From this blog
Gender Identity Disorder is very much a mental illness. It causes people to:
— hate their own bodies up to and including a strong urge to cut off perfectly normal, perfectly healthy body parts, take dangerous hormones, etc.;
— be virulently jealous of people who have the body-type they wish they had or think they “ought” to have;
— be completely, self-indulgently, vociferously irrational about the simple facts of reproductive biology, unlike 99.8% of the rest of adult human beings (e.g. demanding that others agree that their penis is “really female” and that their male body is “really a lesbian’s body”, etc.);
— based on my observations, GID also causes people to engage in histrionic manipulation, to engage in obsessive behaviors (e.g. stalking people who reject them sexually, relentlessly following people on-line that they “hate”, spending thousands of hours over a period of decades endlessly obsessing over “gender” presentation) and to exhibit extremely poor impulse control, for example, lashing out with virulent death wishes or threatening/attempting suicide when socially thwarted, and entering into dangerous sex-work, drug abuse, drinking binges, homelessness, etc. rather than successfully adjusting their life-style to fit in with the basic parameters of the working world — a world that millions of (for example) lesbians, bisexuals and gay men manage to negotiate successfully despite our differences from the expected social “norm”.
GID also appears to present with the co-morbidity of clinical depression in a high percentage of cases.