Patients taking medication for ADHD should immediately report any suicidal thoughts to their doctor even after ADHD therapy has been stopped.

In 2005, an increased risk of suicide ideation and suicidal behavior was identified with the use of the drug Strattera but emerging information suggests the risk may apply to all other ADHD drugs.
The benefits of the drugs in managing ADHD continue to outweigh their risks, but Health Canada emphasizes that mood swings, behaviors, thoughts and emotions need to be monitored. Patients taking an ADHD medication should immediately report any suicidal thoughts to their doctor even after ADHD therapy has been stopped.
Source-Medindia