9781422280362

Depression, Anxiety, and Bipolar Disorders

page 15 shows just some of the risk factors that can increase the likelihood of depression, anxiety, or both during adolescence. Brain chemicals called neurotransmitters are important contributors to depression and other mental disorders. Neurotransmitters carry signals between brain cells and are involved in many functions in the body, including mood, appetite, learning, and memory. If something goes wrong with them, there can be wide-ranging effects. For example, the neurotransmitters called serotonin and glutamate have been implicated in depression, while serotonin, gamma- aminobutyric acid (usually called GABA), dopamine, and epinephrine may play a role in anxiety disorders. the original neuron for reuse, in a process known as reuptake . Mental illnesses are thought to involve imbalances in the levels of neurotransmitters in the brain. For example, the amount of serotonin may be abnormally low in people with depression. The antidepressants known as selective serotonin reuptake inhibitors (SSRIs) work by preventing reuptake of serotonin so that levels are boosted. Chemical Signals Within the brain and nervous system, billions of cells called neurons are constantly sending messages back and forth, coordinating all the different activities your body needs to survive. They do this mostly by releasing chemical neurotransmitters, which travel from one neuron to another at sites called synapses . After crossing a synapse, each neurotransmitter attaches to a specific receptor on the postsynaptic neuron, like a key fitting into a lock. Once a neurotransmitter has successfully bound to a receptor, it is released. It then returns to the synaptic space, where it is either broken apart or transported back into

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