The riskiest years for addiction begin when someone is as young as 10 and stretch straight through to the age of 24. After that a person is pretty much clear of the danger or sheer out of luck. But does it have to be that way? In The Addiction Inoculation (Harper), Jessica Lahey comes up with countermeasures to just about every situation that can befall a parent — and their child. She also provides a dose of prevention that’s worth at least a kilo of any so-called cure.