I work closely with a genetic testing company Myogenes which is an advanced technique in looking at DNA analysis. This expensive test (under £1000) can help identify various differences within people as to why medication may either cause side effects or alternatively become ineffective.
The test looks at two sets of genes one to do with how the brain is constructed and the types of receptors that deal with neurotransmitters are functioning and secondly sets of genes to do with the metabolism of medication. Some people have genetic variance which means they metabolise drugs very quickly and hence give very low blood levels which can cause an ineffective treatment outcome.
The tests gives some indications of widely used medication as to whether or not they are likely to cause problems. This approach of genetic testing will undoubtedly become mainstream in the next few years. I think that they will be able to provide a better analysis of more neurotransmitters systems and more metabolic pathways as the technology develops.
The test is taken with a buccal (mouth) swab. It is sent to America for analysis and I have a thirty minute telephone consultation with one of the technicians to help interpret these difficult results. You would get a copy yourself. I may suggest this investigation in order to provide better outcomes in the treatment of your condition.