Symptoms of Major Depression
Feelings of helplessness and hopelessness, sadness, loss of interest in and pleasure from previously enjoyable activities (including food and/ or sex), also known as anhedonia; may be accompanied by significant weight loss or gain, insomnia or hypersomnia (middle of the night awakening, early morning awakening), fatigue, general loss of energy, having hard time concentrating. People with depressive symptoms are often indecisive, have low self-esteem, pessimism; disturbance of body rhythms (sleep-and- wake cycles and appetite), sometimes even suicidal tendencies occur.
Evidence for genetic predisposition for Depression?
Although the impact of genes varies, depending on the type/nature of depression, there is evidence for some correlation. Generally speaking, depression tends to run in families. That is why adopted children, resembling their real parents’ genes may have depression in spite of living in a cheerful, lively atmosphere. A person is at risk of depression if he/she has close relatives who have had severe early-onset depression, especially if that relative is a female. However, no single gene has been identified as having the strongest link with this mood disorder. Most likely, depression depends on a combination of genes, other biological and environmental factors.
Are males or females more vulnerable to depression? What is the role of hormones?
Depression is much more common in women, across all cultures. For sure, hormonal changes can trigger an episode of depression (specifically, but not only, in cases of postpartum depression). Still, the reason why women suffer depression more often is not clearly identified.
What is the role of traumatic experiences for episodes of depression?
Stress is a typical trigger for an episode of depression, as it causes the release of the stress hormone cortisol that prepares the body for action and, in the long run, exhausts the body and the nervous system. A lot of women experience postpartum depression, after giving birth and some of them enter a more serious, long lasting depressed condition. However, giving birth itself does not cause depression as many of the women have already suffered previous onsets. Thus, traumatic experiences may trigger an episode of major depression, but do not necessarily cause the disorder.
What are the 3 major groups of antidepressants? How does each of them exert its effects?
Tricyclics prevent the brain cells (neurons) from reabsorbing the neurotransmitters catecholamines or serotonin (both of which are related to improved mood and energy) after they have been released. Thus, these neurotransmitters remain available in the brain much longer, continuing to stimulate the the brain cells, contributing to improved mood. These medications also reduce the reuptake of Norepinephrine (noradrenaline) and Dopamine (also strongly related to elevated mood and energy levels). Unfortunately, tricyclic also block certain receptors which may lead to some of their side effect.
Selective serotonin reuptake inhibitor (SSRIs) block the breakdown of serotonin (the feel good hormone) by the brain cells. SSRIs have little and only mild side effects. Still, sometimes, they may cause nervousness and, thus, are *not recommended for people suffering anxiety.
Monoamine oxidase inhibitors (MAOIs) block the enzyme monoamine oxidase, which has the function to metabolize catacholamines (adrenaline, noradrenaline and dopamine, all of which are related to elevated mood and normal energy and stress response) and serotonin (the feel good hormone) into an inactive form. When this enzyme is blocked, the amount of these neurotransmitters in the brain increases. However, MAOIs tend to affect blood pressure, which could potentially be dangerous in the long run, although these medications tend to work within a few days.
Why is Prozac/ fluoxetine often preferred over tricyclics and the monoamine oxidase inhibitors?
It has almost no side effects (sometimes mild nausea, headache, or nervousness). Also, there is almost no risk of overdose. In addition, it takes only within 2 – 4 weeks to work and, in the short run, causes loss of weight, which is desired by many people.
How effective is St. John’s wort? Which class of antidepressants produces similar effect? What is one potential problem?
St. John’s wort is an herb that works in a way similar to that of selective serotonin reuptake inhibitors. However, its efficacy has not been accurately determined yet. Different studies show different results (some suggest it is more effective that SSRIs, some claim it is equal to them, others, that it is not effective at all). One potential dangerous side effect is that St. John’s wort is the increased production of the liver enzyme that breaks down toxins and also medication. Thus, it decreases the effectiveness of many medicines that may be vital. Another potential problem is that it is cheaper that drugs and can be taken without prescription, which hides the risk of inappropriate use and dosage.
How does the onset of REM (deep sleep) sleep differ in depressed people, compared in non-depressed? How may this be related to body temperature cycles?
People with mood disorders also suffer some disturbance of their biological rhythms. Depressed people have trouble sleeping and people who have sleep problems are more likely to get depressed, pointing to an interesting and important relationship between the two. After going to sleep, most non-depressed people enter REM sleep after about 80-90 minutes and the amount of REM sleep is increased in the second half of the night. Depressed people, however, enter REM phase of sleep after about 45 minutes after going to bed. Also depressed individuals have trouble staying asleep and often feel drowsy the next day.