Personality and Mood Disorders Q 3
Nurse Rica is teaching a client and her family about the causes of depression. Which of the following causative factors should the nurse emphasize as the most significant?
A. Brain structure abnormalities
B. Chemical imbalance
C. Social environment
D. Recessive gene transmission
Correct Answer: B. Chemical imbalance
Chemical imbalance of neurotransmitters in the brain is the most significant factor in depression. However, the exact cause has not been established, so other factors may also be involved. The underlying pathophysiology of major depressive disorder has not been clearly defined. Current evidence points to a complex interaction between neurotransmitter availability and receptor regulation and sensitivity underlying the affective symptoms.
Option A: Vascular lesions may contribute to depression by disrupting the neural networks involved in emotion regulation—in particular, frontostriatal pathways that link the dorsolateral prefrontal cortex, orbitofrontal cortex, anterior cingulate, and dorsal cingulate. Other components of limbic circuitry, in particular, the hippocampus and amygdala, have been implicated in depression.
Option C: A person’s social environment, including lack of support systems, may also increase the risk of depression. The etiology of major depressive disorder is multifactorial with both genetic and environmental factors playing a role. First-degree relatives of depressed individuals are about 3 times as likely to develop depression as the general population; however, depression can occur in people without family histories of depression.
Option D: Although genetic transmission certainly may be a factor, no definite pattern of transmission has been identified. Some evidence suggests that genetic factors play a lesser role in late-onset depression than in early-onset depression. There are potential biological risk factors that have been identified for depression in the elderly.