text: Facebook is often linked with depression, social anxiety and other mental health issues. But a new scheme hopes to reverse this reputation by using the site to instead find cures and improve treatments for diseases using the DNA of its members. Genes for Good is a Facebook app designed to survey the health of millions of social network users, who can also submit spit samples to tie their survey results to their genes. Genes for Good (pictured) is a Facebook app designed to survey the health of millions of social network users, who can also send in spit samples to tie their survey results to their genes. It was set up by biostatisticians from the University of Michigan and is available over 18s in the US . It was set up by biostatisticians from the University of Michigan, and although the app is hosted by Facebook, the site is not affiliated with the scheme in any other way. The app is available for free from Facebook's store but is only currently open to people aged over 18 with a valid mailing address in the US. The researchers don't have any plans to extend it outside of the US at the moment, but this may change depending on how successful the scheme is. Once a user has read and accepted the terms and conditions, which doubles up as a consent form, they are presented with health surveys they  complete each day. Sending a spit sample is voluntary, and users only become eligible once they've completed 15 of the Health History Survey questions, and each of the Health Tracking Surveys over two separate days. The app is available for free to people aged over 18 with a valid mailing address in the US. Once a user has read and accepted the terms and conditions they are presented with health surveys they can complete each day. Sending a spit sample is voluntary, and users only become eligible once they've completed 15 of the Health History Survey questions, and each of the Health Tracking Surveys over two separate days. Participants can withdraw at any time by clicking the withdrawal link in the Facebook app under the 'Your Account' option in the upper right corner of the site. After withdrawing, Genes For Good keeps the survey responses but deletes the participant's name and unique Facebook ID from its database. It also removes addresses, including an IP address and physical address, and phone numbers but keeps their age, sex, and zip code information. It also keeps the DNA. These questionnaires relate to a user's health, habits, attitudes, and relationships and the Health Tracking Surveys provide detailed information about how a person's health changes over time. After completing each survey, uses can view their own results as well as see summaries about other how these results compare to other participants. Once requested, a 'spit kit' is sent free of charge and the firm said DNA obtained from this sample will be frozen and 'stored indefinitely' in a secure laboratory supervised by the researchers. The researchers explained: 'Our goal is to accelerate genetic and health research using social media. 'We will use the information you provide to advance our understanding of genetics, disease, behaviour, human ancestry, and our relationships around the world. 'The findings from this research may benefit many individuals, for generations to come, as we learn more about how our genes affect our lives. 'You can also use capabilities in Genes for Good to track your lifestyle, habits and activities, and compare yourself to other participants. Each member who submits a spit sample will also see a copy of their results, which include their genetic ancestry as well as raw genetic data  in a securely encrypted computer file. Similar services, such as those offered by genealogy sites like Ancestry, cost $99 in the US and £99 in the UK. This applies to the first 2,000 kits sent out by Genes For Good. The scheme has not revealed whether kits will then need to be paid for, or if this is a limited number. MailOnline has contacted the university for more information. Sending a spit sample (illustrated) is voluntary. Each member who submits a sample will also see a copy of their results, which include genetic ancestry as well as raw genetic data in a securely encrypted computer file . 'We use Facebook because of its vast existing social network, continued the researchers. 'Using Facebook will allow the study to grow both quickly and optimally through word of mouth. 'Otherwise, the study is independent of Facebook. Facebook cannot access the information you provide to Genes for Good. 'You can stop participating at any time. You can stop answering surveys or you can delete the app from your Facebook account.' Apple recently announced an initiative called ResearchKit that plans to gather health data from iPhone users. It will use, on a voluntary basis, data from medical tracking apps to help research asthma, breast cancer, cardiovascular disease, diabetes and Parkinson’s disease. Apple's senior vice president of Operations Jeff Williams said: 'ResearchKit is made for medical researchers, it lets them easily create apps.' Apple worked with University of Oxford, Stanford and others to develop this project. The Genes For Good's connection with Facebook may concern privacy campaigners following claims earlier this week that the social network tracks users, even if they've opted out. Facebook has more than 1.3 billion users but there are millions more visits from people who are not signed up. Researchers from the University of Leuven said Facebook puts tracking cookies on internet users' laptops, PCs and phones when the visit facebook.com so it can target them with online advertising. But Facebook today said the report is inaccurate and the researchers had persistently ignored its request to meet. A spokesman said: 'This report contains factual inaccuracies. The authors have never contacted us, nor sought to clarify any assumptions upon which their report is based. Neither did they invite our comment on the report before making it public. 'However, we remain willing to engage with them and hope they will be prepared to update their work in due course.' 'Earlier this year we updated our terms and policies to make them more clear and concise, to reflect new product features and to highlight how we're expanding people's control over advertising. Members can withdraw at any time and after withdrawing, Genes For Good keeps the survey responses but deletes the participant's name and unique Facebook ID from its database. It also removes addresses and phone numbers, but keeps their age, sex, and zip code information. It also keeps the DNA (stock image) We're confident the updates comply with applicable laws including EU law.' After withdrawing, Genes For Good keeps the survey responses but deletes the participant's name and unique Facebook ID from its database. It also removes addresses, including an IP address and physical address, and phone numbers but keeps their age, sex, and zip code information. It also keeps the DNA. And Genes For Good said there are also risks: 'We have taken important steps to reduce this risk, including the utilisation of separate independent servers to host the web application and your responses and genetic data. '[But] If the genetic information is used in some way to identify you, it is possible that you could suffer psychological or emotional harm, or other unforeseen consequences.' It said that the Genetic Information Nondiscrimination Act of 2008 (GINA) is a federal law that protects individuals from genetic discrimination in health insurance and employment, and genetic counsellors can also be used to seek advice or support.
target: The app was designed by researchers at the University of Michigan .
  Participants complete Health Tracking Surveys via an app on Facebook .
  They can also send a spit sample that is tied to the results of the surveys .
  Researchers said they hope to use  results to help find cures for diseases .