Self concept, action control and ADHD symptoms under methylphenidate treatment in adults with ADHD.

INTRODUCTION: Self-efficacy of adults with ADHD might be changed unfavourably under methylphenidate treatment. Therefore, we sought to investigate the initial situation and changes under this medication, regarding features related to self-efficacy (self concept, locus of control and action control). METHODS: 3 self-rating scales (FSKN, IPC, and HAKEMP-90/ACS-90) were applied to 24 adults with ADHD combined type, before and after 5 months of methylphenidate treatment. RESULTS: No negative changes with respect to ADHD symptoms or any questionnaire were found under medication. In fact, both ADHD symptom domains, 5 out of 10 self concept subscale scores, and all 3 action control subscale scores changed favourably. Regression analysis revealed that only facets of self concept, but not of locus of control or of action control, predicted the patients' response to stimulant medication (i.e., a reduction of ADHD symptoms). DISCUSSION: Positive changes of self-concept and action control features under methylphenidate treatment in this study may encourage therapists to treat adults with ADHD with stimulants, thus not being at risk to decrease their patients' self-efficacy. In combined pharmacological/psychotherapeutic approaches, self-concept scales could be used to predict treatment outcome, and in order to monitor interactions between ADHD symptom reduction and self concept.

[llocalization of grouping effect in overlapping tasks]. / Die Lokalisierung des Gruppierungseffektes bei überlappenden Aufgaben.

In certain kinds of overlapping tasks subjects have to respond to two stimuli (S1 and S2), presented in close succession with variable onset asynchrony (SOA), carrying out two different responses (R1 and R2). When responding to S1 is given priority over S2 processing, reaction time (RT) to the first stimulus is unaffected by SOA. However, sometimes subjects adopt, either spontaneously or because of instruction, a different processing strategy called grouping. In this case R1 is postponed until R2 has been determined too. The present study addresses the localization of the postponed processing stage by means of the lateralized readiness potential (LRP). One group of subjects was instructed to group responses and a second group was to give priority to S1 processing. The adherence to instructions was verified by subjects' reaction times. In case of grouping the interval between LRP onset and overt reaction increased proportionally to the postponement caused by SOA. In contrast, the interval between stimulus and LRP onset was unaffected by SOA. These findings speak against assumptions that grouping causes response activation postponement; rather, the corresponding reaction is already selected and activated prior to postponement.