A possible pathway to depression was considered to be via stress and sleep disorders, and it was suggested that the demand for constant availability could interfere with recovery. Unreturned calls or SMS messages could lead to feelings of guilt. There was also a notion that not being available could lead to being left out. Social isolation was more evident when the phone didn’t ring. It was also suggested that mobile phone use might decrease personal contact in real life and thus increase social isolation. The quality of information or communication received via mobile phone could be destructive; for example, negative information received at the wrong time and place, or harassing phone calls or messages. It was considered easier to send negative messages (breaking up a relationship, for example) via SMS than to deliver them face to face, and so there was a perception of a higher risk of receiving bad information via mobile phone than receiving it through other channels. Jealousy in relation to others’ phone use was also mentioned, as were feelings of inadequacy in response to receiving messages about others’ good fortune. Electromagnetic radiation was suggested as another link to depression. (Avvannavar SM etal.2008, P.82).