Gender dysphoria, the mento-emotional component of being trans, involves feelings of low self-esteem, a distorted sense of self, depression, anxiety & obsessionalism.  And it is clearly hormone sensitive. 

 Putting the genie back in the bottle

Feminizing hormones have a powerful impact on those brain modules that are involved with depression, anxiety & OCD.  So yes indeed, feminizing hormone therapy can mute the symptoms of gender dysphoria, but only if the flow of testosterone is kept consistently under wraps & only when hormone delivery is both strong enough to be effective & is delivered in such a steady flow as to prevent testosterone escape.