Aside from probable drug tolerance,what kind of adverse effect could taking ritalin (methylphenidate) cause for healthy adults?

Ritalin (methylphenidate) side effects: Ritalin, (methylphenidate) a stimulant medication, is most commonly prescribed to treat ADD/HD in children and adults, but can also be used in other treatments. Besides tolerance, possible side effects may include decreased appetite, GI upset, headache, anxiety, irritable mood, insomnia or elevated BP. You should always discuss risks/benefits & of SEs of any proposed tx with ur doc b4 starting any new med.

Many serious ones: Ritalin (methylphenidate) commonly causes many serious side effects including addiction, anxiety, agitation, paranoia, insomnia, headaches. palpitations, high blood pressure, seizures, liver inflammation, sweating, dizziness and nausea. See http://ritalinsideeffects.net/ "Healthy adults" should NEVER take Ritalin (methylphenidate) if they want to stay healthy.