Poster #: 23
Topic: Clinical applications (incl. consciousness)
Thursday, Sep 10, 2015
Effect of methylphenidate in adult attention-deficit/hyperactivity disorder as reflected by MMN
1Psychiatry, Fukushima Medical University, Fukushima, Japan
2Fukushima Medical University, Fukushima, Japan
A number of studies have recently reported that patients with ADHD fail to exhibit alleviation of symptoms such as inattentiveness and impulsiveness even after adulthood. One effective pharmacotherapy for ADHD is methylphenidate (MPD). However, judging the curative effect uses observation and a check list of changes in symptoms. An objective method for measuring effects is therefore necessary. Mismatch Negativity (MMN) is automatically elicited by occasional deviations within a sequence of homogeneous (standard) sounds. Some MMN studies have been performed for infant ADHD. Sawada et al. (2010) reported improvement of the MMN amplitude in infant ADHD with MPD medication, whereas Winsberg et al. (1993) found no such change. No studies of MMN with adult ADHD have reported an effect of osmotic-release MPD. We therefore examined cognitive function change with MPD in adult ADHD by measuring MMN. Methods: Sixteen individuals with adult ADHD (nine men; mean age, 37 years) were recruited from outpatients treated at Fukushima Medical University according to the criteria of the DSM-IV and confirmed using Conners’ Adult ADHD Diagnostic Interview for DSM-IV. All stimuli were 1000Hz in frequency. Standard (80%) stimuli was 100 msec, and deviant stimuli (20%) was 50 msec in duration. We measured and compared MMN before and after treatment. Results: No significant differences in peak amplitude or peak latency of MMN were seen. Discussion: This result was similar to that of Winsberg for infant ADHD, but unlike the results of Sawada. The fact that this modality differed from preceding studies using frequency MMN needs consideration.