Hello,
Thanks for posting your query.
Vyvanse has active ingredients of lisdexamfetamine dimesylate and
Celexa has active ingredients of citalopram hydrobromide.
Both medications have both short term as well as long term sideffects ( after many years )(no definite guidelines however).
These may be
1     Short-term Memory Loss     
2     Exhaustion, Fatigue, Lethargy.
3. Metabolic Syndrome     
5     Self Mutilation     
6 Stress And Anxiety     
7     Hypersensitivity     
8     Dissociation     
9 Brain development problems - ADD and ADHD medication usage on a developing brain is not known at this time, however there is a concern on the long term effects and their interference with normal brain development.
In addition it may increase chances of abuse and psychotic illnesses in future .
So remember that ADHD medications are very useful in the treatment of "Attention Deficit Disorders" however over time the medications must be carefully monitored to make sure that not only does the child still need them but to make sure they are not producing any ill effects. ADHD medications may make it easier a child with attention deficit disorders to concentrate, follow through on tasks and control impulses however it is not a cure. Even if a child is on medications they will still experience some difficulties such as emotional problems, absent mindedness and social difficulties.

Hence the answer to your query cannot be termed in quantity as there are no fixed sidefects or the duration for the safety but your child's doctor will always weigh the risk benefit ratio for individual before modifying or stopping the therapy.
Hope I have answered your query.
I'll be available for any follow up queries.
Regards

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