Inhalation of essential oils is the best way to assist with emotional problems such as stress, anxiety and depression as it reaches the limbic system in the brain quickly. The forebrain is the largest portion of the brain and consists of the two cerebral hemispheres (left brain, right brain) and also contains the limbic system. The limbic system consists of many parts. These parts control integration of information from our senses, voluntary movement, higher abstract thought, logic, speech and emotions. The limbic system establishes emotional states (happiness, fear, anger) and links to both conscious responses such as movement, as well as autonomic (unconscious) functions including hormones. It also facilitates memory storage and retrieval.