Symptoms, Causes Of Depression And BBT

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Daily events and the way that we react to them can sometimes trouble our peace of mind. Anyone can go through a period when they feel sad and lonely every day. But when feelings like this go on for weeks or even months, they may be the first signs of depression.

An estimated 1 out of 5 women and 1 out of 10 men will experience depression at some time in their lives, which makes this a very common ailment. Depression can prevent people from coping with their normal activities, their work, and their relationships, thus seriously compromising their sense of well-being and their ability to live their lives. 

Psychiatrists generally consider someone to be suffering from depression when they present at least 5 of the following symptoms almost every day for at least 2 weeks:

Once a doctor diagnoses depression, it is important to begin a course of treatment as quickly as possible, to prevent the depressive state from getting worse. Left untreated, depression tends to become chronic or recurrent, and major depression leads to suicide in about 15% of the people who suffer from it.

Research on the causes of depression has increasingly revealed how complex this disease is and how many different factors can contribute to its onset.

SYMPTOMS, TREATMENTS, AND CAUSES OF MANIC DEPRESSION

Manic depression has been known since ancient times, but it was a German psychiatrist, Emil Kraepelin, who first described its symptoms more systematically, in the late 1800s. Today, specialists prefer the expression “bipolar disorder”, which avoids the negative connotations associated with the word “manic”.

Both the painter Vincent Van Gogh and the author Ernest Hemingway suffered from manic depression throughout their lives.

Unlike ordinary people whose moods are influenced by specific events in their lives, people with bipolar disorder seem to follow their own cycle of mood fluctuations. Like passengers strapped into a roller coaster, they have no choice about the ups and downs; they must simply go along for the ride.

And “ups and downs” is an appropriate description, because unlike depression (also known as “unipolar disorder”), bipolar disorder includes not onlydepressive states characterized by the same systems as depression, but also “manic” episodes that alternate with them.

During these manic phases, individuals are excessively exuberant. Their thoughts race feverishly, leading to extravagant behaviour. They see patterns everywhere—everything seems connected to everything else, and the smallest event can take on an exaggerated meaning. These people can also be very creative; the connections that they draw between things constantly inspire them with new ideas and new theories.

More systematically, specialists often distinguish four major categories of <a href='http://drkevinconners.com/the-clinic/anxietydepression">depression symptoms</a>of manic episodes:

1) External appearance. The individual’s external appearance is extravagant or sloppy, provocative, or even indecent. A person in a manic phase may call out to strangers in the street with an abrupt familiarity, sometimes mixed with sarcasm.

2) Mood exaltation. During manic phases, individuals feel exuberant and have extreme confidence in their own powers and charm. They have sexual adventures with no thought for the possible consequences and often with a total lack of inhibition or tact. They do not tolerate any criticism of themselves and are easily irritated and angered.

3) Accelerated thought processes. Manic individuals’ thoughts come so fast that their words can’t keep up with them. They evoke one image, then move on to the next before their listeners have had time to absorb the first one. They keep jumping from one unrelated topic to another and keep talking even if people have stopped listening. Their ability to focus their attention is greatly diminished, but their imagination is greatly amplified.

4) Motor hyperactivity. In manic phases, people don’t know the limits of their own strength. They don’t take the time to eat or sleep. They take on several projects at once without stopping to determine whether they are even feasible. These individuals make major upheavals in their lives (change jobs, go on long trips, make foolish expenditures, etc.) and may become distrustful or even paranoid, accusing the people around them of wanting want to keep them from carrying out their grandiose plans.

From all these symptoms, one can easily see why it is vital to ensure that people with bipolar disorder receive appropriate treatment quickly. Even though the causes of these diseases are still incompletely understood, there are ways to reduce their effects considerably.

In general, several regions of the brain are less active in people who are depressed than in people who are feeling in top form. The reduced activity in these areas probably explains why depressed people experience feelings of lethargy and exhaustion.

But major depression does not represent a malfunction in a single part of the brain. It is more likely due to a variety of brain abnormalities.

Scientists believe that the prefrontal cortex may act as a kind of brake that keeps emotional responses in check. When this brake becomes less effective, it might therefore give freer rein to negative emotions arising from the limbic structures, which are generally hyperactive in patients with depression or bipolar disorder. Antidepressant medications tend to reverse this pattern, increasing activity in the cortex while reducing hyperactivity in the limbic system.

Brain imaging studies have shown that patients suffering from depression have the same patterns of brain activity as schizophrenics who have negative symptoms (that is, who are introverted and apathetic rather than eccentric and agitated). The parts of the brain that are less active in both diseases (such as the frontal lobes) are the ones recognized as making people feel that they are in control of their own actions. 

Similarly, both paranoid schizophrenics and people in the manic phase of bipolar disorder display hyperactivity in the prefrontal cortex. In the former group, this hyperactivity is expressed as a tendency to draw connections between things and events but to give these connections a hostile connotation. In the latter group, the connections have more of a euphoric effect.

Surprisingly, the experts still don't know why elevating serotonin levels with antidepressants makes people calmer and more likely to make long-term efforts to improve their mental health, such as entering psychotherapy. Nor do the experts know why antidepressants generally take three to six weeks to start improving a patient's mood, or why these drugs can improve the mental condition of people who are not clinically depressed, but simply shy or compulsive.

In the late 1990s, however, some scientists offered an hypothesis that might help to solve a fair share of these mysteries: that the mechanism by which antidepressants that increase serotonin levels improve depressive states is byencouraging the growth of new neurons in a particular region of the brain.

New neuron that has grown in the hippocampus of an adult mouse
Source: Henriette van Praag, Salk Institute for Biological Studies, USA

What makes this hypothesis so interesting is that the region in question is the hippocampus, which is already known to lose large amounts of neurons in people who experience prolonged stress or prolonged states of depression.

Depression does not appear to be due solely to an imbalance between certain chemical messengers in the brain. Recurrent depressions may be more like a degenerative disease in which some nerve cells and neural connections are damaged or destroyed. Ultimately, it is the individual's abilities to adapt to new situations that become impaired.

Taken in large doses, antidepressants may also affect the structure of neurons in other ways that we would tend to equate with brain damage. Thus these substances not only re-establish the equilibrium of certain neurotransmitters but also probably produce changes in the structure of numerous neural networks.

SEROTONIN AND OTHER MOLECULES INVOLVED IN DEPRESSION

Serotonin is a chemical messenger in the central nervous system and is involved in many physiological functions, including sleep, aggression, eating, sexual behaviour, and depression.

Serotonin is produced by a particular type of neurons, named accordingly: theserotonergic neurons. The cell bodies of these neurons are grouped in several nuclei in the brainstem. A decline in the activity of these neurons is believed to be associated with various forms of depression, in particular those that lead tosuicide.

Serotonin is a molecule composed of 10 carbon atoms (black), 12 hydrogen atoms (white), 2 nitrogen atoms (blue), and 1 oxygen atom (red).

But scientists have been able to measure the decline in serotonin levels in the bloodstreams of depressed people only indirectly. After serotonin is released from the nerve ending of a neuron, it is either reabsorbed by that neuron or broken down into another molecule, known as a serotonin degradation by-product. Thus, the more serotonin there is in someone's brain, the more serotonin degradation by-product there will be in that person's blood. In the blood of depressed people, the levels of this by-product have often been found to be abnormally low, which suggests that their serotonin levels are abnormally low as well.

There are specific receptors for serotonin on neurons in several different parts of the brain. Depending on the type of serotonin receptor, serotonin will either excite or inhibit the activity of the neuron on which this receptor is located. Thus it is the differences in the types of serotonin receptors that explain why the same molecule can have a variety of effects.

ANTIDEPRESSANTS

Depression has been linked to imbalances in certain chemical messengers in the body, such as serotonin, norepinephrine, and dopamine. Antidepressants—medications that effectively relieve the <a href="http://drkevinconners.com/the-clinic/anxietydepression">symptoms of depression</a> —  act directly on these neurotransmitters, which represents strong evidence that these chemical messengers are involved in this disorder.

Starting in the mid-20th century, as scientists began to suspect that there were somebiochemical bases for depression, they developed several hypotheses that attributed a key role to neurotransmitters: chemical messengers such asserotonin, norepinephrine, and dopamine. The discovery of antidepressant medications-molecules that could effectively calm the symptoms of depression-lent support to these hypotheses, because these molecules acted specifically on these neurotransmitters.

It should be remembered, however, that the primary purpose of neurotransmitters is to let neurons communicate with one another. Thus these diseases must be regarded as the result of disturbances in the communications between neurons.Such disturbances can occur at any of the steps in the transmission of neurotransmitters across synapses and are also the source of the effects that drugs have on the brain. Some of the street drugs that people take to get high—such as ecstasy—exert their effects through mechanisms similar to those of antidepressants.