Prejudice is when someone has a negatively biased outlook towards a certain group of people, and a negative attitude towards them.
Discrimination is when those feelings are acted upon.
These issues may impact someone with a mental health condition by making their symptoms worse, making them become discouraged or lose hope, and by creating a negative environment in which they cannot be accepted, cope, or heal.
Also, it may affect those born with permanent mental health needs by creating a toxic environment in which they cannot comprehend why they are being treated the way they are, causing them to either shun themselves from society, or lash out towards it.