I am glad that my hon. Friend made that intervention. I had not intended to deal with that issue, but I think that he is right. Leaving aside the criminal justice issues, we should not underestimate the public health issues associated with drug use, and especially with the prolonged use of cannabis by teenagers. Some of the latest research by the Medical Research Council is pointing towards the existence of a common genetic mutation, occurring in about a quarter of the population, that could give rise to a substantial increase in the likelihood of psychotic episodes and schizophrenia as a result of prolonged cannabis use during the teenage years. That evidence should not be just put to one side—it should inform directly the calculation of potential harm that is supposed to underlie the advice given by the Advisory Council on the Misuse of Drugs. Sir Michael Rawlings, who leads that council and is chairman of the National Institute for Health and Clinical Excellence, ought to be rigorous in his examination of the medical evidence underlying those issues. If that has not been true up to now, I hope that it will be in future.