From the ADHD institute, redacted to remove adolescent specific information, referencing the DSM-V(Diagnostic and Statistical Manual of Mental Disorders, fifth edition):
Overview of the DSM-5[SUP]TM[/SUP] medical classification system for ADHD
- A persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development:
- For adults, five or more symptoms are required (Table)
- Several symptoms present prior to age 12 years
- Several symptoms present in two or more settings (e.g. at home, school or work; with friends or relatives; in other activities)
- Clear evidence that the symptoms interfere with the quality of, social, academic or occupational functioning.
- Symptoms do not occur exclusively during the course of schizophrenia or another psychotic disorder, and are not better explained by another mental disorder
DSM-5[SUP]TM[/SUP] diagnostic criteria for ADHD
[TABLE="width: 980"]
[TR]
[TD]
Symptoms of inattention[/TD]
[TD="width: 189"]
Symptoms of hyperactivity and impulsivity[/TD]
[/TR]
[TR]
[TD="width: 183"]Often fails to give close attention to detail or makes mistakes[/TD]
[TD="width: 189"]Often fidgets with or taps hands and feet, or squirms in seat[/TD]
[/TR]
[TR]
[TD="width: 183"]Often has difficulty sustaining attention in tasks or activities[/TD]
[TD="width: 189"]Often leaves seat in situations when remaining seated is expected[/TD]
[/TR]
[TR]
[TD="width: 183"]Often does not seem to listen when spoken to directly[/TD]
[TD="width: 189"]Often runs and climbs in situations where it is inappropriate (in adolescents or adults, may be limited to feeling restless)[/TD]
[/TR]
[TR]
[TD="width: 183"]Often does not follow through on instructions and fails to finish schoolwork or workplace duties[/TD]
[TD="width: 189"]Often unable to play or engage in leisure activities quietly[/TD]
[/TR]
[TR]
[TD="width: 183"]Often has difficulty organising tasks and activities[/TD]
[TD="width: 189"]Is often ‘on the go’, acting as if ‘driven by a motor’[/TD]
[/TR]
[TR]
[TD="width: 183"]Often avoids, dislikes or is reluctant to engage in tasks that require sustained mental effort[/TD]
[TD="width: 189"]Often talks excessively[/TD]
[/TR]
[TR]
[TD="width: 183"]Often loses things necessary for tasks or activities[/TD]
[TD="width: 189"]Often blurts out answers before a question has been completed[/TD]
[/TR]
[TR]
[TD="width: 183"]Is easily distracted by extraneous stimuli[/TD]
[TD="width: 189"]Often has difficulty waiting their turn[/TD]
[/TR]
[TR]
[TD="width: 183"]Is often forgetful in daily activities[/TD]
[TD="width: 189"]Often interrupts or intrudes on others[/TD]
[/TR]
[/TABLE]
You shouldn't have a problem getting a prescription for your choice of Methylphenidate(ritalin/concerta), Adderall(mixed (d/l-amphetamine salts), or Vyvanse(prodrug of dextroamphetamine). As long as you present with at least 5 of the above symptoms, don't have any blood pressure/heart issues(eg, arent taking meds for high bp or beta blockers for heart function), and aren't being treated for a number of psychotic/manic disorders/anxiety. The long term safety of amphetamine(not methamphetamine, which is neurotoxic at any dosage) has been pretty well established at dosages appropriate for ADHD/ADD treatment, which is well below the recreational dosage.
Negged. 
