Three Denver area teenage girls—one of Somali descent and two of Sudanese descent—were intercepted in Germany recently, reportedly on their way to Turkey, in order to make their way to Syria to join ISIS.

The girls, ages 15, 16 and 17, had skipped school and run off with a few thousand dollars in cash.

Why?  What could have been happening inside the minds of three young American women to make them want to join an army that beheads hostages, slaughters “infidels,” rapes women and swears that it will destroy the United States? 

Are these girls radically-minded, would-be soldiers, with deeply held religious, cultural and political beliefs or are they empty-headed, naïve recruits drawn unwittingly into a cult of darkness?

Answering that question definitively relies on interviewing the young women and researching their histories.  And it would be wrong to assume that teenagers are too young, or females too sensitive, or Americans too far from the battlefield in Syria, to betray our country and join a savage enemy army.

But it could also be the case that ISIS is no different for some American teenagers than Slenderman, the Internet meme “for” whom two 12-year-olds, Morgan Geyser and Anissa Weier, allegedly stabbed their classmate 19 times back in May.  Because the Internet has the power to animate, dramatize and disseminate even imaginary characters and ideas with such addictive and absorbing force that it seems to inhale some vulnerable psyches, fill them with incredibly bizarre ideas and not let them go.

Is joining ISIS just going one concrete step further for some young adults in America than playing Wartune, an interactive game in which players enter a dark fantasy world and take on the role of knights or archers who do battle with one another?  Some Wartune players, after all, have spent tens of thousands of dollars to outfit their characters with wings and special skills in battle.  How hard would it be to recruit the most avid users of such games, who are likely the most anemic in their internal self-concepts, to fight in a faraway land for an army of bloodthirsty lunatics wearing black hoods and sweeping across the desert?

How much have reality and self-determination, after all, been diluted by drowning ourselves and our children in the waters of Facebook and Twitter and Snapchat and YikYak and YouTube?  How vulnerable have our teenagers become to any dramatic message coming through the Internet medium?

In the end, it may be that we learn it is less relevant what was inside the minds of the three teenagers detained on their way to Syria to fight with ISIS than what was not in their minds—namely, their own opinions, their own ideals and their own senses of what is real, what is fantasy, where they are in their lives and where they are going.

Dr. Keith Ablow is a psychiatrist and member of the Fox News Medical A-Team.