ADHD

Studies conducted at University of Nottingham on mental health recently published

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"The present study therefore examined the effects of MP on learning the association between a conditioned stimulus (CS, in this case, noise) and an unconditioned stimulus (UCS, in this case, footshock) in an aversive variant of a trace conditioning procedure. Learning was measured off-the-basetine as conditioned suppression of drinking (both Latencies to drink, expressed as suppression ratios, and the amount drunk, expressed as the number of ticks, in the presence of the CS). In addition to the measures of discrete cue conditioning, MP effects on contextual conditioning were measured as suppression to apparatus cues and an experimental background stimulus. MP was administered at I or 5 mg/kg prior to conditioning sessions. As attention deficit hyperactivity disorder (ADHD) has been characterized as involving a 'wide attentional window' (e.g. Shalev and Tsal, 2003), it was predicted that MP, as the treatment of choice for ADHD, should increase selectivity (narrowing the attentional window). This outcome would show as reduced Levels of conditioning (compared to control rats) to Less informative trace and contextual cues present during conditioning. Contrary to prediction, both I and 5 mg/kg MP increased learning about all the available stimuli, including the less informative trace CS and the background stimulus," wrote R.R. Horsley and colleagues, University of Nottingham.

The researchers concluded: "These findings are consistent with reduced rather than increased selectivity in learning (because of increased rather than decreased conditioning to weak cues) under MP."

Horsley and colleagues published their study in the Journal of Psychopharmacology (Methylphenidate can reduce selectivity in associative learning an aversive trace conditioning task. Journal of Psychopharmacology, 2007;21(5):492-500).

For more information, contact H.J. Cassaday, University of Nottingham, School Psychology, Institute Neuroscience, University of Pk, Nottingham NG7 2RD, UK.

Publisher contact information for the Journal of Psychopharmacology is: Sage Publications Ltd., 1 Olivers Yard, 55 City Road, London EC1Y 1SP, England.

Keywords: United Kingdom, Nottingham, Mental Health, University of Nottingham.

This article was prepared by Mental Health Weekly Digest editors from staff and other reports. Copyright 2007, Mental Health Weekly Digest via NewsRx.com.