Since the root cause of depression is unknown, there is no reliable way to prevent it from occurring. Since you cannot do anything to change your genetics and science is still learning about ways to influence brain biochemistry, that leaves the environment as the one factor in depression that you can control. Taking steps to limit stress in your life or learning new strategies for coping with stress and trauma may help lower the chances of your becoming depressed. Building a support system of friends and relatives that you can rely on during a crisis may also help. Getting treatment as early as possible after symptoms appear can help reduce the impact of a depressive episode. Finally, if you have been depressed in the past, maintenance treatment in the form of medication or psychotherapy may help lower the chances of depressive symptoms recurring.