People can become ____ through different routes, including genetics, traumatic experiences, hormonal problems, substance-abuse, head injuries, brain tumours, and other illnesses.
Despite having different ____, or combinations of causes these people all look and act depressed.
According to the DSM-IV, people with ____ ____ feel sad and helpless every day for weeks at a time. They have little energy, feel worthless, contemplate suicide, have trouble sleeping, cannot concentrate, find little pleasure, and can hardly even imagine being happy again.
Absence of ____ is a more reliable symptom of depression than increased sadness.
Childhood depression is about equally common for boys and girls, but beyond the age of 14, depression is more common in ____.
Although some people suffer from long-term depression, it is more common to have ____ of depression separated by periods of normal mood.
The first depressive episode is special in certain regards. The first episode of generally ____ than most of the latter ones, and most patients can identify a highly ____ event that triggered the first episode.
longer : stressful
For later depressive episodes, people are less and less likely to identify a triggering event. It is as if the brain ____ how to be depressed and gets better at it.
In that regard depression is like ____ and migraine headaches,: the more often you have had an episode, the easier it is to start another.
Studies of twins and adopted children indicate a moderate degree of ____ for depression.
Given the difficulty so far in identifying any gene strongly linked to depression, another hypothesis arose: Perhaps the effect of a gene varies with the ____.
One gene controls the ____ transporter, a protein that regulates the ability of axons to reabsorb serotonin after its release, to recycle for further use.
Investigators examine the serotonin transporter genes of 847 young adults, identifying two types: the ____-type and the ____-type.
short : long
For people with two ____ forms of the gene, increasing numbers of stressful experiences lead to a big increase in the probability of depression. For those with two long forms, stressful events only slightly increased the risk of depression.
However, since then the most researchers have failed to ____ the result, finding no significant relationship between depression and the serotonin transporter gene itself and no interaction between the effects of the gene and stress.
A few cases of depression are linked to ____ ____.
____ maybe another trigger for depression. Stress is accepted as an important factor in depression, and stress increases release of cortisol.
About 20% of women report some degree of ____ ____ – that is depression after giving birth – and many researchers suspect that hormonal fluctuations are a contributing factor.
Among older mean, a declining level of the hormone ____ is associated with increased probability of depression.
Studies of normal people have found a fairly strong relationship between happy mood and increased activity in the left ____ ____.
Most people with depression have decreased activity and the left and ____ activity in the right prefrontal cortex, and this imbalance is stable over the years despite changes in symptoms of depression.
Most people gaze to the right during verbal tasks, but most individuals with depression gaze to the left, suggesting right-hemisphere ____.
____ ____ fall into several categories, including tricyclics, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, and atypical antidepressants.
The ____ (e.g., imipramine, trade name Tofranil) operate by blocking the transporter proteins that reabsorb serotonin, dopamine, and norepinephrine into the presynaptic neurons after their release.
The result of tricyclics is to prolong the presence of the neurotransmitters in the ____ ____, where they continue stimulating the postsynaptic cell. However, they also block histamine receptors, acetylcholine receptors, and certain sodium channels.