In 1965 the British government was forced to admit that the country had an escalating heroin problem, with the supply coming mainly from prescribing by private practitioners. Within the official responses to what was seen at that time as a very worrying public health situation was the decision to fund the setting-up of the Addiction Research Unit (ARU) at the Institute of Psychiatry, London. The US National Institute of Mental Health (NIMH) generously sponsored a study tour for the nominated director of the ARU shortly before the opening of the British research centre. Extensive contemporaneous diary notes of a visit included contact with administrators, researchers, clinicians, parish priests, narcotic agents and addicts themselves. From a mass of often conflicting advice, some insights could be derived. In particular, these included the need for an awareness of any country's way of dealing with drug problems as a dynamic, multi-factorial total system—a holistic ‘national response’. A further conclusion was to see policy itself as a complex subject for analysis: drug policy should be as much an issue for research as drug taking. Besides these broad conclusions, the experience provided many specific leads to development of a British addiction research programme, and fostered professional friendships of immeasurable worth.