Zoloft, or sertraline hydrochloride, is an anti-depressant drug that belongs to the class of selective serotonin reuptake inhibitors. This class of drug is among the most common prescribed for major depression. In some cases, Zoloft is combined with drugs that increase the brain's levels of norepinephrine, such as bupropion. There is a direct link between elevated norepinephrine levels in the brain and increased dopamine levels. A newer class of drugs, which includes venlafaxine, reboxetine and mirtazapine, works directly on both serotonin and norepinephrine. Both Zoloft and drugs that increase norepinephrine levels can cause anxiety.
Selective Serotonine Reuptake Inhibitors
Selective serotonin reuptake inhibitors, or SSRIs, block the serotonin transporter in the brain. This transporter carries serotonin from extracellular regions in the brain and back into the cells. This prevents serotonin from binding to and activating neurons elsewhere in the brain. By blocking this transporter, SSRIs increase the amounts of serotonin available for activating other neurons. The elevated blood levels of serotonin has a calming effect on activity in the amygdala, the brain's fear processing center. This normally alleviates conscious or subconscious fear associated with depression and anxiety.
Dopamine-raising Anti-depressants
As low dopamine levels can cause a lack of interest and motivation, raising the brain's levels of dopamine can sometimes help alleviate symptoms of depression. Bupropion is a norepinephrine reuptake inhibitors. It elevates norepinephrine levels in the brain by blocking the norepinephrine transporter. Third-generation antidepressants, such as venlafaxine, block both the serotonin and norepinephrine transporters. Drugs that blog the norepinephrine transporter increase dopamine levels in the brain, because this transporter is partially responsible for recycling dopamine.
Zoloft and Anxiety
Zoloft normally reduces anxiety after the recommended induction period of six weeks. The producers of Zoloft, however, list tremor and agitation among the potential side effects of the drug. Tremor and agitation are common signs of anxiety. So, despite its potential positive effect on anxiety, it is possible that Zoloft can increase anxiety in some individuals.
Dopamine and Anxiety
While dopamine can help alleviate depression and anxiety that are associated with a lack of motivation, it does not reduce the energy-state of the body. Dopamine is also sometimes known as the motivational neurotransmitter. It is the neurotransmitter that motivates us and puts us in a position to control important muscle groups. Individuals with Parkinson's disease lack control of movement due to low dopamine levels. While increasing dopamine levels can help with motivational issues and a lack of self-esteem, it can also increase the energy levels of the body to an extent that gives rise to anxiety, irritability and aggression.
References
- Zoloft.com: Zoloft Sertraline HCL Official Site
- "CNS Drugs"; Third-Generation Antidepressants: Do They Offer Advantages Over the SSRIs?; Olver J.S.; Burrows G.D.; Norman T.R.; December 2001
- MayoClinic.com: Parkinson's Disease
- MayoClinic.com: Selective Serotonin Reuptake Inhibitors
- Wellbutrin: Official Site
