I take omega-3 as fish oil and it improves my mood. If you end up taking it - I suggest not buying the cheapest fish oil. Instead you google to find a brand that's high quality.

Omega-3 fatty acids for mood disorders - Harvard Health

How might omega-3s improve depression?

Different mechanisms of action have been proposed. For example, omega-3s can easily travel through the brain cell membrane and interact with mood-related molecules inside the brain. They also have anti-inflammatory actions that may help relieve depression.

More than 30 clinical trials have tested different omega-3 preparations in people with depression. Most studies have used omega-3s as add-on therapy for people who are taking prescription antidepressants with limited or no benefit. Fewer studies have examined omega-3 therapy alone. Clinical trials typically use EPA alone or a combination of EPA plus DHA, at doses from 0.5 to 1 gram per day to 6 to 10 grams per day. To give some perspective, 1 gram per day would correspond to eating three salmon meals per week.

Meta-analyses (research that combines and analyzes results of multiple studies) generally suggest that the omega-3s are effective, but the findings are not unanimous because of variability between doses, ratios of EPA to DHA, and other study design issues. The most effective preparations appear to have at least 60% EPA relative to DHA. While DHA is thought to be less effective as an antidepressant, it may have protective effects against suicide. Recent work at Massachusetts General Hospital and Emory University suggests that depressed individuals who are overweight and have elevated inflammatory activity may be particularly good candidates for EPA treatment.

Children and adolescents with depression may also benefit from omega-3 supplementation. At Harvard, there is a large study underway examining whether omega-3 supplementation (alone or in combination with vitamin D) can prevent depression in healthy older adults.