Substance use and the presence of subthreshold affective symptoms may predict future bipolar disorder in young people with precursor conditions such as depression, suggests an article in News Medical. People with a family history of any substance abuse disorder and poor physical health quality of life were at an increased risk of converting to bipolar disorder. Also, those having subthreshold hypomanic or manic symptoms were at an increased risk of converting. To read this article in its entirety, click here.