Teen smoking rates in the United States last year were the lowest they have ever been in more than two decades, according to a recent federal report. However, not everything about adolescent behavior as improved, nor is this "good news" without flaw. 

Cigarette use among minors in the US had dropped to just 15.7 percent as of December 2013, according to this week's Morbidity and Mortality Weekly Report (MMWR) titled "Youth Risk Behavior Surveillance - US 2013."

According to the report, smoking rates were much higher in 2011 (at 18.1 percent), and in 1997 rates peaked with more than 36 percent of all teens lighting up before they turned 18.

This then is fantastic news for the CDC, who had hoped to reduce adolescent smoking rates to 16 percent by 2020.

However, even in light of this good news, the report details that a number of risky behaviors among youths are still on the rise. Excessive alcohol consumption, unhealthy inactivity, and texting while driving have all seen small increases. Texting while driving is proving the most worrisome, according to the authors of the report, with more than 41 percent of all teens reporting having texted while they drove at least once in a 30 day period in 2013.

What's more, the CDC report does not account for an important factor that could heavily affect their one cause for celebration. Electronic cigarettes which, until just recently, were available to minors, could have simply veiled teen smoking rates, as the devices are not classified as tobacco cigarettes.

Teens could have simply turned from traditional cigarettes to the more readily available electronic product, which often come with attractively colored devices and flavors.

A study published in JAMA Pediatrics earlier this year found that using electronic cigarettes actually encouraged the development of a nicotine addiction among teens, and could eventually lead to a standard cigarette habit by the time they turn 18.

Since then, legislation has banned the sale of these products to minors, but CDC investigators have not overlooked the potential for these devices to influence their seemingly encouraging data.

The MMWR was released by the CDC on June 10 for the week of June 13.