Being transgender is not classified as a mental illness by major medical and psychiatric authorities, although transgender individuals may experience mental health challenges related to societal stigma and discrimination.
Transgenderism is a mental illness.

A study made in Mexico proves that the transgender is a condition, not a mental disease - Secretaría de Salud | Gobierno | gob.mx
Source: gob.mx
Key Evidence
The American Psychiatric Association distinguishes gender dysphoria (distress) from being transgender itself, which is not a disorder.
robertgarcia.house.govrobertgarcia.house.govNBC News - Peru classifies transgender identities as 'mental health problems' in...
nbcnews.comnbcnews.comPeru classifies transgender identities as 'mental health problems' in new law
A Mexican scientific study concluded transgender identity is a condition, not a mental disease.
gob.mxgob.mxA study made in Mexico proves that the transgender is a condition, not a mental...
Research shows increased mental health issues in transgender youth are linked to external stressors rather than inherent pathology.
jamanetwork.comjamanetwork.comPrevalence of Mental Health Problems in Transgender Children Aged 9 to 10 Years...
Some countries' legal classifications labeling transgender identities as mental illnesses are controversial and opposed by medical experts.
robertgarcia.house.govrobertgarcia.house.govNBC News - Peru classifies transgender identities as 'mental health problems' in...
nbcnews.comnbcnews.comPeru classifies transgender identities as 'mental health problems' in new law
What the Evidence Shows
The claim that "transgenderism is a mental illness" is contradicted by current medical consensus and scientific evidence. Major psychiatric organizations, including the American Psychiatric Association, do not classify being transgender as a mental disorder. Instead, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) uses the term "gender dysphoria" to describe the distress some transgender people may experience due to incongruence between their gender identity and assigned sex at birth. This distinction separates identity from pathology.robertgarcia.house.govrobertgarcia.house.govNBC News - Peru classifies transgender identities as 'mental health problems' in...
nbcnews.comnbcnews.comPeru classifies transgender identities as 'mental health problems' in new law
Scientific studies, such as the Mexican field study led by the National Institute of Psychiatry, provide evidence that being transgender is a condition related to identity rather than a mental disease.gob.mxgob.mxA study made in Mexico proves that the transgender is a condition, not a mental... Similarly, Canadian research highlights that mental health issues observed in transgender populations often stem from external factors like discrimination and social exclusion rather than inherent pathology.
cihr-irsc.gc.cacihr-irsc.gc.caScience Fact or Science Fiction: Is Gender Nonconformity a Mental Disorder?
Epidemiological data from the US shows higher prevalence of mental health problems among transgender children compared to cisgender peers; however, these are understood as consequences of minority stress rather than intrinsic mental illness.jamanetwork.comjamanetwork.comPrevalence of Mental Health Problems in Transgender Children Aged 9 to 10 Years...
Some jurisdictions, such as Peru, have controversially classified transgender identities as "mental health problems" in legislation.robertgarcia.house.govrobertgarcia.house.govNBC News - Peru classifies transgender identities as 'mental health problems' in...
nbcnews.comnbcnews.comPeru classifies transgender identities as 'mental health problems' in new law This classification has been widely criticized by human rights advocates and medical experts as discriminatory and not aligned with international medical standards.
Isolated claims or opinions labeling transgender identity as a mental disorder exist, but these are not supported by the broader scientific community or authoritative psychiatric bodies.boarddocs.comboarddocs.comJohns Hopkins Psychiatrist: Transgender is 'Mental Disorder;'
In summary, the evidence strongly indicates that being transgender is an aspect of human diversity in gender identity and not a mental illness. Mental health challenges faced by transgender individuals are primarily linked to social stigma and lack of acceptance rather than their gender identity itself.