Methylphenidate is a powerful drug with many potential side effects and contraindications. For this reason it should only be obtained on prescription from either a paediatrician or psychiatrist, or from a GP on the advice / recommendation of a psychiatrist.
According to NICE (2000),
“On the basis of evidence from experts, the Committee concluded that [methylphenidate] treatment should only be initiated by an appropriately qualified healthcare professional with expertise in ADHD and should be based on a comprehensive assessment and diagnosis.”