I will look--I've seen it in a couple written forms (maybe Miraca Gross) but definitely heard talks about it: SENG Arlene DeVries said not only is their suicide rate higher, but they don't make mistakes (so they actually succeed more than attempt). We had a gifted HS student recently succeed in my town. Very sad. No one knew there was trouble.

Here's something from M. Gross: "The common perception of the extremely gifted as eager, academically successful young people who display high levels of task commitment has been refuted by research. This research demonstrates that many highly gifted children underachieve seriously in the regular classroom and that by the end of elementary school, many have almost completely lost the motivation to excel (Pringle, 1970; Painter, 1976; Whitmore, 1980; Gross, 1993).

The majority of the extremely gifted young people in my study state frankly that for substantial periods in their school careers they have deliberately concealed their abilities or significantly moderate their scholastic achievement in an attempt to reduce their classmates' and teachers' resentment of them. In almost every case, the parents of children retained in the regular classroom with age peers report that the drive to achieve, the delight in intellectual exploration, and the joyful seeking after new knowledge, which characterized their children in the early years, has seriously diminished or disappeared completely. These children display disturbingly low levels of motivation and social self-esteem. They are also more likely to report social rejection by their classmates and state that they frequently underachieve in attempts to gain acceptance by age peers and teachers. Unfortunately, rather than investigating the cause of this, the schools attended by these children have tended to view their decreased motivation, with the attendant drop in academic attainment, as indicators that the child has "leveled out" and is no longer gifted (Gross, 1993).
Gross's Exceptionally Gifted Childrenhas a whole chapter on self-esteem, underachievement,

I am a witness to underachievement in underchallenged HG/PG middle school students. We have 7 kids in my son's class with IQ>145. One is failing, two others crashing fast. 50% underachievement--of course the ones who are failing are all boys.