In this study, the prevalence of internet addiction was 31%. Internet addiction was significantly associated with using internet at the college, spending 5 h or more using the internet per day, and using the internet for social networking. The prevalence of internet addiction in this study was higher than that reported from the USA [4, 19], Asia , and among African countries [21, 22]. A slightly higher prevalence (37%) was reported in Malaysia and Iraq [9, 10] as well as (40.7%) in Iran . Variations in prevalence could be due to differences in the tools used. For instance, a study in Iraq  utilized an 8-item scale as opposed to the 20-item scale used in this study. In contrast, [16, 21] utilized a modified version of the scale, and  used a different tool (i.e., Chen Internet Addiction Scale) to assess internet addiction. Higher prevalence may also be attributed to internet access using personal devices, considering that more than 70% of all respondents in this study accessed the internet using their mobile devices.
The higher prevalence of IA in this study may have serious implications for both social, mental, and physical health as well as financial consequences. The combined effect of these problems could have serious implications for academic performance [2, 16, 28, 29]. For example, problems with self-care, difficulty in performing daily routine, pain and discomfort, anxiety, and depression were the consequences of internet addiction reported among young Vietnamese population (15–25 years of age) comprising a mixture of high school and university students . Other literature reported consistent findings, which also included additional critical mental, physical, and social problems associated with internet addiction among university students [1, 3, 4, 9, 11, 15, 17, 22, 24]. Internet addiction problems should, therefore, be addressed both as a public health and clinical problem focusing on reducing potential negative psychosocial consequences of risky/ harmful content, excessive/ maladaptive use, and financial burden , particularly on the high-risk populations. Mental health research in Tanzania is limited. We recommend more studies to assess the potential risk factors, consequences, and cost-effective as well as context-specific interventions to address the common mental health problems in the country, such as the alarming prevalence of internet addiction.
In this study, university students spending a long time (more than 5 h per day) on the internet increased the likelihood of internet addiction, which is consistent with findings from other studies [14, 16, 21, 24]. An excessive amount of time spent on the internet serves as a distraction from schoolwork. This situation puts students at a disadvantage in as far as academic productivity is involved . If used positively, the internet is potentially useful and informative both academically and socio-economically, and it is capable of assisting university students to achieve their lifetime goals [2, 22].
University students who reported using the internet for social networking were more likely to be addicted to the internet compared to those who used it for academic purposes. This finding concurs with other studies [2, 9, 16, 17, 21, 22, 30]. Like in other studies, the most commonly used social media platforms in this population included Instagram, YouTube, Snapchat, Skype, WhatsApp, and Facebook, among others [2, 30, 31]. These students could, therefore, be spending less time online engaging in academic activities, which are likely to affect their academic productivity or performance [2, 16, 28], which increases the risk of mental, psychosocial and physical consequences.
University students who were using the internet at the college were less likely to have internet addiction compared to those using the internet both at home/ hostel and college. In India, university students who stayed in rented accommodations were more likely to be addicted to the internet . Internet use through the college facilities might offer some protection against excessive use, by restricting the contents to academic-related materials. Concerted efforts by the college should ensure the availability, reliability, and regulation of college internet services to encourage learning and enhance academic performance, particularly on the campus premises.
While the current study has provided an overview of the current status of the burden of internet addiction among university students in Tanzania, it has several limitations. Firstly, this study used a cross-sectional design that does not allow drawing any inference on the cause-effect relationship of internet addiction and associated factors. Secondly, the study might have missed students who were severely addicted to the internet as they are more likely to miss classes. The tool utilized for data collection is a self-reported measure to assess internet addiction; hence is subject to potential information bias, particularly recall and self-desirability bias. Also, this tool has not been validated in the Tanzanian context, highlighting a need for a validation study. Lastly, these findings may not be generalized to students in other universities or the general population across the country.