A new study published in the journal PeerJ shows that an implanted device that targeted particular regions in the brain of a single patient with obsessive-compulsive disorder (OCD) diminished his symptoms and improved his everyday life significantly.
Precision medicine combines genomic, epigenomic and environmental data along with patient information behavior and allows researchers and health care professionals to design preventive and diagnostic solutions to prescribe the most appropriate treatments based on the patient’s unique characteristics.
G.J. Lyon, geneticist and psychiatrist from Cold Spring Harbor Laboratory’s (CSHL) Stanley Institute for Cognitive Genomics, and collaborators, report on the recruitment and the two-year treatment of a 37-year-old U.S. military veteran with a chronic, severe OCD. Given the failure of several treatments and the severe professional and personal impairment caused, researchers considered him an appropriate candidate for surgical implantation of the Medtronic Reclaim Deep-Brain Stimulation (DBS) Therapy device for OCD.
OCD is an anxiety disorder characterized by recurrent, unwanted thoughts (obsessions) that result in certain uncontrollable rituals or behaviors (compulsions).
The use of DBS device in the OCD began in 1998 at the Karolinska Institute in Stockholm after several applications for the treatment of movement disorders, Parkinson’s disease and depression. The implanted device targets a specific brain area (the nucleus accumbens/anterior limb of the internal capsule) which has been shown particularly activated when OCD symptoms are present.
The patient of the present study had a lifelong history of severe obsessions and compulsions (including contamination fears, scrupulosity, and the fear of harming others), periods of depression with suicidal ideation, three suicide attempts and some episodes of paranoia relating to anxieties from his OCD.
Since implantation, he showed steady improvement in his global functioning as well as in his score in the Yale-Brown Obsessive Compulsive Scale (YBOCS). However, the researchers noticed that when the battery drained his psychiatric symptoms immediately and significantly worsened, leading once to a major 24-hour relapse. As a consequence, the initial single-use battery was replaced by a rechargeable (but still depletable) battery, which could assure a better stability and control over the stimulation. On the one hand, this provided substantial evidence for the efficacy of DBS therapy. At the same time, it raises serious ethical issues such as a patient’s self-control and autonomy over symptoms and treatment, and equal access to treatments and special genomic counseling. In any case, DBS therapy demands a high implication and understanding of the patient so that he will make sure to keep the device charged.
In parallel, the scientists sequenced the entire genome of the patient and found at least three mutated genes previously associated with an elevated susceptibility to psychoses. Variations in the genes that encode three proteins (called MTHFR, BDNF, and ChAT) were found to be of potential clinical relevance for the patient as they are all implicated in contributing to the development of many of his neuropsychiatric symptoms. Other gene variants were found that have implications for the way the patient is either able or unable to metabolize particular drug molecules.
Comparatively, the implanted DBS device has been shown to have a more direct and effective impact on his treatment or prognosis than anything else discovered from the patient genome sequence. However, health information stemming from these genomic data can immediately inform the clinician and enrich one’s care. It is expected to be of a great use in the future too, as our understanding of human biology and the genetic architecture of disease improves. Dr. Lyon notes that the sooner genomic data are obtained in one’s medical course the better it is for the patient, as guidance on which medications to avoid or to prefer can be provided.
This study points out the potential benefits of a more holistic approach such as the precision medicine for curing diseases such as OCD. Incorporating insights from a range of scientific and clinical disciplines into a person’s evaluation, treatment and preventive care is emerging as a necessity. This should come along with policy changes that allow everyone to have access to and benefit from his own genome data. Research in these areas must continue, so that brain-machine neural interfaces used in humans will be optimized in the future, and help in the treatment of many psychiatric disorders.