Can Brain Stimulation Help Treat Obsessive-Compulsive Disorder?

What you need to know

• A new brain stimulation technique called transcranial direct current stimulation (tDCS) may help reduce symptoms in people with obsessive-compulsive disorder (OCD)
• The study found that stimulating two key brain regions involved in OCD led to improvements in symptoms, anxiety, depression, and some cognitive abilities
• A higher intensity stimulation (2 mA) was more effective than a lower intensity (1 mA) or sham stimulation
• The treatment was well-tolerated with no serious side effects reported

What is obsessive-compulsive disorder?

Obsessive-compulsive disorder (OCD) is a mental health condition that affects 2-3% of people worldwide. It involves having unwanted, intrusive thoughts (obsessions) and feeling compelled to perform repetitive behaviors or mental acts (compulsions) to relieve anxiety. For example, someone might have obsessive thoughts about germs and feel compelled to wash their hands excessively.

OCD can significantly impact a person’s quality of life, relationships, and ability to function. While treatments like cognitive-behavioral therapy and medication help many people, about 40% of individuals with OCD do not respond adequately to standard treatments. This highlights the need for new treatment approaches.

A new approach: Stimulating key brain regions

Researchers have been exploring whether non-invasive brain stimulation techniques could help treat OCD by targeting brain circuits involved in the disorder. This study tested a technique called transcranial direct current stimulation (tDCS).

tDCS involves applying a weak electrical current to specific areas of the brain using electrodes placed on the scalp. This can temporarily increase or decrease brain activity in the stimulated regions. While the exact mechanisms are not fully understood, tDCS is thought to modify brain excitability and plasticity.

The researchers targeted two key brain regions implicated in OCD:

1. The left dorsolateral prefrontal cortex (DLPFC) - involved in cognitive control and executive functions

2. The pre-supplementary motor area (pre-SMA) - involved in inhibitory control, especially of ongoing actions

They applied anodal (excitatory) stimulation to the left DLPFC and cathodal (inhibitory) stimulation to the pre-SMA. The goal was to boost activity in the DLPFC while dampening overactivity in the pre-SMA.

Study design

The study included 39 adults diagnosed with OCD. They were randomly assigned to receive one of three treatments:

1. 2 mA tDCS
2. 1 mA tDCS
3. Sham (placebo) stimulation

The treatment involved 10 sessions over 5 days, with two 20-minute stimulation sessions per day separated by a 20-minute break. This “intensified” protocol aimed to produce stronger and longer-lasting effects.

The researchers assessed OCD symptoms, anxiety, depression, quality of life, cognitive performance, and brain activity before treatment, immediately after, and at a 1-month follow-up.

Key findings

Reduced OCD symptoms

• The 2 mA stimulation significantly reduced OCD symptoms (measured by the Yale-Brown Obsessive Compulsive Scale) immediately after treatment and at the 1-month follow-up
• The 1 mA stimulation reduced symptoms only at the 1-month follow-up
• No significant changes were seen with sham stimulation

Improvements in related symptoms

• The 2 mA stimulation reduced anxiety and depression and improved quality of life
• The 1 mA stimulation reduced depression but did not significantly affect anxiety or quality of life

Enhanced cognitive performance

• Both active stimulation protocols improved response inhibition to some degree
• The 2 mA stimulation also improved working memory performance and reduced attention bias toward OCD-related stimuli

Changes in brain activity

• Both protocols increased alpha wave activity in the brain, which is often reduced in OCD
• The 2 mA stimulation also decreased delta wave activity, which is typically elevated in OCD
• Both protocols increased connectivity between brain regions in higher frequency bands

Conclusions

• Intensified tDCS targeting the prefrontal-supplementary motor network shows promise for reducing OCD symptoms and improving related issues like anxiety and depression
• The higher intensity 2 mA stimulation was more effective overall than 1 mA stimulation
• The treatment was well-tolerated with no serious side effects reported
• Larger studies are needed to further evaluate the effectiveness of this approach

While these results are encouraging, it’s important to note that this was a relatively small study. More research is needed to determine the optimal stimulation parameters and confirm the long-term benefits and safety of this approach. However, this study provides a promising foundation for developing new non-invasive treatments to help people with OCD who don’t respond to current therapies.