Dopamine is a natural chemical substance that is produced from the amino acid tyrosine by a mid-brain structure called the substantia nigra. As a neurotransmitter, dopamine transmits chemical signals from the dopamine-containing neurons to target cells that contain dopamine receptors.

The Great Depression, which generally is considered to have begun with the stock market crash in October 1929, changed the way America worked. At the end of the Roaring Twenties when the stock market and the economy soared, the crash appeared inevitable in retrospect.

Everyone feels anxiety at some point in his life. Unfortunately, for many, anxiety can become crippling, such as seen with anxiety disorders.

Diagnosing children with attention deficit hyperactivity disorder can be difficult depending on the age of the child. The characteristic symptoms of the disorder, inattention, hyperactive behavior, and impulsivity, are more normative in young children than in school-age children.

Overeaters anonymous, or OA, is a group movement in which those who have a compulsive eating disorder offer each other support and fellowship with the goal of not overeating. OA doesn't promote any specific diet approach; the basis of the program is abstaining from the behavior of compulsive eating.

Anxiety disorders affect more than 18 percent of adults in the U.S. in a given year, according to the National Institute of Mental Health. These disorders cause symptoms that can make daily activities difficult. Medications are sometimes used to help alleviate some symptoms of an anxiety disorder.

The subtle cues of dating and sexual relationships may be difficult for people with Asperger's to navigate. The syndrome is commonly known by a lack of social awareness or skills, communication difficulties, obsession with a particular topic or subject and poor coordination.

Personality characteristics have been a common focal point in psychological research studies through the years, and there has always been discussion as to how many family influences play a role in personality development.

Genetic diseases result from mutations or abnormalities on chromosomes or genes. Some ethnic groups are at higher risk for some genetic diseases than others, but the diseases can occur in any group, according to the Genetic Disease Foundation.

If you are a nail-biter, a hair-twister, or a forehead-rubber, or if you unnecessarily worry or feel fatigued, restless or lightheaded, the National Institute of Mental Health and researchers at North Dakota and Michigan State universities suggest you may suffer from anxiety.

Agitated depression is unique in that it does not consist of the typical depression symptoms of fatigue and sadness. This type of clinical depression can consist of feelings of irritation, restlessness, anger, insomnia, fidgeting, or racing thoughts. According to Survivingdepression.

Ashwagandha, or "Winter Cherry," is an adaptogen herb commonly used in ayurvedic medicine, a holistic form of medicine that originated from India. Ashwagandha appears to contain restorative and rejuvenating qualities as well as anti-inflammatory properties.