GAIA is a public health company that specializes in the development of eHealth and mHealth interventions. Located in Hamburg, Germany, the company is comprised of multidisciplinary teams of currently 40 employees (e.g., psychologists, physicians, communication designers, graphic designers, software engineers, mathematicians, natural scientists) and has developed more than 50 interventions since its inception in 1997, some of which have been evaluated in randomized controlled trials (RCTs) and published in peer-reviewed articles. The company specializes in the development of programs for patients with mental health conditions (e.g., depression, anxiety, personality disorders, substance misuse) or with physical illness (e.g., acute and chronic back pain, diabetes, fatigue in multiple sclerosis, HIV) as well as programs for physicians (e.g., continuing education in statistics and research methods, pharmacology, psycho-oncology, depression treatment guidelines).

To provide as example, GAIA has developed an online treatment program for patients suffering from unipolar depression ("deprexis"), which has been evaluated and found to be efficacious in six independent RCTs. In terms of efficacy, the program has been favorably compared with other interventions in recent reviews and meta-analyses. Current deprexis-related RCTs are funded by the German Ministry of Health and Ministry of Education and Research. Additional ongoing research projects with deprexis focus on identifying genotypic predictors of treatment response, among others. Like other GAIA programmes, deprexis is available in multiple languages (in the case of deprexis: in German, English and Swedish) and exceeds industry standards in terms of data security (e.g., deprexis is the first software to be certified as a medical device in Europe; CE certification).

GAIA has also developed online programs that focus on conditions other than depression. For example, a web-based screening and intervention program for teenagers with poly-drug use ("Wiseteens") has been developed in collaboration with the German Centre for Addiction Research in Childhood and Adolescence, University Medical Centre Hamburg-Eppendorf and is currently being evaluated in an EU-funded trial. In another project, GAIA has developed an online decision-aid program for patients suffering from low back pain and/or depression (the "Patient Dialogue"). This project was conducted in collaboration with a German statutory health insurance and the University Medical Centre Freiburg; a randomized controlled trial showed that using the program resulted in reductions in treatment decision-conflict and improvements in the patients' sense of being prepared for physician consultations.