As many as two thirds of all psychiatric patients do not respond well to treatment with drugs.
While compliance and frequent side effects play a major role, there are also genetic variations
which determine whether serious side effects occur, and which can also prevent medication from
working. An international consortium led by Dr Roos van Westrhenen (Maastricht
University/Parnassia) is to conduct a pharmacogenomic study to establish the relationship
between response to treatment and genetic background. This will make it possible to individually
tailor the drugs prescribed to psychiatric patients, and thus make therapy more effective. The
research was recently awarded eight million euros in European funding.

Pharmacogenomics

Due to the chronic and recurring nature of psychiatric disorders, paired with overall increasing life
expectancy, the social burden of mental illness will only continue to increase. This development
shows the need to make medication in psychiatry more effective. Pharmacogenomicsis the field
that aimsto use a knowledge of variationsin human DNA to explain why medicines cause many side
effects in some people and/or show little or no efficacy in others. Variations in DNA can lead to
differences in the activity of proteins that enable the body to absorb drugs. Although
pharmacogenomicsis increasingly being applied in the Netherlands, for example in oncology, until
now it has hardly been used in psychiatry. ‘Medication is often prescribed in psychiatry through a
trial-and-error approach, mainly based on the experience of doctors,’says lead researcher Roos van
Westrhenen. ‘Recent studies show that determining genes involved in drug metabolism can increase
the effectiveness of treatment. Millions of patients can benefit.’

Therapy

The international consortium, which apart from Maastricht University also includes the University of
Groningen and the mental healthcare provider Parnassia Groep, will use artificial intelligence to map
pharmacogenomic characteristics. At the same time, it will conduct a large-scale clinical study
among people suffering from depression, psychosis, or anxiety, again using artificial intelligence to
create an algorithm to personalise drug prescriptions, thus reducing side effects and increasing
efficacy. ‘This research will form an important basis to tailor drug therapy more closely to the
individual,’ says Professor Bart Rutten, head of the Department of Psychiatry at Maastricht UMC+,
one of the centres participating in the clinical study. ‘It thus offers promising prospects to reduce
mental suffering among patients.