It’s believed that two parts of the brain are responsible for anxiety and depression: the amygdala and the hippocampus. The dorsomedial thalamus may be involved in depression. It’s not really known what causes anxiety or depression, but there may be a predisposition for anxiety or depression that runs in families and is triggered by trauma or negative life circumstances. In the late fall season, depression becomes more common. It’s also common for anxiety and depression to exacerbate each other, and symptoms can be quite severe. It’s definitely important to seek professional care if you suspect you or a loved one may be dealing with one issue or the other, or both.