Recently it has been proven that allergies to certain foods may cause or aggravate conditions such as chronic depression. See an allergist to determine if this may be the actual root of your problem. Low levels of B6 and B complex have been linked to depression, as a shortage of either or both severely affects the nerves. Exercise regularly and get outside in the sunshine. Exercise helps the body to eliminate toxins, and the adrenaline you get from even mild exercise can lessen the severity of an attack of depression.
Sunlight warms the body and the soul.
Your body can't make use of vitamin D without it, and a deficiency of this vitamin has been linked to some forms of depression. If you are taking something that keeps you out of the direct sun, sit in a shaded area outside for a few minutes each day. You will notice the difference. Inside, try using full-spectrum lighting to help synthesize vitamin D and uplift your spirits. There are herbal therapies that can help you manage chronic depression.