For additional terms and definitions, visit the CTN CIHR Candian HIV Trials Network ‘s website.

Computerized tool to measure cognitive ability.

To give the brain the best chance for longevity and overall health. A healthy brain can learn, think, organize and store ideas, remember, be strategic, make decisions and multi-task. It can feel a range of emotions, express itself and be intuitive. It controls a person’s ability to move at will, walk, talk, breathe, swallow and sleep.

In science, cognition is a group of mental processes that includes attention, memory, producing and understanding language, learning,reasoning, problem solving, and decision making.

Cognitive abilities are the brain-based skills we need to carry out any task from the simplest to the most complex. They have more to do with the mechanisms of how we learn, remember, problem-solve, and pay attention rather than with any actual knowledge.

A cognitive assessment is an examination conducted to determine someone’s level of cognitive function.

Cognitive impairment is when a person has trouble remembering, learning new things, concentrating, or making decisions that affect their everyday life. Cognitive impairment ranges from mild to severe. With mild impairment, people may begin to notice changes in cognitive functions, but still be able to do their everyday activities. Severe levels of impairment can lead to losing the ability to understand the meaning or importance of something and the ability to talk or write, resulting in the inability to live independently.

Variety of brain exercises designed to help work out specific cognitive abilities. The principle underlying cognitive training is to help improve “core” abilities, such as attention, memory, problem-solving.

A Cohort is any designated group of people who are followed or traced over a period of time. For example, all of the students in a class, everyone born in Canada in 1984 or a group of individuals participating in a study.

A Cohort study is an observational study in which a group of subjects are followed over time. Information is collected about the subjects’ characteristics and exposures and then they are followed to see which subjects experience the health outcome of interest. For example, the outcome of interest could be a heart attack, cancer or liver disease. The number of people who experienced the outcome is compared between those who were exposed to a factor and those who were not exposed. For example, the exposure of interest may be alcohol, a medication or high cholesterol. It is very important that the investigator is not involved in choosing whether or not a subject is exposed, and instead only observes what happens.

Psychiatric Diagnoses are categorized by the Diagnostic and Statistical Manual of Mental Disorders, 4th. Edition. Better known as the DSM-IV, the manual is published by the American Psychiatric Association and covers all mental health disorders for both children and adults. It also lists known causes of these disorders, statistics in terms of gender, age at onset, and prognosis as well as some research concerning the optimal treatment approaches.

Hepatitis C is an RNA virus that is transmitted through blood and attacks the liver. Those who are infected often do not show symptoms for a long time. It is possible for the body to clear the virus however, those who have a weakened immune system are less likely to do so. Chronic infection with HCV may lead to scarring of the liver, liver cancer or liver failure.

Highly active antiretroviral therapy was introduced in the mid-1990’s and consists of a combination of at least 3 antiretroviral medications; 2 nucleoside reverse transcriptase inhibitors (NRTIs) plus either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI).

HIV Associated Neurocognitive Disorders (HAND) can occur when HIV enters the nervous system and impacts the health of nerve cells. This, in turn, can impair the activity of nerves involved in: attention, memory, language, problem solving and decision making.

Human immunodeficiency virus is a retrovirus that is transmitted through blood, semen, vaginal fluids and breast milk. HIV attacks the immune system and causes Acquired Immune Deficiency Syndrome (AIDS).

Gold standard in treatment for certain types of hepatitis B and C.

In a controlled observational cohort study, two groups of subjects are selected from two populations that (hopefully) differ in only one characteristic at the start. The groups of subjects are studied for a specific period and contrasted at the end of the study period.

Scale used to diagnose HIV-associated neurocognitive disorders (HAND), which contains gradations that range from minor cognitive disturbance to profound and incapacitating disorders.

The brain’s ability to reorganize itself by forming new connections throughout life.

An Opportunistic infection or disease occurs when pathogens that are normally fought off by a person’s immune system cause illness because the person’s defenses are weakened by such factors as poor nutrition or infection by HIV.