Can Fish Oil Help Treat Depression in Young People?

What you need to know

• This large clinical trial found that fish oil supplements did not improve depression symptoms in young people aged 15-25 compared to placebo.
• All participants received standard mental health care, which may have been effective enough that fish oil provided no additional benefit.
• Fish oil supplements were safe and well-tolerated, with few side effects reported.

Background

Depression is the leading cause of disability in young people worldwide. While treatments like antidepressant medications and psychotherapy are available, they don’t work for everyone. There’s been interest in whether omega-3 fatty acids, found in fish oil, could help treat depression. Some smaller studies have suggested omega-3s might be beneficial for depression in adults. However, there hasn’t been much research on whether they help young people with depression.

This study aimed to determine if fish oil supplements could improve depression symptoms in young people aged 15-25 who were already receiving mental health care. The researchers conducted a large clinical trial across three cities in Australia to test this.

How the study was conducted

The study enrolled 233 young people aged 15-25 who were seeking care for depression at youth mental health clinics. To be included, participants had to have moderate to severe depression symptoms.

Participants were randomly assigned to receive either:

1. Fish oil supplements (containing omega-3 fatty acids)
2. Placebo supplements (containing no active ingredients)

Neither the participants nor the researchers knew who was receiving which treatment. This is called a “double-blind” study design.

All participants also received standard mental health care, including cognitive behavioral therapy sessions with trained therapists. The study lasted 12 weeks.

The main outcome the researchers measured was change in depression symptoms using a standardized rating scale called the QIDS-A17-C. They also looked at other measures of mental health and functioning.

To make sure participants were actually taking the supplements, the researchers measured omega-3 fatty acid levels in participants’ blood before and after the study.

What the study found

The key findings were:

• Depression symptoms improved significantly in both groups over the 12 weeks.
• There was no significant difference in improvement between the fish oil and placebo groups.
• The fish oil group did show increases in omega-3 levels in their blood, confirming they were taking the supplements.
• Fish oil supplements were safe, with few side effects reported.

Specifically, the average decrease in depression scores was:

• 5.6 points in the fish oil group
• 5.8 points in the placebo group

This small difference of 0.2 points was not statistically significant, meaning it could easily have occurred by chance.

The researchers also looked at whether fish oil might work better for certain subgroups, such as those with more severe depression or lower omega-3 levels to start with. However, they didn’t find any subgroups that benefited more from fish oil than placebo.

Why fish oil may not have shown a benefit

There are a few potential reasons why this study didn’t find a benefit from fish oil supplements:

1. All participants received standard mental health care, including therapy sessions. This care may have been effective enough that fish oil couldn’t provide additional benefit beyond it.

2. The placebo effect may be stronger in young people. Previous research has shown that young people often show large improvements even when given inactive placebo treatments for depression. This makes it harder to detect effects of active treatments.

3. The omega-3 levels of participants may not have been low enough at the start for supplements to make a difference. The average omega-3 index (a measure of omega-3 levels) was 4.7%, which is not considered deficient.

4. The dose or duration of fish oil supplementation may not have been enough. However, the dose used was based on previous positive studies in adults, and blood tests confirmed omega-3 levels did increase in the fish oil group.

5. Fish oil supplements may simply not be effective for treating depression in this age group, despite some evidence of benefit in adults.

Strengths and limitations

Strengths of this study include:

• Large sample size (233 participants)
• Rigorous design (randomized, double-blind, placebo-controlled)
• Conducted across multiple sites
• Measured blood levels of omega-3s to confirm supplement intake
• Included only participants with diagnosed major depression

Limitations to consider:

• The study only lasted 12 weeks - longer-term effects are unknown
• All participants received mental health care alongside supplements, which may have masked potential benefits of fish oil alone
• The results may not apply to young people not already receiving mental health care

Conclusions

• Fish oil supplements did not improve depression symptoms more than placebo in young people aged 15-25 who were already receiving mental health care.
• The supplements were safe and well-tolerated.
• Based on this study, fish oil cannot be recommended as an add-on treatment for depression in young people receiving standard mental health care.
• More research is needed to determine if fish oil might be beneficial in other circumstances, such as for preventing depression or in young people not receiving other treatments.

While this study didn’t find a benefit, it’s important to remember that depression treatment often requires a personalized approach. What works for one person may not work for another. Young people experiencing depression should work with mental health professionals to find the most effective treatment plan for their individual needs.