Ask supervisors in your department if they know of any intervention development courses or seminars. Contact the people at human resources and let them know you are interested in any in-house training in that area.
Do a review of the intervention development literature. Take extensive notes and include all citation information, including specific page numbers so you can review the material as required.
Approach the social work department at your local college or university and indicate that you are interested in doing an independent study on intervention development. Work with a supervisor to write a course outline of what you will study, the resources you will use, the assignments you will do and how the study will be assessed.
Contact the local community clinic, needle exchange program and emergency room to ask if they know of any available training. If they don't, inquire if they know any agency that does.
Phone your local community college and university to inquire if they are offering any courses on intervention development. Indicate your interest in the topic and ask to be notified if anyone offers a course on that topic.
Do some volunteer work. Find out which local agencies work with drug users--such as the Salvation Army--and arrange to do some field work or out-calls with them. This sort of practical experience will help you make an informed decision about the sort of training you require.