COGA's aim is to identify the genes involved in alcoholism. There is a large body of twin-studies and adoption-studies that show that alcoholism is inherited. COGA is trying to determine more specifically how it is inherited and what genes are involved. There is no one gene that controls alcoholism, rather it is polygenetically controlled. That means, there are several different genes that influence risk factors involved in alcoholism. Examples of these risk factors include one's level of response to alcohol, a person's neuroelectrochemistry, and other psychiatric disorders, such as Antisocial Personality Disorder or clinical depression.
COGA researchers will interview subjects using the SSAGA, or Semi-Structured Assessment for the Genetics of Alcoholism, specifically created for the COGA project. Each subject is asked to participate in the SSAGA, with different versions for adolescents and for parents being interviewed about their children. The SSAGA is a polydiagnostic psychiatric interview that will cover any drug or alcohol use as well as any emotional and/or medical problems the subject may have experienced. The SSAGA is designed to use diagnostic criterion from the DSM III-R, DSM IV, and ICD-10.
COGA requests that their subjects provide a blood sample, which is then processed and examined at Rutgers University. Genes not only carry information about eye and skin color, but also carry vulnerability to specific diseases, and probably cause a susceptibility to alcoholism as well. COGA is attempting to find those chromosomes involved in alcoholism and have located specific loci thought to be involved.
The brain wave is called an event-related potential (ERP) and is similar to an EEG. Brainwaves are monitored in a non-invasive procedure that involves placing a cap on the subject's head, similar to a bathing cap. This cap will monitor the brain's natural electrical activity and will record the brain's response when the subject is presented with various stimuli. Subjects respond to computer programs on a screen in front of them that flash various stimuli on the screen. After a significant event, or an important stimuli to which the subject is instructed to respond, there is an increase in electrical activity. COGA is investigating the P3, or P300, wavelength that occurs approximately 300 ms after the stimuli presentation. Varying amplitudes of the wave have different behavioral implications. The amplitude is fairly consistent throughout families and steady across time, suggesting an inherited component, as opposed to an environmental component.
Subject's confidentiality is important to COGA. Subjects' names are never connected with the information they give. Rather, an ID number is assigned to them. COGA has also received the Confidentiality Certificate from the Department of Health and Human Services (DHHS) to protect researchers from being forced, even by court subpoena, to identify you. The Certificate adds protection only for the research information and does not mean the Secretary of DHHS approves or disapproves of the project.