Anti-Depressants | Anti-Depressant Medications

Antidepressants all work by controlling the balance of the neurochemistry in the brain. There are three chemicals referred to as neurotransmitters: serotonin, norepinephrine, and dopamine. Each type of antidepressant works to increase the levels of these neurotransmitters and; therefore, has different side effects associated with each type. Since these work differently, some work better than others depending on the individual. Depression is more common that most believe. There are many views regarding the causes of depression and some very interesting genetic studies.

Most psychiatrists will leave all options on the table and consider using even the older line medications because sometimes patients may not respond or have problematic side effects to the newer medications and will respond to the older ones much better. The newer SSRI and SNRI typically begin to work faster with fewer side effects. These medications are very effective although, there is always a small segment of the population that is treatment resistant, in which case, we have other forms of treatment. Most antidepressants take about 4 weeks to show their full effect. When the right medication is found, it is our goal that a patient not have the side effects and that the patient only have a resolution of their depressive symptoms; this is generally the case.

We can't cure the illness with the medication, (though scientists are devoting much research to find the causes and cure for depression through genetic engineering); but we can control it while one is taking the medication. This is why it is important to discuss with one's doctor, problems or reasons why he or she wants to come off of the medication. Too often patients begin to feel normal as the symptoms subside and want to stop the medication abruptly. This often leads to a relapse and in some cases severe side effects from not tapering down the dose of medication. The brain just like any organ can become diseased. The medication corrects the chemical imbalance causing the depressive symptoms, thus resulting in a resolution of the depression. Antidepressants to the brain are like insulin to the pancreas.

Opiates were used up until the late 1950’s and amphetamines through the late 1960’s, but due to the risk of addiction, they fell out of favor. During the early 1950’s, MAOI (monoamine oxidase inhibitors – MAOI is plural) were introduced. The MAOI were first introduced as anti-tuberculosis drugs and are still a mainstay treatment of TB. Once the brain's three neurotransmitters, have played their part in sending messages in the brain, they get disposed of  by a protein in the brain called monoamine oxidase, an enzyme. These MAOI work by blocking this activity. They block the degradation of the monoamine neurotransmitters by inhibiting the enzyme monoamine oxidase, leading to increased concentrations of these neurotransmitters in the brain and an increase in neurotransmission. When the excess neurotransmitters aren't destroyed, they start accumulating in the brain. Since depression is associated with insufficient levels of these monoamines, increasing the monoamines reduce depressive symptoms. MAOI lost their popularity because of their potentially severe side-effects. The major side effect was caused by the increase in tyramine, which can lead to a very serious side effect if these MAOI are  taken with certain foods containing tyramine. Therefore, most of the time, the patient must be on a strict diet, unless they are on the MAOI patch at the lowest dose. Additionally, MAOI have many interactions with other drugs. So, this must be watched closely by the doctor and pharmacist. The patient needs to be aware of this too.

Tricyclic antidepressants (TCA) were discovered shortly after the MAOI, in the late 1950's. Tricyclics block the reuptake of certain neurotransmitters such as norepinephrine and serotonin and to a much lesser extent, dopamine. They are used less commonly now due to the development of more selective and safer drugs. Side effects include increased heart rate, drowsiness, dry mouth, constipation, urinary retention, blurred vision, dizziness, confusion, and sexual dysfunction. Toxicity occurs at approximately ten times normal dosages. These drugs are often lethal in overdoses, as they may cause a fatal heart arrhythmia. However, TCA and some MAOI antidepressants are still used because of their effectiveness, especially in severe cases of major depression and when the SSRI and SNRI classes are ineffective or are giving patients intolerable side effects.
Selective serotonin reuptake inhibitors (SSRI) are a class of antidepressants considered the current standard of drug treatment along with serotonin and norepinephrine reuptake inhibitors (SNRI). Prozac, the first SSRI, was first put on the market in 1988.  A possible cause of depression is an inadequate amount of serotonin, a chemical used in the brain to transmit signals between neurons. SSRI are said to work by preventing the reuptake of serotonin by the presynaptic neuron, thus maintaining higher levels of 5-HT in the synapse and increasing the active levels of serotonin.

Serotonin and norepinephrine reuptake inhibitors (SNRI) is the newest class of antidepressants. SNRI increase levels of both norepinephrine and serotonin. While low levels of both neurotransmitters are associated with depression, norepinephrine is thought to be involved more with alertness and energy, while serotonin influences mood. By increasing levels of both, SNRI work on different aspects of depression.
Typically, my first line of antidepressant medications are the SNRI class of which there are several drugs available. These often begin to take effect in two to four weeks and are effective often 70% of the time. If the patient is not responding well to these, I will move to an SSRI and then if necessary possibly consider augmentation with another medication or move on to the tricyclics. In recent years at my psychiatry practice in Scottsdale, I have also resorted to using an MAOI, which has in fact shown some efficacy. It is important to understand medication management with respect to augmentation as well as using some of the older medications. Some patients that are considered treatment refractory can benefit from augmentation or the use of the older TCA and MAOI. If you want to find a psychiatrist in Scottsdale or metro Phoenix, please contact me through this website or call me to discuss your situation. As a policy, I leave all options on the table with regards to treatment because of the effectiveness and variety of  the medications and therapies that are available today. Someone suffering from depression should seek treatment to have a resolution of their condition.

There are also many benefits from the newer antidepressants in terms of protecting the neurons and thus preventing neuronal cell damage and or death that can result if depression is left untreated. Also, new research is showing us that the sooner psychiatric illnesses are treated from the onset, the more efficacious generally the treatment and the less risk of developing treatment refractory cases in the future.

This article is for informational purposes only and not to be used to diagnose or treat an illness