[1] He studied psychology, sociology and education at Victoria University of Wellington, graduating Bachelor of Arts with honours, before working as a government policy advisor for seven years.
[5][6][7][8] A self-described pro-choice atheist and rationalist,[9][10] Fergusson undertook his first investigation with the expectation that his cohort data would prove that the apparent link between abortion and mental health problems would be explained by pre-existing factors.
[11] The study found abortion was linked to higher rates of depression, anxiety, drug and alcohol abuse, and suicidal behaviours.
"[9] Fergusson also reported experiencing difficulties getting his study published since the results contradicted the prevailing view that abortion does not have mental health consequences.
[16] The same year, he was awarded the Christchurch School of Medicine and Health Sciences gold medal for research excellence.
[18] Fergusson was an Honorary Fellow of the New Zealand Psychological Society and the Royal Australasian College of Physicians.