I heard that, and thought, as I often do, maybe we are wrong and need to check the stats. After all, the fact that one study is demonstrably crap is absence of evidence, not evidence of absence.
So I had a quick browse through PubMed, and the stats are bad in both senses - studies are hard to do, because of the woolly definition of trans, but also they nearly all show a higher, sometimes much higher, rate of suicidal ideation than the norm.
Mostly, the studies start by talking about LGBT people, then somehow slide into treating this as 'trans-only' rates, which is bloody annoying.
From BMC Psychiatry:
'Little research has compared prevalence of suicidal behavior in trans-gender people to other population groups. One study using a nonclinical sample of over 40,000 largely U.S. volunteers who completed an internet survey found 73 individuals who identified themselves as transgender. This group's responses related to suicidal behavior were compared to those reported by six other groups: heterosexual males and females, homosexual males and females, and males and females who matched the transgender individuals on nationality, age, sexual orientation, relationship status, and population size of the area in which they resided.
Transgender respondents had a higher rate of reported suicide attempts than any group except homosexual females.'
'Suicide attempt rates ranging from 19 to 25% have also been reported among clinical samples of transgender individuals seeking surgical gender reassignment (Dixen, Maddever, van Maasdam, & Edwards, 1984). More recent data from nonrandom surveys of self-identified transgender people found that up to one third of respondents report making one or more lifetime suicide attempts'
It would be enough to worry me as a parent, but it's not 50%. And I've yet to find much info broken down into how the outcomes improve/worsen after social or physical transition.