Individuals with depression suffer from a number of emotional and physical symptoms. While all depressive symptoms create a heavy burden, symptoms of mental decline and memory loss may be particularly frustrating for the depressed person and ultimately fuel his feelings of worthlessness and hopelessness.
Depression Symptoms
Depression is characterized by a number of emotional and somatic (bodily) symptoms including persistent sad mood, loss of interest in daily activities, fatigue, sleep disturbances, weight loss or gain, and feelings of hopelessness, helplessness and worthlessness. Depressed persons may also experience psychomotor changes in the form of agitation--feeling antsy and irritable--or retardation--a slowing of body movements. Another serious symptom of depression is suicidal thoughts and behaviors. The patient may experience recurrent thoughts about death, thoughts about committing suicide that include the development of a plan, or suicidal gestures or attempts.
Selective Attention and Negative Memories
Depressed individuals may adopt a cognitive style in which they see the world through negative glasses. They attend more to negative events that are consistent with their feelings of sadness and hopelessness. When prompted to recall events, they may be more likely to recall only negative examples. This may be interpreted by the depressed person and her loved ones as a type of memory loss--in effect, a forgetting of all positive memories.
Impaired Cognitive Function
Our cognitive processes rely on the proper functioning of neurotransmitters that facilitate blood flow and communication between brain cells, ultimately keeping our minds chemically balanced and functioning efficiently. Depressed individuals generally have depleted levels of the neurotransmitter serotonin. Low serotonin levels lessen blood flow and brain activity, in addition to decreasing arousal and the ability to experience pleasure in response to stimuli. The consequences of this are seen in the cognitive complaints of depressed people. These complaints typically include trouble concentrating, problems making decisions and organizing thoughts, decreased ability to plan ahead for future events, and problems motivating and initiating behavior.
Brain imaging studies confirm this phenomenon, showing reduced blood flow in the frontal lobe of the brain in depressed persons. The frontal lobe is the area of the brain responsible for attention, initiation, problem-solving, memory, planning, and drive--all traits in which depressed individuals report declines.
The ability to create long-term memories may also be impaired among those who are depressed. This is thought to be due to the depressed person's difficulties concentrating and paying attention. Because they find it difficult to maintain focus on activities, they do not encode events even in short-term memory, which means they never have a chance to become long-term memories.
Fortunately, there is evidence to show that declines in memory are reversible. In the March 2001 "European Archives of Psychiatry and Clinical Neuroscience," an article presents findings from a study in which men who underwent therapy for depression showed improvements in memory test performance (and declines in self-reported memory complaints) in accordance with improved mood. These results offer encouragement about the temporary nature of some depression-related memory loss.
References
- Memory Loss Online: Depression and Memory
- Centre for Neuro Skills: Frontal Lobe
- "European Archives of Psychiatry and Clinical Neuroscience;" Mood improvement reduces memory complaints in depressed patients; Antikainen R et al.; 2001
