The longer young people watch television, the greater the risk of developing depression later in life, DPA quoted a US study as showing. Researchers at the University of Pittsburgh recorded the number of hours for 4,140 participants in the study who watched television in the year 1995. They also recorded how long they played at the computer or listened to the radio. The average age of the participants was then 14.8 years, and there was no indication any of them had depression. Seven years later, 7.8 per cent of the participants had been diagnosed with depression. The risk of depression developing rose concurrent with the amount of television watched. The study was reported in a medical journal published in Munich, which said depression may arise because people who watch a lot of television are left with little time for athletic or social activities. In addition, television programs could also increase fears and aggression. Another possibility is that people who watch a lot of television get too little sleep, which has a negative affect on cognitive and emotional development.