I don't think it's just stigma that is problem about diagnosis.

I seen far too many people cling to the idea that their brain is broken and they will never life full life (with "but it's not my fault!" as a tagline).

What surprised me, a lof of people who went through traumas and abuse kinda refuse to acknowledge this could affect them, because their bipolar/depression is "medical illness just like diabetus" and it's about chemical imbalances and chemical imbalances only. It makes me feel these people are just seeing themselves worthless and broken in other way... but maybe to such cathegory, labels and medical lingo tied to it, can hold back recovery if other aspects are no acknowledged.