If some of your boomer clients seem … off (or really hungry) in your next client review, there's a reason. Baby boomers are increasing their use of illicit drugs as they age. According to the Substance Abuse and Mental Health Services Administration (SAMHSA), those aged 50 to 59 reporting use of illicit drugs within the past year has nearly doubled from 5.1 percent in 2002 to 9.4 percent in 2007. Rates among all other age groups are staying the same or decreasing.