Objectives: In 1967, despite escalating international hostility towards psychosurgery, a program of amygdaloid neurosurgery for the reduction of aggressive and self-harming behaviour commenced in Sydney. In this paper, the second of two articles on the Amygdaloid Neurosurgery Project (ANP), we analyse the relative contributions of seven nominated societal, ethical and other factors to the genesis and demise of the ANP, and consider implications of the history of the ANP for the future of neurosurgery for psychiatric disorders (NPD) in New South Wales (NSW) and elsewhere.
Conclusions: Leadership and the availability of resources were crucial factors in the genesis of the project. Its scientific foundations were doubtful in 1967, and remain so in 2009. Ethical issues became the focus of hostile media and Government attention in 1977 and precipitated the project's demise. Lessons derived from an historical analysis of the ANP should assist the medical profession develop appropriate approaches to recent advances in NPD, including deep brain stimulation, new ablative procedures and stem cell implantation.