The hippocampus of the brain is responsible for short-term memory. When a person is depressed the hormone cortisol enters the bloodstream and shrinks certain areas of the brain — one of which is the hippocampus. Depressed people lose their ability to concentrate, and have difficulty remembering new information. Without short-term memory the brain is not able to process long-term memories.
Research has shown that depressed people only remember negative memories, which leads them to prolong their depression. It also affects executive function. A person with major depression becomes forgetful, is not able to organize thoughts, can’t sleep regularly, and has trouble making decisions. They can’t start tasks, and if they do they have trouble finishing them. That is why you often hear of depressed people sitting in front of the television set 24/7. Depression is an extremely misunderstood mental condition, and the effects can be devastating for the victim, and the people around them.
Those who suffer from depression need to understand a bit about it. It is a mood disorder that can affect everyone in a different way, and for all sorts of reasons. Excess chemicals are being produced in the brain (neurotransmitters) that set off a chemical imbalance. This imbalance effects the connections between the brain and the body. Some people have a genetic predisposition to mood disorders, and some experience it as a result of drugs or medication. Most already have low self-esteem, or are normally pessimistic, so a tragedy such as a divorce, death of a loved one, or loss of a job, could set off depression or put someone into a deeper one.
If short-term memory is affected it would stand to reason that memories cannot be passed on to long-term memories. “It really comes down to a lack of attention and concentration,” explains Constantine Lyketsos, MD, director of neuropsychiatry at the Johns Hopkins School of Medicine. “For example, a depressed man agrees to meet a spouse or friend at a certain address. An hour later, he realizes he has “forgotten” the address. But perhaps due to a lack of attention and concentration-a hallmark of the depressed mental state-he never really formed an enduring memory of the address in the first place.”
One recent Finnish study observed 174 adults with major depression for six months. At the beginning of the study the patients were given several neuropsychological memory tests, including the ability to repeat short stories or lists from memory, and they performed poorly on these tests. The subjects were given treatment, including medication and/or psychotherapy, and at the end of the study the patients who had reduced their depression also reported to have less problems with their memory.
Psychotherapy and medication can help to reduce the symptoms, and depression is highly treatable, if the subject wants treatment. Many won’t admit they have a problem. Unfortunately, some anti-depressant medications can put patients into a “brain fog,” making memory problems worse. The medications will then need to be adjusted to another type with different side effects.
Scientists are probing the connection between depression and memory with the use of brain-imaging techniques. They are hoping to see ways they can understand the connections between mind, mood and memory in order to improve treatments.
Depression leaves scars, and some people suffer for years. It affects their ability to sleep normally, their sex drives and their ability to enjoy simple things. Memory is the biggest casualty, but other functions are also affected. If you know of anyone who is depressed, get him or her help immediately.
From the desk of Ron White
Discovery — How Can Depression Affect Your Short-Term Memory? http://curiosity.discovery.com/question/depression-affect-short-memory
Memory Loss and the Brain — Depression and Memory: http://www.memorylossonline.com/summer2001/depression.html