My friends son has a dx of DAMP....this is what she has told me....so I will pass it on.
DAMP = Deficits in Attention, Motor Control and Perception.
The reason you will not find much information about DAMP is because the literature and information is most exclusively written in Danish or Swedish as DAMP has been a diagnosis only used in Nordic countries until recently.
SAMP and ADHD are almost the same thing, the difference is DAMP requires that a person has a Motor Control and Perception difficulty, (Dyspraxia - also called Motor perceptual Problem or DCD - Develpomental Co-ordination Delay), so it is a narrower definition of ADHD.
When problems are severe and all the diagnostic features are present the critria for Hyperkinetic Disorder may be met. They are restlesness, fidgety and over active, continual chatter,interupts people when they are talking, easily distracted and dont finish things,inattentive and can not concentrate on tasks, impulsive, difficulty waiting turns, etc etc...
Basically ADD, DAMP and Hyperkinetic Disorder are all subtypes of ADHD.
Because of the massive incline in people gaining dx of ADHD and the publicity about it in the media, Peads are now dxing DAMP to try and offset the number of children with an ADHD dx.
Hope this helps.