Clinical Depression Causes Early Malfunctions In The Brain’s Pleasure Center, as bad as smoking for increasing mortality risk

Photo illustration by Mindy Ricketts

Clinically depressed individuals are less capable of finding pleasure in activities they previously enjoyed, a recent study has proven. Research featured in the August 26 issue of the NeuroReport shows reduced brain function in the reward center of the brain in depressed individuals, when compared to healthy subjects.

The study was conducted by Dr. Elizabeth Osuch, a researcher at the Lawson Health Research Institute, and is the first scientific publication of data obtained by the newly developed First Episode Mood & Anxiety Program (FEMAP) research arm at the London Health Sciences Centre in Ontario, Canada.

To investigate the effects of depression on brain activity, Dr. Osuch and her team asked 15 healthy subjects and 16 recently depressed subjects to provide a list of their favorite music as well as identify music that they neither liked nor disliked (neutral music). The subjects then listened to their musical selections for three minutes while a functional magnetic resonance imaging (fMRI) scanner measured the neural activity in their brain.

The researchers found that the healthy subjects showed more brain activity in specific regions when they listed to their favorite music compared to the depressed subjects. More specifically, several regions of the brain that are associated with reward processing were shown to be less activated in the depressed individuals, suggesting that even the most basic capacity of enjoyment seems to be malfunctioning in this area of the brain in those who have depression. This was true in spite of no difference in how enjoyable the two groups rated listening to the music in the scanner.

“Our results revealed significant responses within the areas of the brain that are associated with reward processing in healthy individuals. They also showed significant deficits in these neurophysiological responses in recently depressed subjects compared to the healthy subjects,” explains Dr. Osuch. “It is known that depressed individuals experience anhedonia—a loss of enjoyment in previously pleasurable activities. The study results show that for recently depressed individuals this loss of enjoyment is linked to very specific parts of the brain which are involved with experiencing pleasure. If we can target these areas of the brain through treatment, we have the potential to treat depression earlier, right at the source.”

Depression as bad as smoking for increasing mortality risk

Depression increases your risk of dying as much as smoking, according to a new study published in the August issue of the British Journal of Psychiatry. This was the first large (61, 349 surveyed subjects), comprehensive study that looked at the association between depression and mortality. The researchers came to the surprising conclusion that depression was comparable in strength to smoking as a risk factor for depression.
They found that depression had this strong association with mortality even when taking health status and other confounding factors into account. And the depression did not have to be at a severe level in order to be associated with mortality at the same strength as smoking.
After controlling for physical symptoms and diagnosed health conditions, and after adjusting for age, sex, alcohol problems, educational level, socioeconomic status, body mass index, blood pressure, and cholesterol level, depression was strongly and inexplicably associated with mortality.
Even taking other potential confounding factors into account, the lead author, Arnstein Mykletun, PhD, from the University of Bergen, Norway, gave a “conservative” estimate that depression can account for a 40% increase in the risk of mortality. A less conservative estimate that adjusts for more confounding factors, he said, would be closer to a 60% increase.
Depression is often not taken as seriously as other illnesses and is undertreated. However, research has now firmly established that depression is a disease affecting not just the brain but multiple systems in the body such as the heart, blood vessels, and bones.
Counseling is often an essential part of depression treatment. Many additional integrative treatment options for depression exist, including dietary therapy, lifestyle modification, nutritional supplements, botanical supplements, antidepressant medications, and acupuncture. Seattle is home to a host of naturopathic physicians and other integrative practitioners who utilize these and other natural, alternative, and integrative treatments either as primary therapy for depression or in conjunction with psychological counseling and medication.