There is a complicated nexus between genes, environment and drug response. Studies in genetic variability would help to understand drug response in the mentally ill who are drug-resistant.

There are several stigmas linked to depression, but studies have revealed that it is a medical illness just like diabetes or a heart condition. This condition does not merely affect the mind but makes an impact on the entire being of a person.
Untreated depression often leads to suicide but the good news is that depression is treatable. The majority of individuals who receive treatment go on to make full recovery.
The individualized treatment approach has revolutionalized treatment for depression by optimizing the effectiveness of the treatment and by reducing side effects.
Genetic factors play an important role in a person’s response to drugs and in the side effects that he suffers; however one study has found that environmental factors have a greater role to play!
It has been understood that there is a complicated nexus between genes, environment and drug response. It is hoped that studies in genetic variability would help to understand a person’s response to medications for mental illness, particularly in those who are drug-resistant.
Detecting specific “candidate” genes would allow the therapists to predict the manner in which an individual metabolizes a medicine. This in turn would enable doctors to choose the correct therapy that is most suitable for that patient, thereby, helping to reduce side effects.
In January 2005, the FDA approved the Roche AmpliChip CYP450 genotyping test for variants in the gene CYP2D6 and CYP2C19, using the patients DNA derived from buccal or blood samples. The test helps therapists to determine appropriate treatment plans, including dosing, for medications metabolized by CYP2D6 or CYP2C19. It analyzes the patient’s DNA to predict if he or she –
· has more difficulty reaching therapeutic concentrations;
· responds normal medicine metabolizing capacity
· experiences more adverse effects;
· is a poor metabolizer and at higher risk for overdose.
Although genetic testing may influence treatment choices, current data is not adequate enough to be conclusive. However, with further research the dream of personalized therapy is soon likely to become a reality!
Reference: Pharmacogenetics and Depression: Realized Dream or Great Expectation?; Jolene et al; US Pharm. 2011;36(11):72-76.
Source-Medindia