Mood and Neurotransmitters

The Mood Hormones Although brain chemical imbalances that cause depression are complex, researchers believe that a few main hormones are responsible for promoting feelings of wellbeing. These hormones are norepinephrine, dopamine and serotonin. Another name for these hormones is monoamine transporters; that is they carry important messages along the neural pathway in the brain. Where an imbalance of these hormones occurs, a mood, energy or cognitive problem results. This is why these hormones are closely associated with depression. Norepinephrine is produced by the adrenal glands and nerve cells to help us maintain energy and activity. Norepinephrine is also called noradrenalin and behaves similar to adrenalin, in that it is released in reaction to anger or emergency. As with serotonin related antidepressants, norepinephrine related medications do not increase levels of norepinephrine, but attempt to help the sympathetic nervous system to process it more efficiently. Dopamine is associated with euphoria and our desire or motivation. Dopamine is also connected with the information pathway in the brain. A dopamine disorder or imbalance can cause memory and cognitive loss as well as difficulty with problem solving. Serotonin may help us feel energetic, calm and assured. Most mood problems are associated with serotonin imbalances. Because the vast majority of depression sufferers may have low levels of serotonin, and because most medications seek to increase serotonin levels, serotonin is discussed here in more detail. Low levels of serotonin not only affect mood, but the ability to cope with strong emotions. Low serotonin may also inhibit sensitivity to possible consequences, which may explain why aggression, impulsive behavior and suicide are prolific in people with low serotonin levels. How Low Serotonin Causes Depression Serotonin may affect depression in two ways. First, someone may suffer from a genetic disorder that causes serotonin to be processed inefficiently in the brain. Researchers have found that the 5HTT serotonin receptors can be too short, causing serotonin to be absorbed too quickly. This depletes the available supply of serotonin, causing mood and energy problems. Most antidepressant medications are designed to slow down this process and so are called ‘selective serotonin reuptake inhibitors’ (SSRI’s). The second way that serotonin may be depleted is through the brain’s defensive reaction to strong emotional stimuli, such as stress or trauma. Limiting the amount of serotonin causes one to be insensitive to impending danger or consequences. Repeated thoughts about or exposure to these conditions reinforces the brain’s reduced serotonin production. While this may help insulate one from a harmful consequence, it also causes mood problems, aggression and impulsive or risky behavior because the sufferer is no longer sensitive to possible consequences. Suicide is the most extreme, self-directed form of this type of aggression. Raising Serotonin Several drugs have been successful at increasing serotonin levels. Tricyclic antidepressants were first discovered almost 50 years ago and are effective at blocking serotonin from being absorbed. However, tricyclics caused many side effects and in some cases increased the risk of suicides. Tricyclics are so named for their distinctive three-ring molecular composition. Doctors now generally favor SSRI’s over tricyclics because of fewer side effects. SSRI’s are the most common antidepressant medications, and some variations work on both serotonin as well as norepinephrine. Monoamine oxidase inhibitors ( MAOIs ) prolong the effect of monoamines such as serotonin, by retarding the breakdown of these hormones. However, MAOI’s increase the risk of several side effects and react negatively with other medications and some foods. MAOI’s are generally prescribed only for specific conditions such as agraphobia or when SSRI’s are ineffective. Medications Alone Aren’t the Answer Although newer forms of anti depressants promise fewer side effects, one single approach is rarely effective, leaving doctors and patients searching for additional methods or a combination to safely restore serotonergic balance. Additionally, antidepressants can cause serious withdrawal symptoms such as rebound depression and insomnia that are worse than the original malady. Are Antidepressants Ineffective? FDA Advisory Letter on Depression In March of 2004, after an exhaustive review of depression studies, the FDA released a position letter on the effectiveness of current antidepressants. Some of the previously private studies revealed a higher placebo vs medication response, and critical editorials of this information claimed that antidepressants aren’t nearly as effective as once believed. As a result, the FDA lists the need for closer physician monitoring, especially in the case of children and those professing suicide ideology. For more information on the FDA’s advisory, click here. Breakthrough in Depression Research One of the most promising discoveries in depression research is the discovery of specialized bright light’s role as an active antidepressant. In 1984, researchers at the National Institute of Health (NIH) successfully used light to treat Seasonal Affective Disorder (SAD). Since then, specialized light has been used to treat sleep disorders and other mood disorders including depression. Specialized bright light causes an antidepressant response in three ways: 1. Bright light activates the production of brain serotonin. In 2002, the Lancet reported that exposure to bright light immediately increased brain serontonin, while dark and cloudy days depleted serotonin levels. 2. Bright light regulates the Suprachaismatic Nucleus, or body clock. With the discovery of specialized light in 1984, researchers discovered that the body clock, located in the hypothalamus, was responsible for sleep/wake and energy/mood cycles. In addition to becoming imbalanced from the lack of light (As with Seasonal Affective Disorder, researchers have also learned that the body clock can easily become inbalanced from stress, trauma, surgery, age, etc. Many people who suffer from depression also have a body clock problem, as they suffer from sleep problems and feel worse at a particular time of day. 3. Bright light suppresses the hormone melatonin. Melatonin is released in the evening time as a signal for the body to withdraw and prepare for sleep. Melatonin is converted from serotonin, and so lowers available serotonin. It also causes feelings of irritablity, withdrawl and sadness. Melatonin is important as a nighttime hormone but daytime or too much melatonin can cause mood problems. Several studies have documented the advantage of specialized light for depression. Patients responed to light within a week verses several weeks for medication, and light posed no long-term negative side effects. A review of light therapy in Archves of General Psychiatry concluded the following: “The evidence is in that light is an active neurobiological agent. But light therapy has little chance to be widely and properly used for a variety of ills, as long as it appears to the policymakers and grantgivers to lie uncomfortably between pharmaceutical company neglect (for obvious reasons) and the molecular reductionism of academe. These attitudes strikingly contrast with patients' acceptance of light therapy. Light therapy is easy to administer in outpatient settings, lacks major side effects, and, importantly, is cost-effective. Whatever its mode of action, it demands inclusion in the antidepressant armamentarium, now.” —Archives of General Psychiatry, October 1998 More Effective Than Medication Although light has been found to be effective by itself, studies show that a combination of light and medication is more effective than either method alone. Patients responded much quicker with a higher quality of response. Sleep problems improved as well. In addition to standard light therapy, a novel new treatment, called wake therapy offers relief within 24 hours. Wake therapy involves partial sleep deprivation and morning light therapy to sustain the anti depressant effects of wake therapy. As with standard light therapy treatment, a combination of wake therapy, bright light and medication is most effective. Offical Recommendation Specialized bright light is recommended by the American Psychiatric Association (APA) as well as the American Acadamy of Sleep Medicine. In January 2004, the Cochrane Medical Library issued the Cochrane Review of all depression related light therapy studies, and recommends light therapy for depression treatment. (Cochrane is considered by the medical industry to be the gold standard in medical review.)