OCD, while fairly common, can be difficult to treat. Conventional treatments like psychotherapy and medication often fall short for a significant portion of the population.
Transcranial Magnetic Stimulation (TMS) offers a safe and effective alternative or addition to traditional treatments for OCD, particularly for treatment-resistant cases.
Research consistently highlights the efficacy of TMS, especially Deep TMS (dTMS), in reducing OCD symptoms by targeting specific brain regions implicated in the disorder, providing hope for those struggling with treatment-resistant OCD.
Introduction
Obsessive-compulsive disorder is a common and debilitating chronic psychiatric condition which can, if left untreated, overshadow a patient’s life. Traditional forms of treatment such as psychotherapy and medication can be effective at addressing the root causes of the disorder and reducing symptoms. However, a significant portion of the general population are treatment-resistant and have limited results from these traditional treatments. TMS can be a safe and effective alternative or addition to these treatments, providing patients with significant relief.
What is OCD?
Obsessive-Compulsive Disorder (OCD) is a chronic psychiatric disorder thought to affect roughly 1% of the general population [1]. The common symptoms of this condition can be separated into groups: obsessions and compulsions. Obsessions are defined in the DSM-5 as recurrent and persistent thoughts, urges or images that are experienced as intrusive, unwanted, and that in most individuals cause marked anxiety or distress. Compulsions are defined as repetitive behaviours (e.g., hand washing, ordering checking) or mental acts (e.g., praying, counting, repeating words silently) that the person feels driven to perform in response to an obsession [2]. In order for a clinical diagnosis of OCD to be made, the obsessions or compulsions must be time consuming (e.g., take more than 1 hour per day) or cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. The symptoms must also not be better explained by other psychiatric disorders such as generalised anxiety disorder (GAD), eating disorders such as bulimia or anorexia, schizophrenia, or psychosis [2].
OCD can affect people of all ages, genders and backgrounds. However, research has shown that it tends to be more prevalent in women (1.5%), than men (1.0%) [1]. The condition usually begins presenting in adolescence, although it has been documented in children as young as 4 years old [3]. There are several risk factors that can increase a person’s chance of developing OCD. These include having a first-degree family member (parents or siblings) with OCD, childhood trauma, and pregnancy [4].
Treatments for OCD
As with most psychiatric conditions, treatment of OCD usually involves a combination of psychological interventions such as CBT or exposure therapy, and prescribed antidepressants such as selective serotonin reuptake inhibitors (SSRIs) [5]. Psychological interventions are employed to address the root causes of a patient’s obsessions and compulsions, whereas the medication is used to reduce and manage symptoms. However, this approach does not work for everyone. Psychological interventions like therapy, are often a long, arduous and expensive process, which many patients find overwhelming and difficult to commit to [6]. Medication, while having the potential to reduce symptoms within a relatively short amount of time, can often cause unwanted side effects such as fatigue, nausea, sleep disturbance, loss of libido, weight-gain, and addiction. Furthermore, recent research has found that 20-60% of psychiatric patients are treatment resistant, meaning that their prescribed medication will have little-to-no effect and may require alternative treatments [7].
TMS treatment for OCD
TMS is a noninvasive treatment that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of several psychiatric disorders. It is generally only prescribed to treatment-resistant patients who have already tried other methods such as medication or psychotherapy. It works by delivering electromagnetic pulses to specific areas of the brain, which can adjust brain activity and improve symptoms. In patients with OCD, fMRI studies have shown hyperactivity in areas of the brain including the medial prefrontal cortex (mPFC) and the anterior cingulate cortex (ACC) [8]. TMS treatment of OCD stimulates these areas of the brain to stabilise neural activity and reduce symptoms.
Research shows that stimulation using either repetitive transcranial magnetic stimulation (rTMS) or deep transcranial magnetic stimulation (dTMS) over the mPFC or ACC to be effective at reducing OCD symptoms. For example, one study found that patients treated with active TMS responded (symptom reduction of at least 30%) nearly four times as much as patients treated with sham TMS [9]. These findings are supported by another study, finding that more than four times as many OCD patients responded to active TMS rather than sham [10].
These findings are generally consistent throughout the literature, with one meta-analysis of 10 randomised controlled trials (RCTs) finding a response rate of 35% in TMS treated OCD patients vs. 15% for sham TMS treated patients [11]. Similarly, several other meta-analyses have all found TMS, whether dTMS or rTMS, to be significantly more effective than sham treatment at reducing OCD symptoms [12,13,14].
dTMS vs. rTMS treatment for OCD
While TMS, in general, has been shown to be a safe and effective treatment for patients with clinical depression, there are a number of different TMS systems available to patients, which use different treatment protocols and magnetic coils to provide stimulation. The most commonly used coil is known as the Figure-8 (F8) coil, which most TMS manufacturers use. However, there is a more advanced coil called the Hesed-coil (H-coil). The H-coil was patented by Brainsway and is used exclusively in Brainsway machines. The difference between these 2 coils is that the H-coil is able to stimulate deeper regions of the brain than the F8 coil, which is why H-coil TMS is often referred to as Deep TMS (dTMS). This difference is highlighted in the literature, with a recent review finding that dTMS produced larger response and remission rates than rTMS [15].
Conclusion
Obsessive-Compulsive Disorder poses a significant challenge for those affected, necessitating effective and accessible treatments. While conventional therapies provide relief for many, a notable portion of patients remains resistant to these approaches. Transcranial Magnetic Stimulation (TMS), particularly Deep TMS (dTMS), has emerged as a safe and effective option for OCD treatment. By targeting specific brain regions implicated in OCD pathology, dTMS demonstrates superior efficacy when compared to standard rTMS. Research consistently underscores the favourable outcomes of dTMS in reducing OCD symptoms, offering hope for those grappling with treatment-resistant OCD. As advancements in neuromodulation continue, dTMS stands poised to revolutionise OCD treatment, providing a beacon of hope for patients navigating the complexities of this challenging disorder.
References
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2. Substance Abuse and Mental Health Services Administration. Impact of the DSM-IV to DSM-5 Changes on the National Survey on Drug Use and Health [Internet]. Rockville (MD): Substance Abuse and Mental Health Services Administration (US); 2016 Jun. Table 3.13, DSM-IV to DSM-5 Obsessive-Compulsive Disorder Comparison. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519704/table/ch3.t13/
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