. The presence of indirect effects is in line with the theoretical assumption that associations between two constructs are maximal when both constructs correspond in nomothetic span (Wittmann & Klumb, 2006). If this principle is transferred to the implementation of interventions, it follows that interventions tapping on specific deficits, such as sustained attention, might be efficient in the treatment of specific deficits in ADHD, but not in reducing overall ADHD symptoms. Instead, broader unspecific interventions could have stronger effects by influencing a larger number of higher cognitive functions as for instance risky decision-making. Indeed, a recent intervention program called TEAMS (Halperin et al., 2013) aimed to improve inhibition, attention, and motor skills through games and physical exercises that adapt to the children’s skill level and are fun to
perform. In addition, TEAMS acknowledges the importance of the social context by being administered both within small groups of peers and within families (Halperin et al., 2013). Preliminary results indicated that TEAMS effectively reduced ADHD symptoms according to parent and teacher ratings and the effects persisted for three months (Halperin et al., 2013).
Taken together, results from the current thesis argue for two kinds of intervention programs in ADHD. First, specific interventions (e.g., attention trainings or neurofeedback) to reduce deficits in sustained attention and off-task behavior might treat a core deficit in ADHD. Second, more general interventions might help to reduce ADHD symptoms by capitalizing on indirect effects on ADHD, as several basal functions and higher cognitive functions might be affected simultaneously.