Atomoxetine may improve methylphenidates' efficacy in treatment of ADHD?

Methylphenidate, a psychostimulant, is first choice treatment for Attention Deficit Hyperactivity Disorder (ADHD)(Dopfner et al. 2002). Unfortunately, it has many adverse side effects, especially depression and appetite loss, which limits its dosage. There are only a few studies investigating the effect of a combination of Methylphenidate and other psychoactive substances, especially antidepressants (Pataki et al. 1993). Recently, the noradrenaline reuptake inhibitor Atomoxetine has been developed also for this disorder (Purper-Ouakil et al. 2005). Recent literature reports poorer efficacy of Atomoxetine, compared to that of Methlyphenidate (PurperOuakil et al. 2005). Atomoxetine`s antidepressant effect leads to the hypothesis, that it may help to 1. reduce the dosage of Methylphenidate and 2. reduce its above mentioned adverse side effects. For that reason we assume that these problems can be resolved using Atomoxetine additionally to Methylphenidate. We proved this hypothesis on a 11 year old male patient diagnosed as ADHD according to the practice parameters of the American Academy of Child and Adolescence psychiatry, including EEG, blood sample, magnetic resonance tomography, psychological tests (WISC: IQ=97), and Conner Scales, where Methylphenidate (20 mg daily), given for 2 months, led to depressed mood and appetite loss. Reducing its dosage to 10 mg worsened ADHD symptomatology while improving the depressed mood. After 1 month, a switch to Atomoxetine up to 40 mg did not treat the disattention sufficiently. Atomoxetine was given for 2 months. Under additive administration of Methylphenidate (10mg daily) for 3 months, the mood remained stable, while ADHD symptomatology improved impressively. The reported case mainly shows that the combination between atomoxetine and methylphenidate helped reducing the dose of methylphenidate and thus, probably the side effects while showing beneficial clinical effects. Further systematic research should be done to investigate this observation.