Wolfgang Werner Wittman, from the University of Mannheim, has spent the past six years examining data collected from 1,000 patients in Hamburg, who were being treated using behavioural and deep therapies.
The cost-benefits analysis results of his research are clear. "An investment of one euro, pays back two or three. When someone can return to the workplace, clearly they are more productive than when they are not working and receiving welfare benefits."
A Bavarian study has also shown similar results.
In Germany, only qualified psychiatrists and psychologists are allowed to practice psychotherapy. In Austria however, 'academic' training is not required.
Psychologist Anton Laireiter of the University of Salzburg believes it's time Austria carries out a study on the quality of therapies offered to patients.
His attempts to begin such a project have so far failed.
"Most psychotherapists sit back and say that this subject is researched internationally, and they know that it's all more or less equally effective," Laireiter said.