Excessive Television Exposure in Teens Linked to Depression in Adulthood

February 5, 2009 — Excess exposure to television in teens has been linked to an increased risk for depression in early adulthood, particularly among young men.

A large longitudinal study from investigators at the University of Pittsburgh, in Pennsylvania, shows that each extra daily hour of television use was associated with an 8% increase in the odds of developing depressive symptoms by young adulthood.

"We looked at the development of depression over a 7-year period and found that the amount of television exposure was significantly associated with the development of depression," principal investigator Brian A. Primack, MD, told Medscape Psychiatry.

The study is published in the February issue of Archives of General Psychiatry.

Leading Cause of Morbidity Worldwide

Although previous studies have investigated the relationship between electronic media and mental health, this research has largely been cross-sectional and has primarily focused on anxiety.

Findings from these studies have shown a link between excessive use of certain media, social anxiety, and a decline in interpersonal relationships.

Researchers wanted to explore the relationship between media exposure and depression, which has been cited by the World Health Organization as the leading cause of morbidity worldwide and is very common in adolescence.

They hypothesized that an excessive amount of television watching during adolescence would increase depression in young adulthood and would have a greater impact on young females than their male counterparts.

They also theorized that television exposure would turn out to be more potent than other types of electronic media, including videocassettes, computer games, or radio. (The data for the study were collected before Internet use was widespread and prior to the introduction of DVDs).

Males at Greater Risk

Using data from the National Longitudinal Survey of Adolescent Health, investigators looked at the relationship between electronic media exposure in 4142 adolescents who were not depressed at baseline and the subsequent development of depression at 7-year follow-up from 1995 to 2002.

At baseline, teens were asked about the number of hours they had spent during the previous week watching television or videocassettes, playing computer games, or listening to the radio.

Subjects reported an average of 5.68 hours of media exposure per day, including 2.3 hours of television, 0.62 hours of videocassettes, 0.41 hours of computer games, and 2.34 hours of radio.

At follow-up, 308 (7.4%) participants reported symptoms consistent with depression, and researchers found these individuals had watched more television than nondepressed individuals at baseline — 2.64 hours vs 2.28 hours per day — and that this association was statistically significant. However, there was no association between these symptoms and exposure to other media types.

Surprisingly, in contrast to their original hypothesis, the researchers found that, compared with young men, young women were less likely to develop depression given the same total media exposure.

"At study outset, we felt females were more likely to be affected because of all the images that are pervasive in the media of the 'feminine ideal' of thin, beautiful women. However, the study showed the opposite was true," said Dr. Primack.

Greater "Social Reserve" in Girls?

One possible explanation for this finding, he said, is that the impact of media content that presents idealized masculinity and sex roles on the psychological development of young males has been underappreciated.

"The bottom line is that males are also held to a high standard in the media, and it is possible that, for a number of reasons, those portrayals might be more powerful that we had previously thought," he said.

Another possible explanation is that young females have more "social reserve" than young males, which increases their resilience.

"We know that during adolescence and even in early adulthood females have closer relationships than young males. So if a boy watches several hours of television a day, this may substantially displace social interaction. Girls, however, may be able to watch the same amount of television while still maintaining their social relationships," said Dr. Primack.

More research is needed to better understand the mechanisms at play and whether it is the amount of media exposure, the type of media content adolescents are exposed to, or some other mechanism that underlies this association.

Need for Media Literacy

In the meantime, said Dr. Primack, the study has implications for clinicians, including psychiatrists, pediatricians, family physicians, internists, and other health providers who work with adolescents, to ask about television and other media exposure. It also has implications for researchers and research funding agencies.

"At this point, we have enough substantial data from studies like this linking large amounts of media exposure to major health concerns such as substance use, obesity, and aggression. So moderating the amount of media an individual consumes is certainly something physicians can and probably should suggest," he said.

Teaching media literacy, the critical analysis of media content, is also something that should be considered on a widespread basis, he added. "Individuals who are media literate should be better equipped to navigate the modern world. They may be less susceptible to the messages from the barrage of media that are all around us these days. They may even be more psychologically fulfilled because they will set their own goals instead of allowing advertisers and marketers to set their life goals for them," said Dr. Primack.

Arch Gen Psychiatry. 2009;66:181-188. Abstract

Written by Caroline Cassels from Medline

What Is Serotonin?

Serotonin is a hormone that is found naturally in the human brain; it is also found in the digestive tract and platelets of some animals, including human beings. It is also found in a variety of plant sources, including vegetables, fruits, and even mushrooms. Categorized as a neurotransmitter, it is important in transmitting nerve impulses. It is also described as a vasoconstrictor, which is a substance that can cause narrowing of the blood vessels. The amino acid tryptophan is credited with producing serotonin in the body.

Serotonin can be considered a "happy" hormone, as it greatly influences an overall sense of well-being. It also helps to regulate moods, temper anxiety, and relieve depression. It is also credited with being a natural sleep aid. It even plays an important role in regulating such things as aggression, appetite, and sexuality. It also helps with regulating body temperature and metabolism and plays a role in the stimulation of vomiting.

Since serotonin is so important in regulating moods and feelings of well-being, it is often targeted in drugs that are used to affect the mood, such as antidepressants. A class of medications called monoamine oxidase inhibitors (MAOIs), such as Marplan and Nardil, works to prevent the breaking down of neurotransmitters, allowing them to increase in the brain and relieve depression. Unfortunately, these drugs have many serious side effects, and they tend to react dangerously with some other types of medication.

Selective serotonin re-uptake inhibitors (SSRIs), such as Celexa, Zoloft, Lexapro, and Prozac, are also used to fight depression, yet they have fewer side effects, and they tend to react better than other medications. Not all antidepressants work to increase serotonin in the brain, however. Some, like tricyclic antidepressants, such as Elavil, actually work against neurotransmitter reuptake.

A link between food and serotonin?

Just what is the link between food and serotonin, and can a change in your diet make a difference?

Serotonin is a neurotransmitter, which has gotten a lot of attention in the last few years. The reason is that low serotonin levels have been linked to depression, lack of concentration, obesity, sleeplessness, and, of course, migraine.

But the food and serotonin link is more complicated than just eating foods containing serotonin. Your body doesn't get serotonin from foods, but makes serotonin from tryptophan. Tryptophan is an amino acid which is essential for the body to get. It is the precursor to more than one neurotransmitter.

You may be able to increase levels of tryptophan by eating foods like breads, pastas, candy ... but wait! That's no good. It may temporarily help if you're depressed (or it may not!), but it's not going to really help anything in the long run.

Is there another way?

Yes, there are a couple other ways. You can find the food and serotonin link in items that are somewhat healthier. Try turkey, black eyed-peas, black and English walnuts, almonds, sesame or pumpkin seeds, and cheddar, gruyere or swiss cheese. Also helping to a lesser extent are whole grains, rice, and other dairy products (grandma was right – drink a glass of warm milk before bed!).

Examples of food with tryptophan:
wheat germ - 0.4g/1cup
granola - 0.2g/1cup
cottage cheese - 0.4g/1cup
egg - 0.1g/1
duck - 0.4g/quarter lb
turkey - 0.37g/quarter cup
chicken - 0.28g/quarter cup

* list from The Healing Nutrients Within by Dr Eric R Braverman.

Gene Variants in Adolescent Anxiety and Major Depressive Disorder

Anxious and Depressed Teens and Adults: Same Version of Mood Gene, Different Brain Reactions

An NIMH study using brain imaging shows that some anxious and depressed adolescents react differently from adult patients when looking at frightful faces. This difference occurs even though the adolescent and adult patients have the same version of a mood gene. Researchers in the NIMH Mood and Anxiety Disorders Program and colleagues reported these findings online October 31, 2008, in the journal Biological Psychiatry.

Background

Anxiety and depression are influenced by the processing of the mood-regulating brain chemical called serotonin. A protein known as the serotonin transporter directs serotonin from the space between nerve cells back into the cells, where it can be reused. Changes in the gene that codes for the serotonin transporter can lead to decreased transport of serotonin back into the brain’s nerve cells. Abnormalities in the serotonin system are associated with anxiety and depression.

Everyone inherits two copies of the serotonin transporter gene—one from each parent. The gene has various versions—one version is short, and one version is long. A person may have two copies of the same version or one copy each of two different versions. Previous studies in adults have linked versions of the gene to increased risk for mood and anxiety disorders. Adults who have one copy of the short version tend to be more anxious and depressed than adults who have two copies of the long version.

Previous brain imaging studies in adults linked gene versions to different responses of the brain’s fear hub—the amygdala—to frightful faces. In both healthy and affected adults who have at least one copy of the short version, the amygdala reacts more than it does in healthy or affected adults who have two copies of the long version of the gene. Whether these findings in adults also hold true for adolescents was unknown.

Using functional magnetic resonance imaging (fMRI), Jennifer Y. F. Lau, Ph.D., then at NIMH and now at the University of Oxford, U.K., and colleagues at NIH scanned the brains of 33 healthy teens and 31 teens with depression and anxiety disorders while they viewed pictures of frightful faces. Then the investigators compared the amygdala reactions in the two groups.

Findings of This Study

Lau and colleagues found that in healthy adolescents who have at least one copy of the short version of the gene, the amygdala reacts more than it does in healthy adolescents who have two copies of the long version. This result is the same in healthy adults. However, in anxious or depressed adolescents, the opposite results were found. In affected adolescents who have at least one copy of the short version, the amygdala reacts less than it does in affected adolescents who have two copies of the long version.

Significance

This finding in affected teens with two long version genes is the opposite of that observed in anxious or depressed adults. It is surprising because anxiety and depression during adolescence tend to predict these disorders during adulthood.

What’s Next?

The unexpected finding may be explained by the fact that anxious adults and anxious adolescents react differently when presented with threats. But further research is needed to fully understand the difference, the investigators say.
Reference

Lau JY, Goldman D, Buzas B, Fromm SJ, Guyer AE, Hodgkinson C, Monk CS, Nelson EE, Shen PH, Pine DS, Ernst M. Amygdala Function and 5-HTT Gene Variants in Adolescent Anxiety and Major Depressive Disorder. Biological Psychiatry. 2008 Oct 23. Source: Medline