A new US study reveals that PET scan could quickly assess the response to antidepressant treatment.
Depression is a very heterogeneous disease, which makes it extremely difficult to treat effectively according to Mala Ananthe of Stony Brook University in New York. In particular, it is difficult to predict before 3 to 4 weeks of treatment its real effectiveness.
Researchers have developed a new method for early assessment of the response to antidepressant treatment using a PET scan, a special scanning technique that analyzes the attachment of a marker in active areas of the body. Their findings were published in the Journal of Nuclear Medicine in April 2018.
The effectiveness of an antidepressant treatment can not be evaluated before an almost incomprehensible time of 3 to 4 weeks in order to possibly adjust the dose or to note the failure and to change the treatment. In addition, patients who resist first-time treatment have a progressively increasing risk of resisting other treatments. Unfortunately, no marker currently makes it possible to estimate the treatment response and efficacy of the treatment at an early stage.
To respond to this challenge, US researchers have developed a positron emission tomography (PET) imaging assessment method that could predict in advance whether a specific treatment is likely to be effective against a depressive disorder.
The tracer developed by the researchers targets the transport protein serotonin (5-HTT), a neurotransmitter very involved in depression, inside a structure of the brain, the amygdala, which is part of the brain circuits affected by depression. PET-scan allows to measure the level of this protein before and after the beginning of the antidepressant treatment, knowing that the rate of this protein is the reflection of the connection between 2 critical areas of the brain critical in depression, the midbrain and the amygdala . However, the researchers found that in depressed patients who did not have any remission after 12 months of treatment, the connection between the midbrain and amygdala is weaker.
A PET-scan can therefore indicate, according to the 5-HTT level measured before the treatment, which patients will be improved by the treatment. In addition, the quantification of the link between the midbrain and the cerebral tonsil under treatment could constitute a potential biomarker for remission after antidepressant treatment.