SF State University Study (IMAGE) San Francisco State University Caption A study of 135 SF State University students found that the heaviest smartphone users were the most depressed, anxious and lonely. Credit San Francisco State University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.