Legal assisted suicide could add to the disadvantages already faced by people with mental illness, leading psychiatrists have warned.

Editor of the British Journal of Psychiatry, Professor Kamaldeep Bhui, and Sydney University's Psychiatry Chair, Professor Gin Singh Malhi, have raised concerns about the implications of Baroness Meacher's Assisted Dying Bill for psychiastrists and mental healthcare.

"People with mental illness already face multiple disadvantages, premature mortality, poor physical healthcare and end-of-life care, and may further be disadvantaged by legislation that is blind to pre-existing inequalities," they warned in the journal.

Citing evidence from countries where assisted suicide is already legal, they argued that "patients may be coerced when making their decision not least by family members and friends who are likely to have conflicts of interest".

"At the heart of the many debates is the key question of who should ultimately decide; and if it is decided to assist in death, then how should this be enacted. Leaving it solely to doctors has proven to be problematic, with some patients taking matters into their own hands if their wishes are not supported.

"At the same time, it seems inappropriate to direct doctors to assist, especially if it runs against their own ethical, professional, spiritual and personal values," the professors argued.

They also warned about the greater powers doctors would have in delivering euthanasia: "The powers invested in the medical profession are also a cause for some concern in light of past atrocities enacted because of both personal and societal prejudices – in which doctors have been seen to collude with dubious political goals, including scientific racism and eugenics."

They gave as an example of abuse by doctors the Tuskegee experiments in the USA that involved withholding the diagnosis and treatment of black males infected with syphilis, and "spurious claims of racial inferiority that were investigated by scientists worldwide, in addition to the abuses that occurred at the time of the Holocaust in the Second World War under the guise of research".

"It is therefore understandable that professionals and the public are sensitive to the potential misuse of medical authority," they wrote.

Baroness Meacher's Bill is at Committee Stage in the House of Lords but anti-euthanasia campaigners have expressed confidence that it will run out of parliamentary time because it does not have government support.

Lord Forsyth's bid to legalise assisted suicide through an amendment to the Health and Care Bill this week failed in the Lords.