Inflammatory Hypothesis

Major depressive disorder is one of the most common mental disorders, with a 12-month prevalence of 6.7% of adults in the United States (NIMH). There is no definite etiology of depression, but several risk factors have been identified. Functional and structural changes in the brain have also been explored. The most common treatment for depression is the use of drugs that act on monoamine transmitters, including norepinephrine, dopamine, and serotonin. Decreases in these transmitters, especially serotonin, were hypothesized to play an important role in the cause of depression (Breedlove & Watson, 2013). The serotonin hypothesis led to the development of selective-serotonin reuptake inhibitors (SSRIs), which increase the amount of serotonin in the brain. Further research suggests that the serotonin hypothesis is not entirely accurate and the neurobiology of depression is much more complex. The “chemical imbalance” explanation of depression may not reflect the full range of causes and may be given greater credibility by patients and doctors than is supported by evidence based research.

Depression is the lack of the chemical compound C10H12N2O or Serotonin. Serotonin is a neurotransmitter, made in the brain to help relay messages from one area or the brain to the other. As a result of serotonin being released throughout one's entire body it is believed to influence a majority of the bodies functions. (WEBMD.) Antidepressants alter the level of serotonin in the person's body, however, if one has excessive serotonin the outcomes could result in mania, agitation, and sometimes even death. Those outcomes are the reason that many doctors suggest going to therapy before prescribing an

Antidepressants have become the most commonly prescribed drugs in the United States. These drugs work in many different ways, but are intended to treat serious psychological disorders such as depression. They can be prescribed by any medical doctor, however, and are often used even when they are not clearly indicated as necessary or even effective. Americans are increasingly turning to antidepressants as a quick fix to real or perceived psychological problems that can often be treated more efficiently in other ways with less risk to their physical well being. Antidepressants are drugs that are primarily used to treat depression, although many are frequently being utilized in other disorders. The main types of antidepressants are tricyclics,

Selective serotonin reuptake inhibitors (SSRIs) have been prescribed by physicians for many years now. One reason SSRIs are so popular is because of the many mental disorders they can be used for such as anxiety, depression, obsessive-compulsive disorder (OCD), phobias, and many more (Weitzel & Jiwanlal, 2001). The four major types of SSRIs that are most commonly used by people with mental disorders are fluoxetine (Prozac), paroxetine (Paxil), sertraline (Zoloft), and citalopram hydrobromide (Celexa); SSRIs work on the brain by acting on the reuptake pathway of serotonin (Stone, 2010). There are some advantages for taking SSRIs. One advantage is that SSRIs have fewer side effects than most of the other antidepressant medications such as monoamine oxidase inhibitors (MAOIs) and tricyclics (Weitzel & Jiwanlal, 2001). Another advantage is that SSRIs have less of a risk of toxicity in overdose (Lane, Baldwin, & Preskorn, 1995). SSRIs are better tolerated than tricyclic antidepressant medication because they cause less sedation and problematic anticholinergic effects. There are also reports indicating that SSRIs have fewer negative effects on the cardiovascular system than tricyclic antidepressants (Edwards, 1992).

Psychiatrists, psychologists, doctors and patients alike were presented with a solution in 1987, the year of Prozac’s introduction. Depression medication held a stigma, and was not expected to become a topic of heated debate and ravenous support. The older Tricyclic drugs such as doxepin and nortriptyline were rarely prescribed for more than nine months and caused disruptive side effects such as dizziness, sluggishness, painful dry mouth and weight gain to name a few (Natalie Angier for NY Times News Service). Prozac became a blessing for many, “fluoxetine was far superior… initially considered almost free of side effects” (SSRI Antidepressant Medications: Adverse Effects and Tolerability). Natalie Angler’s article communicates the well-received

Although this disease in not fully understood, we know several key factors that contribute to this

This depression could be alleviated by drugs that reduces cortisol, which is an evidence of the biological root only. Hence, a biopsychosocial model is not useful for explaining comorbid depression.

The cause of Clinical depression has long been a mystery to physicians and researchers. Many different theories have been proposed, but no conclusive evidence has been put forth. However, most of what we know about depression stems from the results of certain drugs which have been successful in treating the clinically depressed. These anti--depressants have led to the assumption that depression is most likely due to a chemical imbalance (of neurotransmitters) which somehow leads to the symptoms of depression. To try and write a paper on all the theories of depression would be endless, as would be a study on all the different types of

The leading theory explaining the biology of depression is the monoamine hypothesis of depression. (Stahl, 3) This theory suggests that depression is caused by a deficiency in one or another of the three neurotransmitters: serotonin, norepinephrine and dopamine. The theory was formulated after the accidental discovery of the original drugs for depression and psychosis, much in the same way Fleming discovered penicilin.

Most common groups of drugs are known as selective serotonin reuptake inhibitors (SSRI) which increases the level of serotonin (NHS, 2014). Bernstein et al (1994) conducted a study and found out that antidepressant drugs are an effective way to treat depression in the short run, significantly helping 60-80% of people. Cuijpers et al (2011) also supported Bernstein et al (1994) study found out that medication was more effective in psychotherapy in improving symptoms (Cuijpers, et al., 2011). However (Blumenthal, et al., 1999) found that exercising was just as effective as SSRIs in treating depression in an elderly group of patients. In another study conducted by Leuchter and Witte (2002) found that depressive patients receiving drug treatments improved just as well as patients receiving a placebo. The findings suggest that effective placebo treatment induces changes in the brain function that are different from those associated with antidepressants medication, however both treatments are effective, indicating that there are other ways to improve from depression other than antidepressants, which may have side effects (Leuchter, et al., 2002). Generally antidepressants drugs are an effective way to treat depression, but only in the short term. Medication will not cure depression or possible side effects, caused by taking drugs, such as sexual problems, insomnia, and dry mouth (MayoClinic,

Serotonin is a neurotransmitter in the brain that has an immense effect over many functions of the brain. “Cells that make serotonin use tryptophan hydroxylase, a chemical reactor which, when combined with tryptophan, forms 5-hydroxytryptamine”. Serotonin can be discovered three key parts of the body. However, the main location of serotonin lies within the intestinal walls. It is also located within large blood vessels throughout the body and the central nervous system. The most commonly studied area of the body when it comes to serotonin, is how this neurotransmitter effects the central nervous system. The functions of serotonin are abundant and can include the regulation of many important attributes of the human body such as appetite, sleep, mood, behavior, endocrine regulation, and depression.

Serotonin (5-hydroxytryptamine, 5-HT) is a neurotransmitter in the brain that has an enormous influence over many brain functions. It is synthesized, from the amino acid L-tryptophan, in brain neurons and stored in vesicles. Serotonin is found in three main areas of the body: the intestinal wall; large constricted blood vessels; and the central nervous system. The most widely studied effects have been those on the central nervous system. The functions of serotonin are numerous and appear to involve control of appetite, sleep, memory and learning, temperature regulation, mood, behavior (including sexual and hallucinogenic behavior), cardiovascular function, muscle contraction, endocrine regulation, and

(3) While successful drug therapies which act on neurotransmitters in the brain imply that depression is a neurobiological condition (4), the fact that such medications do not help about 20 percent of depression-sufferers seems to show that not all depression is due to such imbalances. Rather, depression is not caused by one single factor; it is most often caused by many different things. Genetics, biochemical factors, medicines and alcohol, developmental and other external factors, and relationships, marriage and children all have effect on the development of clinical depression. (5) The strongest hypotheses on the pathways to depression are in decreases in the activity of specific neurotransmitters, or the overactivity of certain hormonal systems. (3)

These can be caused by a low production of serotonin in our brain or a lack of receptor sites from serotonin to bind to. There are many other ways these problems can become the issue, including the inability for the serotonin to reach these receptor sites or a shortage of the chemical used to make serotonin, Tryptophan. People with depression can take antidepressant drugs, such as SSRI or selective serotonin reuptake inhibitors which help regulate serotonin levels, in order to reduce the symptoms of depression. Serotonin is known as the “happy molecule”, because of its role that it plays in determining your mood. The major serotonin deficiency is depression or the loss of pleasure in normal things you used to enjoy. Other deficiencies in our levels of serotonin include anger, digestive disorders, feeling overwhelmed, insomnia, low self-esteem, and migraines just to name a few. The effects of serotonin are different in men and women in many ways. Women, for instance, are more likely to experience depression, anxiety, and other mood

– Depression, anxiety and bipolar affective disease are common indications for which selective serotonin reuptake inhibitors are prescribed, and these disorders should be anticipated by the attending physician