Vincent's book Self-Made Man retells an eighteen-month experiment in which she disguised herself as a man. This follows in the tradition of undercover journalism such as Black Like Me. Vincent talked about the experience in HARDtalk extra on BBC on April 21, 2006 and described her experiences in male-male and male-female relationships. She joined an all-male bowling club, joined a men's therapy group, went to strip clubs and visited Catholic monks in a cloister. She dated women and describes how inferior she felt. Vincent writes about how the only time she has ever been considered excessively feminine was during her stint as a man: her alter ego, Ned, was assumed to be gay on several occasions, and features which in her as a woman had been seen as “butch” became oddly effeminate when seen in a man. (She is a lesbian.) Vincent asserts that, since the experiment, she has never been more glad to be female.

Her most recent book is Voluntary Madness, about her experiences as an inpatient in three different mental hospitals. Suffering from depression after her eighteen months living disguised as a man, Vincent felt she was a danger to herself. On the advice of her psychologist she committed herself to a mental institution. She spent time in three different institutions — one urban, public and ill-funded; one small-town; and one private and expensive. She found some parts of the mental health care system beset by arrogant doctors and over-reliance on drugs as therapy, while others addressed merely the problem instead of its symptoms.

Although Vincent did not gain access to the hospital by means of deception, her expose can be compared to Ten Days in a Mad-House by undercover reporter Nellie Bly, written more than a century previously (1887). The Rosenhan experiment in the 1970s also provides a comparison of life inside several mental hospitals.