What Mechanism in the Brain Causes Depression & Anxiety?

Messengers

The causes of depression and anxiety disorders are not fully known, but it is believed that electrochemical processes in the brain are involved along with the psychological factors. Depression may be involved in an abnormal process delivering certain key neurotransmitters, the chemical messengers in the brain. These neurons regulate mood and other behaviors. Imbalances in the neurotransmitter serotonin, important for feelings of well-being, can trigger depression and other mood disorders, according to HealthCentral.com. Corticotrophin-releasing factor is a stress hormone and neurotransmitter that appears to interact with serotonin and has been detected in patients with depression or anxiety. Neurotransmitters containing adrenaline and dopamine that deal with stress may also be involved. It is believed these chemical messengers are disturbed in the process because of other factors that include abnormalities in the brain, sleep disorders or genetic susceptibility.

Regions

Specific areas of the brain may be linked to anxiety and depression, according to the Lundbeck Institute, an international forum and information center for central nervous system disorders. The limbic system in the lower center of the brain is involved in memories and emotions. It is thought to play a major role in processing anxiety-related information. The hippocampus, a component of the limbic system and important in forming memories, appears to be smaller in some people with post-traumatic stress disorder. There may be a degeneration of cells in that part of the brain that cause stress-induced chemicals. The hypothalamus, which is involved in sleeping and waking states, may be involved in anxiety disorders. People with obsessive-compulsive disorder have been found to have increased activity in areas of the forebrain, the largest portion of the brain that deals with sensory and motor function.

Antidepressants

The role of serotonin inhibitors in antidepressants has been shown to relieve anxiety disorders. Enhancing serotonin concentration in the brain increases anxiety, but a reduction in serotonin concentrations reduces anxiety, according to the Lundbeck Institute. But, there are many other factors involved in the brain. Defective genes that regulate serotonin have been linked to depression. Scientists hope that understanding more about gene mutations will help them regulate neurotransmitters so they may be able to have better predictions and treatment for people suffering from depression and anxiety.