Answer to Question 1
Low levels of depression in relation to norepinephrine and dopamine are thought to be related to the etiology of depression. The permissive hypothesis argues that when serotonin levels are low, other neurotransmitters are permitted to range more widely and so become deregulated. EEG studies suggest that depressed individuals exhibit greater right-side anterior activation in their brains and lower levels of such activity on the left side than nondepressed individuals. Negative thoughts or attributions about themselves, the immediate world, and the future are characteristic of depressed individuals.
Antidepressant medications can effectively treat depression but may take several weeks to work, and symptoms may reappear when the medication is continued. Cognitive-based treatments take longer to work but can be instrumental in limiting later depression. The combination of both is often the most effective treatment.
Answer to Question 2
Major depression is characterized by a depressed mood state that lasts at least two weeks and includes cognitive symptoms such as feeling worthless, disturbed physical function such as altered sleep or appetite, and the loss of interest and pleasure in activities and social interactions.
Persistent depressive disorder shares the symptoms of major depressive disorder, but the symptoms are milder, although they last over longer periods of time.
Double depression occurs when a person has persistent depressive disorder (dysthymia) and experiences a major depressive episode
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