There are many different types of depression and I think it depends on what type of depression, but one of the most powerful remedies for depression is to think about death. We need strong meditation about the uncertainty of the time of death—it can happen today, even within this hour. This is a very powerful meditation that is very good at these times, as it immediately cuts depression.
When we have depression, we can also think about the numberless other sentient beings who have depression, and we can think, “As I've been praying, I have received all sentient beings' suffering, particularly depression. I have received it within me and I am experiencing this depression on behalf of all other sentient beings.” Think the depression that we are experiencing is not our depression, but the depression of all sentient beings.
This is extremely beneficial, because we are utilizing the depression as a path to achieving full enlightenment. We are making the depression a medicine and we are using the depression as a path to enlightenment. Depression becomes the means, like tantric practice, to purify many eons of negative karma and to accumulate infinite merit, to achieve enlightenment more quickly. The experience of depression becomes extremely beneficial and useful for the happiness of all sentient beings. So that means, naturally, we are using our depression to achieve the best happiness for ourselves, the highest enlightenment.
The other powerful technique is to think the depression is given to us by the ego. Depression is a causative phenomenon, so it has a cause. There could be external conditions, but the main cause is the inner cause, which is our own mind. That is our past karma, the negative intention—having done something that disturbed others’ minds, made others’ minds unhappy, and especially disturbed holy beings’ minds.
The cause of depression is mentioned in the teaching of the Wheel of Sharp Weapons, an extensive teaching that is not only about bodhicitta practice to destroy the ego, but is also an extensive meditation on karma. It mentions degenerating our samaya by displeasing the holy mind of the virtuous friend and so forth, in the past.
This negative karma and negative intention happened due to the ego, the self-centered mind. Therefore, this depression and harm is given to us by the ego. When we know who caused the depression, then without delaying even a second, we can immediately return the depression back to the ego and destroy it. Let the ego have it! Rather than taking the depression on ourselves, we just give it back and destroy the ego. In this way, we use the depression to destroy the ego. If we are able to destroy the ego, if there is no ego—no self-centered substantive mind— it means we have bodhicitta, cherishing other sentient beings. This is how we use depression to develop bodhicitta, the door of the Mahayana path to enlightenment, to be able to liberate all sentient beings from all their suffering and lead them to enlightenment. So, the benefits are infinite.
The other technique for depression is to reflect on the buddha nature in our mental continuum. We have the potential to actualize the whole path to enlightenment—all the realizations, all the infinite qualities of Buddha's holy body, holy speech and holy mind. All the potential is there. We just need to purify our minds so that all the realizations, all the qualities of Buddha manifest and come out. Reflecting on buddha nature is another extremely beneficial remedy for depression, depending on what type of depression we experience.