Teenagers who remain optimistic throughout their adolescence are less likely to develop depression or abuse drugs and alcohol to the point of needing substance abuse help, according to a new study from Australian researchers.

Depression is one of the leading factors that drive youths to substance abuse. Teens who feel unwanted or unpopular may turn to drugs and alcohol to cope with these emotions. Avoiding these problems may be important for carrying good mental and physical health into adulthood.

For the study, researchers from Royal Children's Hospital in Melbourne, Australia followed a group of more than 5,600 adolescents for a period of two years. The youths were surveyed about their general attitude and tested for symptoms of depression.

Investigators found that teens who had the most optimistic outlook were significantly less likely to show signs of depression. For example, 15 percent of boys who had the brightest outlook were diagnosed with symptoms of depression while 59 percent of those with low optimism scores were at risk for mood disorders.

The researchers said that keeping a positive attitude during this period of life, which can be rocky for many individuals, may be key to avoiding mental health problems and the substance abuse that often accompany these issues.