I learned that adhd could be misdiagnosed as bipolar and vis versa. is that true?

YES: A skilled health care professional is necessary to differentiate adhd, bipolar disorder & other psychiatric, medical, neurological conditions that may appear like each other or overlap in symptoms & impact an individual. These conditions may also occur at the same time in an individual & a careful diagnostic differentiation & treatment plan is necessary for proper management.

Yes: there is some symptom overlap. That is why it is important not the jump the gun and try to make a diagnosis without a thorough evaluation. Comprehensive psychiatric / psychological evaluation (often over time) can usually tease these conditions apart or they may be co-existing.