Amino acid: An organic compound which is a basic constituent of a protein.

Anxiety Disorders: Anxiety disorders cause intense feelings of anxiety and tension when there is no real danger. 

Attention Deficit Hyperactivity Disorder (ADHD): A common developmental and behavioral disorder. It is characterized by poor concentration, distractibility, hyperactivity and impulsiveness that are inappropriate for the child's age. Children and adults with ADHD are easily distracted by sights and sounds in their environment, cannot concentrate for long periods of time, are restless and impulsive, or have a tendency to daydream and be slow to complete tasks. 

Bipolar Disorder (manic depressive disorder): A mental illness that causes people to have severe high and low moods. People with this illness switch from feeling overly happy and joyful (or irritable) to feeling very sad and hopeless (or extreme happiness). In between mood swings a person's moods may be normal.

Depression: A clinical mood disorder associated with low mood or loss of interest and other symptoms that prevents a person from leading a normal life. Types of depression include: Major depression, bipolar depression, dysthymia and seasonal depression (seasonal affective disorder).

Dysthymia: a chronic (ongoing), low-grade depression that often begins in childhood or adolescence and may last for many years in adulthood if left untreated. 

Manic depression: An abnormal mental condition characterized by an excessive elevation of mood, exagerated activity and disorganization, which alternates with depressed feelings. 

Monoamine Oxidase Inhibitors (MAOIs): A group of medicines sometimes prescribed to treat severe depression. MAOIs increase the concentration of chemicals responsible for transmitting information between nerves in particular regions of the brain, which may lead to increased mental functioning. 

Neurotransmitters: Chemical messengers that carry messages or signals between the various nerves in the brain; the neurotransmitters serotonin, dopamine, and norepinephrine are believed to be the chemical messengers responsible for moods and emotions.

Obsessive-Compulsive Disorder (OCD): One of the anxiety disorders this is a potentially disabling condition that can persist throughout a person's life. The individual who suffers from OCD becomes trapped in a pattern of repetitive thoughts and behaviors that are senseless and distressing but extremely difficult to overcome.

Panic Attack / Panic Disorders: A stress-related, brief feeling of intense fear and impending doom or death, accompanied by intense physiological symptoms such as rapid breathing and pulse, sweaty palms, smothering sensations, shortness of breath, choking sensations and dizziness. In general, the attacks last 15 to 30 minutes.

Postpartum Depression: Postpartum depression is a complex mix of physical, emotional and behavioral changes that occur in a mother after giving birth. It is a serious condition, affecting about 10% of new mothers. Symptoms range from mild to severe depression and may appear within days of delivery or gradually, perhaps up to a year later. Symptoms may last from a few weeks to a year.

Psychiatrists: Physicians who specialize in treating mental, emotional or behavioral disorders. They have completed four years of study in an accredited medical school in combination with four years of postgraduate training in a certain area of psychiatry. They are doctors who can prescribe medications.

Psychologists: Specialists who concentrate in the science of the mind and behavior. They usually have a doctoral degree and receive additional training to work with patients. Psychologists are not medical doctors and cannot prescribe medication, but do perform evaluations and use psychotherapy.

Psychosis: An illness that prevents people from being able to distinguish between the real world and the imaginary world. Symptoms include hallucinations (seeing or hearing things that aren't really there), delusions (false beliefs), irrational thoughts and fears. 

Schizophrenia: A mental illness in which the person suffers from distorted thinking, hallucinations and a reduced ability to feel normal emotions. 

Seasonal affective disorder (SAD): A form of depression thought to be triggered by a decrease in exposure to sunlight. 

Selective serotonin reuptake inhibitors (SSRIs): A class of antidepressant drugs that help to increase serotonin, a chemical responsible for communication between nerves in the brain. Representative drugs include fluoxetine (Prozac), paroxetine (Paril), sertraline (Zoloft), citalopram (Celexa), estialapram (Lexapro) and fluvoxamine (Luvox). Serotonin: A neurotransmitter and hormone. Deficiency of serotonin in the brain is theorized to cause symptoms of depressed mood, anxiety, panic or obsessions and compulsions.

SSRI - Selective Serotonin Reuptake Inhibitor: A class of antidepressant medications.

Tricyclic Antidepressants: (Commonly called TCAs). An old class of drugs prescribed for depression disorder. (e.g. imipramine (Tofranil), amitriptyline (Elavil) and nortriptyline (Pamelor)).