Final answer:
Excessive internet use has been linked to negative outcomes like social isolation, poor academic performance, and increased depression and anxiety, but not to improved sleep quality.
Step-by-step explanation:
Excessive internet use has been associated with a range of negative consequences, but improved sleep quality is not one of them. Extensive research indicates that excessive use of the internet, and particularly social media, can lead to social isolation, poor academic performance, and an increase in depression and anxiety. For instance, social media stress and increased screen time are known to contribute to sleep disruptions and poor sleep quality, impacting overall health and cognitive function. Studies have highlighted that behaviors such as watching too much television or engaging in excessive internet usage can interfere with a student's ability to prepare for exams, leading to poorer performance academically. There's also a correlation between heavy internet use and issues such as insomnia, lack of interest in daily activities, and difficulties in learning new tasks. Furthermore, the stress and hyper-connected nature of online environments can make it challenging for people to focus, maintain undivided attention, and effectively manage work-life balance.
Therefore, the correct answer to the question 'Excessive internet use has been associated with all of the following except:' is c) Improved sleep quality.