Can Brain Stimulation Help Older Adults with Depression When Medications Don't Work?

What you need to know

• Brain stimulation treatments called rTMS and TBS can help treat depression in older adults when medications don’t work
• These treatments were more effective for people who had tried fewer depression medications previously
• Using brain stimulation earlier in treatment may lead to better outcomes for older adults with depression

Understanding Depression Treatment in Older Adults

Depression is a common and serious mental health condition that can significantly impact quality of life, especially for older adults. While antidepressant medications are often the first-line treatment, they don’t work for everyone. When multiple medication trials fail to provide relief, a person is considered to have treatment-resistant depression. This is particularly prevalent in older adults.

Researchers are always looking for new ways to help people with treatment-resistant depression. One promising approach is called repetitive transcranial magnetic stimulation (rTMS). This non-invasive brain stimulation technique uses magnetic pulses to activate specific areas of the brain involved in mood regulation. A newer form of rTMS, called theta burst stimulation (TBS), can deliver the treatment in less time.

The FOUR-D Study: Comparing Brain Stimulation Treatments

To better understand how these brain stimulation treatments work for older adults with depression, researchers conducted a study called FOUR-D. This study compared two types of brain stimulation:

1. Standard bilateral rTMS: This involves stimulating two areas of the brain - applying low frequency pulses to the right side followed by high frequency pulses to the left side.

2. Sequential bilateral TBS: This uses a different pattern of magnetic pulses, also targeting both sides of the brain in sequence.

The study included 172 adults aged 60 and older with depression who hadn’t responded well to at least one antidepressant medication trial. Participants received either rTMS or TBS treatment daily for 4-6 weeks.

How Prior Medication Use Affected Treatment Outcomes

One of the key questions researchers wanted to answer was: Does the number of previous medication trials a person has tried affect how well they respond to brain stimulation treatment?

To investigate this, they divided participants into three groups based on how many adequate trials of antidepressant medications they had previously tried:

1. One or fewer trials
2. Two trials
3. Three or more trials

Here’s what they found:

• 43.9% of people who had tried one or fewer medication trials achieved remission (significant improvement in depression symptoms)
• 26.5% of those who had tried two medication trials achieved remission
• 24.6% of those who had tried three or more medication trials achieved remission

This difference was statistically significant, meaning it’s unlikely to have occurred by chance. The results suggest that brain stimulation treatments tend to be more effective for people who have tried fewer antidepressant medications previously.

Interestingly, there was no significant difference in remission rates between the standard rTMS and the newer TBS treatment. This suggests that both forms of brain stimulation are similarly effective for treating depression in older adults.

The Importance of Treatment History

These findings highlight the importance of considering a person’s treatment history when deciding on the best approach for depression. The study suggests that using brain stimulation treatments earlier in the course of depression treatment - perhaps after just one unsuccessful medication trial - might lead to better outcomes.

This doesn’t mean that brain stimulation won’t work for people who have tried many medications. Some people in the study did achieve remission even after trying three or more medication trials. However, the chances of success appear to be higher when brain stimulation is used earlier in treatment.

Implications for Depression Treatment

The results of this study have several important implications for how we approach depression treatment in older adults:

1. Early consideration of brain stimulation: Doctors might want to consider rTMS or TBS as an option sooner for older adults with depression, rather than trying multiple medications first.

2. Thorough treatment history: It’s crucial for healthcare providers to get a detailed history of what treatments a person has tried before. This information can help guide decisions about whether brain stimulation might be a good option.

3. Equal effectiveness of rTMS and TBS: Since both types of brain stimulation showed similar effectiveness, the choice between them might depend on other factors like availability or treatment duration (TBS sessions are shorter).

4. Hope for treatment-resistant depression: Even though the success rates were lower for people who had tried more medications, some still benefited from brain stimulation. This offers hope for people with highly treatment-resistant depression.

Understanding Brain Stimulation Treatments

For those unfamiliar with rTMS and TBS, it’s helpful to understand a bit more about how these treatments work:

• Both use magnetic pulses to stimulate specific areas of the brain associated with mood regulation.
• The treatments are non-invasive, meaning they don’t require surgery or implants.
• Sessions typically last about 30-40 minutes for standard rTMS, or 3-5 minutes for TBS.
• Treatment courses usually involve daily sessions for 4-6 weeks.
• Side effects are generally mild and can include headache or scalp discomfort.

Unlike medications that affect the whole body, these brain stimulation treatments can target specific brain regions more directly. This might explain why they can sometimes help when medications haven’t worked.

Limitations and Future Research

While this study provides valuable insights, it’s important to note some limitations:

• The study didn’t look at how long people had been depressed, which could also affect treatment outcomes.
• People who had tried more medications were more likely to be on multiple psychiatric drugs during the study, which might have influenced the results.

Future research could help clarify these points and further refine our understanding of when and for whom brain stimulation treatments work best.

Conclusions

• Brain stimulation treatments like rTMS and TBS can be effective for treating depression in older adults, even when medications haven’t worked.
• These treatments tend to be more effective when used earlier in the course of depression treatment, after fewer medication trials.
• Both standard rTMS and the newer TBS treatment appear to be equally effective.
• Consider discussing brain stimulation options with a healthcare provider if you or a loved one are struggling with depression that hasn’t improved with medication.