Obsessive-compulsive disorders (OCD) comprise a group of mental illnesses characterized by recurrent compulsive actions and obsessive thoughts. Affected patients are severely restricted in all areas of everyday life, as the compulsions dominate their behavior. The main focus of therapy is cognitive behavioral therapy and drug therapy. For patients who do not respond adequately to conventional therapies, deep brain stimulation (DBS) is a novel and promising treatment modality. In the following, we provide an overview of the neurosurgical treatment options at Inselspital.

How does OCD manifest itself?

Obsessive-compulsive disorder can manifest itself in compulsive behavior or compulsive thoughts. In both forms, compulsion becomes the focus of motivation and dominates over other behaviors. Thus, on average, affected individuals spend about 7–8 hours a day dealing with their compulsions.

  • Obsessive-compulsive thoughts are ideas, conceptions or impulses that impose themselves on the affected person against their will. They are intrusive and intense and often difficult for outsiders to rationally comprehend.
    For example, sufferers have an excessive fear of contracting infectious diseases or of being poisoned, or they feel a compulsive urge for order and symmetry.
  • Obsessive-compulsive behaviors are mostly everyday behaviors that are repeated compulsively over and over again. Although the sufferers recognize their actions as excessive or pointless, they feel a strong urge to carry out the compulsive action.
    Examples of compulsive behavior are washing compulsions (repeated washing of hands until the skin is damaged), checking compulsions (repeatedly checking whether the front door is locked) or ordering compulsions (arranging objects according to certain principles).

What is the cause of OCD?

The exact causes of obsessive-compulsive disorder are unknown. Probably both genetic factors and environmental factors (especially social factors) favor the development of the disorder.

The central and common feature of OCD is the motivation to engage in certain behaviors and thoughts. It is therefore reasonable to assume that those areas of the brain that control motivation and reward are restricted in their function. This control is fulfilled by structures in the depth of the brain, including the basal ganglia. Dysfunction of certain parts of the basal ganglia forms the basis for deep brain stimulation (DBS) as a therapeutic measure.

What are the treatment options?

Diagnosis and treatment of obsessive-compulsive disorders should be done by experienced psychiatrists.

Cognitive behavioral therapy (CBT)

Cognitive behavioral therapyis a treatment of choice.

Drug therapy

Drug therapy can be supportive in severe cases.

Deep brain stimulation (DBS)

If the symptoms do not respond adequately to this multimodal therapy, deep brain stimulation (DBS) is a treatment alternative. It can be a promising treatment method in cases of severe obsessive-compulsive disorder for which conventional forms of therapy are ineffective.

Tiefe Hirnstimulation (DBS)

Study results on deep brain stimulation

Several studies have demonstrated the effect of deep brain stimulation. Similar to other disorders that can be treated with DBS, there are different target points in the brain whose stimulation leads to an improvement in obsessive-compulsive disorders. Common brain targets include the anterior limb of the internal capsule (ALIC), the anterior part of the subthalamic nucleus and the ventral striatum.
These are the expected effects of deep brain stimulation:

  • Reduction in the frequency of compulsive acts
  • Reduced urge to perform a compulsive act
  • Overall improvement in quality of life

Several studies have demonstrated the safety and positive effects of DBS for obsessive-compulsive disorder *, *, *, *. The response rate of patients across all studies is 50–60%, with an average reduction in symptoms of 40–60%.

More common side effects, most of which are transient, include depressed mood, increased agitation and impulsivity, and sleep disturbances. Severe side effects such as intracerebral hemorrhage or suicide attempts have been described much less frequently (4–6%).

Why you should seek treatment at Inselspital

Since obviously not all patients benefit equally from stimulation, good patient selection by an interdisciplinary team is a necessary prerequisite for a postoperative response to therapy. Criteria that eligible patients should fulfill have been laid down in corresponding guidelines *.

At Inselspital, all eligible patients are discussed individually on an interdisciplinary basis by experienced neurologists, psychiatrists and neurosurgeons. This is done at our monthly DBS board. The decision for or against DBS is then made in the best interest of our patients.


  1. Denys D, Graat I, Mocking R et al. Efficacy of Deep Brain Stimulation of the Ventral Anterior Limb of the Internal Capsule for Refractory Obsessive-Compulsive Disorder: A Clinical Cohort of 70 Patients. Am J Psychiatry. 2020;177:265-271.

  2. Mallet L, Du Montcel ST, Clair AH et al. Long-term effects of subthalamic stimulation in Obsessive-Compulsive Disorder: Follow-up of a randomized controlled trial.[letter]. Brain Stimul 2019;12(4):1080-1082.

  3. Menchón JM, Real E, Alonso P et al. A prospective international multi-center study on safety and efficacy of deep brain stimulation for resistant obsessive-compulsive disorder. Mol Psychiatry. 2019

  4. Vicheva P, Butler M, Shotbolt P. Deep brain stimulation for obsessive-compulsive disorder: A systematic review of randomised controlled trials. Neurosci Biobehav Rev. 2020;109:129-138.

  5. Hamani C, Pilitsis J, Rughani AI et al. Deep brain stimulation for obsessive-compulsive disorder: systematic review and evidence-based guideline sponsored by the American Society for Stereotactic and Functional Neurosurgery and the Congress of Neurological Surgeons (CNS) and endorsed by the CNS and American Association of Neurological Surgeons. Neurosurgery. 2014;75:327-33; quiz 333.