is a disorder marked by altered mood, particularly sadness
and apathy. Depression is one of the most common mental illnesses;
some researchers estimate that 3-5% of the world's population
experiences depression on any given day.
Everyone experiences feelings of sadness and depression from
time to time; depression becomes clinically significant ("clinical
depression" or "major depression") when it
occurs over a period of days or weeks and includes several
of the following: loss of self-worth or feelings of excessive
guilt, loss of interest in usually pleasurable outlets such
as hobbies, food, sex, entertainment, and friends, loss of
energy, sleeping disorders (sleeping too much or too little),
and recurrent suicidal thoughts or attempts.
Clinical depression may be treated in several ways, including
psychotherapy, antidepressent medication, and electroconvulsive
Clinical depression may result from imbalances in brain chemicals
normally associated with signaling reward or pleasure, such
as serotonin and dopamine. Depression may also result from
several neurological disorders, including Alzheimer's disease
and Parkinson's disease. Depression is also a common complaint
among otherwise healthy elderly individuals.
Because a depressed individual will find it hard to concentrate,
there may be memory problems, because the ability to learn
and remember new information depends on the ability to pay
attention to that information in the first place.
Article : "DEPRESSION AND MEMORY"
by Catherine E. Myers. Copyright © 2006 Memory Loss and the Brain