The cognitive impairment tends to come in low-self esteem, poor self-image, depression, anxiety, and a high risk of suicide. Transitioning has far better results than what many psychotropic and other medications, and these cognitive impairments generally improve.
With bipolar disorder they experience what they often describe as an "emotional roller coaster" of highs/manias and lows/depression. These moods can last from just a few moments to over a month. They struggle to function because they are either high off mania which can lead to impulsive, high risk, and destructive behavior or they lack the motivation to do anything, often including live. They too are of a high risk suicide group. Cognitive, behavioral, and mood-management works wonders, as does medication. The treatment, really at its very essence, is no different than a sex/gender change as they both require changes in living habits, changes in situations, and learning to work your way through such emotional difficulties, and coming out better than you were, and always working towards improvement. When it comes to gender dysphoria, no other treatment has ever produced such results, but, rather, much like we see in the so-called "conversion 'therapy,'" clients tend to worsen in their condition.
Now, you can try to claim science is on your side, you are saying "bipolarism," I have access to journal databases and a degree. If things go well, I'll even be starting internships and supervised clinical hours next spring semester. Not to gloat, but when you want to say "science is driven by facts," yes, it very much is; Those facts, gathered across pretty much every field related to neuropsychology, biology, and every discipline of the social sciences, do not agree with you.