The use of the word âprobablyâ in the sentence below indicates that the evidence is fairly strong. In the second sentence, the more tentative word âcouldâ was selected, indicating that the evidence is weak. The fire was probably caused by a fault in the engine temperature gauge.
There are several types of depression medications (antidepressants) used to treat depression and conditions that have depression as a component of the disease, such as bipolar disorder. These drugs improve symptoms of depression by increasing the availability of certain brain chemicals called neurotransmitters. It is believed that these brain chemicals can help regulate brain circuits that affect emotions. Major types of antidepressants include: 1  Tricyclic antidepressants (TCAs) are some of the first antidepressants used to treat depression.
Antidepressant drugs do their work by either increasing the production of neurotransmitters or by breaking them down. There are three major neurotransmitters that are involved in depression. These are called dopamine, norepinephrine, and serotonin. Serotonin is sometimes called 5-HT. When the levels of one or more of these neurotransmitters dip or become unbalanced, depression or other conditions may result. The newest class of antidepressants is called selective serotonin and norepinephrine reuptake inhibitors (SNRI's). The drugs from this class used for depression are Effexor XR (venlafaxine), Cymbalta (duloxetine), and Pristiq (desvenlafaxine). SNRI's are capable of acting on both norepinephrine and serotonin.