Teenagers are in such a fragile age of exploration. And for some, this means exploring substances that are generally frowned upon such as drugs, followed by alcohol. With this in mind, the question is: who is most at risk in falling to these destructive habits?

Scientists at Duke University have conducted a study to find out what teenagers are getting themselves into and on the way, have made significant discoveries as to which race or ethnic group are affected.

Based on their findings, which was collected from a national survey of 72,561 adolescents ages 12 to 17 from 2005 to 2008, 37% admitted to have used alcohol or drugs in the past year. Out of this percentage, 7.9% met the criteria for substance use disorder, which meant the substances have already affected their lives in terms of relationships or legal problems.

Among those who were surveyed, Native American teens topped the list when it comes to alcohol use with 37%, followed by whites with 35.3%, and Hispanics at 32.2%. African-Americans and Asians were among those who had the lowest percentages of alcohol users, 24.8% and 18.9% respectively.

When it comes to drug use, the pattern was similar with Native American teens leading with 31%, children with multiple-ethnicities followed with 23.3%, and whites at 20%. Hispanic and African-American youths were at 18% while Asians had the lowest rate at 11.7%.

Substance of choice among these teens was marijuana, with 25.9% of the teens having a dependence problem with it. Marijuana, according to Dan C. Blazer, from Duke's Department of Psychiatry and senior author of the study, was used more than twice than other drugs.

In fact, abusers said that they had used marijuana for an average of 79 days just in the last year. Other stimulants ranked second for the number of days in use with 47 days, followed by opioids - which is prescribed to treat pain - at 39 days and alcohol at 36 days.

Now that the populations of teenagers who are abusing substances have been identified, the question now is: why do they use drugs?

There are various factors as to why teens turn to drugs, according to MayoClinic.com. Some of the reasons behind this could be from family history of substance abuse, depressions, low self-esteem, lack of parental guidance, poverty, or availability of substances.

Parents are extremely important in guiding their children away from these substances. But what can parents do to help their child veer away from the calling of various substances? According to About.com's Denise Witmer, there are some tips that parents can follow to help prevent their teens from using drugs.

1. Parents should be there for their teens when they need to get out of a bad situation

2. Know the teenager's friends and their parents

3. Keeping in touch with them after school hours

4. Having conversations with them regarding drugs

5. Getting teenagers involved in extra-curricular activities

6. Asking questions on teenagers' plans when going out

7. Being a role model