“Depression is like the economy”

She reached out to the Department of Quantitative Economics at Maastricht University with the idea of joining forces. It turned out to be a good move. “They have more knowledge of building these kinds of complex models, we have our clinical expertise in treating depression. Together we were able to set up a great interdisciplinary partnership.”

Seven-year project

The collaboration with the Quantitative Economics department, in particular with econometrician Nalan Bastürk, led to the development of a project that started last January and will run for seven years. The aim is to be able to make predictions, for the first time, for a diverse group of patients with depression. To this end, the researchers will set up a model based on Bayesian statistics. “The model will draw on data from a large number of previous studies and input from experts in the field, patients and family members.”

The story behind the prediction

Van Bronswijk and her colleagues aim to make a handy computer program for use in the consultation room. During an intake interview with the patient, the psychologist or psychiatrist can enter additional information that the model uses to make its calculations. Practitioner and patient then receive a clear answer that can help them choose a treatment. “Soon the program will also be able to tell the story behind its recommendation,” Van Bronswijk says. “So it will say, ‘This treatment is probably best due to the severity of the depression, certain past characteristics, and the current home situation. But we’ll keep measuring and predicting, as other factors may increase in importance.’ Because something can happen suddenly in the patient’s life that completely changes the prediction. If you don’t have a model, it takes time to realise that.”

The most appropriate treatment depends on not only the initial situation and the occurrence of sudden events, but also the patient’s goals. “Typically they want to reduce the symptoms of depression, but they may have other goals too—returning to work, finding meaning in their lives.” The model will therefore predict different treatments for different goals, such as quality of life. “It may be that one treatment scores slightly better on reducing the severity of the depression, while another scores slightly better on quality of life. The therapist and patient can decide together what to give more weight to.” Van Bronswijk hopes that the computer program will soon support the joint decision-making process of therapists, patients and their loved ones. During the project, she will test it at four different mental health institutions.

Culture change

Some resistance to the implementation of the program is to be expected. Psychiatrists and psychologists may fear that the computer will usurp their role and make decisions for them. Van Bronswijk would like to offer reassurance. “What we’re trying to do is build a bridge between researchers and clinicians. It’s extremely difficult to predict the outcome of a treatment yourself, no matter how much expertise you have as a psychologist or psychiatrist. A model like this can be a useful tool. We’re not saying the computer can do everything better—in fact, we want to involve practitioners in the process and draw on their expertise to build the model.”