Deep brain stimulation in obsessive-compulsive disorder

To the Editor

We commend Farrand et al. (2017) on their report of the outcome of deep brain stimulation (DBS) in seven patients with treatment-resistant obsessive-compulsive disorder (OCD). The authors acknowledge the need for structured assessment of quality of life and qualitative assessments in future studies, and the centrality of multidisciplinary input throughout all phases of care.

Our own experience of DBS in treatment-refractory OCD comprises four implanted patients; we have also targeted the nucleus accumbens. The outcomes thus far have been encouraging, albeit heterogeneous: one patient had a dramatic, almost total resolution of OCD symptoms, while the others have had a slower improvement trajectory. Clinical heterogeneity, psychiatric comorbidity and lack of clear treatment response predictors bedevil the work-up and prognostication. We have focussed on the severity and impact on daily life of the obsessive-compulsive symptoms as our primary target, aligned with the RDoC approach; this raises the possibility of using DBS in OCD-related disorders. Related to this is our use of magnetoencephalographic and positron emission tomographic imaging along with neuropsychological assessments to try better to understand the underlying neurobiology. Of interest is that patients seem to show, along with improved core symptoms, enhanced episodic (declarative) memory for situational awareness using the Autobiographical Memory Interview. Our patients (and their families) have described how difficult it can be to come to terms with a ‘life after OCD’: this has been described as the ‘burden of normality’ and requires careful attention in the planning and follow-up phases (Gilbert, 2012). We concur with Farrand et al. (2017) about the importance of a multidisciplinary team approach. We have found in particular that the inclusion of an expert mental health occupational therapist in the work-up and follow-up, within in-reach into the patients’ own living environments, to be a seminal component of recovery. We have also found that patients are able to re-engage in Exposure and Response Prevention exercises when they are less overwhelmed by their symptoms, post implantation.

Although the use of DBS in OCD can have excellent outcomes in individual patients, more consistent clinical staging for treatment-refractoriness, prognosis and response along with more personalized DBS treatment algorithms are required. Also, psychological and life skill multidisciplinary interventions, in context of the subjectivity of quality of life beyond obsessive-compulsive symptomatology, are imperative. We call for an Australia-wide network of all those involved in this work, to pool knowledge and help refine this work.