Depression is a very common affective disorder involving feelings of sadness that are much more severe and longer lasting than the suspected precipitating event, and the mood of affected individuals is much more intense. The depression may not even be traceable to a specific event or stressor (i.e., there are no external causes). Patients who are depressed may have little energy, sleep disturbances, a lack of appetite, limited libido, and inability to perform activities of daily living. They may describe overwhelming feelings of sadness, despair, hopelessness, and disorganization.
In many cases, the depression is never diagnosed, and the patient is treated for physical manifestations of the underlying disease, such as fatigue, malaise, obesity, anorexia, or alcoholism and drug dependence. Clinical depression is a disorder that can interfere with a person’s family life, job, and social interactions. Left untreated, it can produce multiple physical problems that can lead to further depression or, in extreme cases, even suicide.
Research on the development of the drugs known to be effective in relieving depression led to formulation of the current hypothesis regarding the cause of depression. Scientists have theorized that depression results from a deficiency of biogenic amines in key areas of the brain; these biogenic amines include norepinephrine (NE), dopamine, and serotonin (5HT). Both NE and 5HT are released throughout the brain by neurons that react with multiple receptors to regulate arousal, alertness, attention, moods, appetite, and sensory processing.
Deficiencies of these neurotransmitters may develop for three known reasons. First, monoamine oxidase (MAO) may break them down to be recycled or restored in the neurons. Second, rapid fire of the neurons may lead to their depletion. Third, the number or sensitivity of postsynaptic receptors may increase, thus depleting neurotransmitter levels.
Depression also may occur as a result of other, yet unknown causes. This condition may be a syndrome that reflects either activity or lack of activity in a number of sites in the brain, including the arousal center (reticular activating system [RAS]), the limbic system, and basal ganglia.
The use of agents that alter the concentration of neurotransmitters in the brain is the most effective means of treating depression with drugs. The antidepressant drugs used today counteract the effects of neurotransmitter deficiencies in three ways. First, they may inhibit the effects of MAO, leading to increased NE or 5HT in the synaptic cleft. Second, they may block reuptake by the releasing nerve, leading to increased neurotransmitter levels in the synaptic cleft. Third, they may regulate receptor sites and the breakdown of neurotransmitters, leading to an accumulation of neurotransmitter in the synaptic cleft.
Antidepressants may be classified into three groups: the tricyclic antidepressants (TCAs), the MAOIs, and the selective serotonin reuptake inhibitors (SSRIs). Other drugs that are used as antidepressants similarly increase the synaptic cleft concentrations of these neurotransmitters.
1. The client is having electroconvulsive therapy for treatment of severe depression. Which of the following indicates that the client’s ECT has been effective?
A. The client loses consciousness.
B. The client vomits.
C. The client’s ECG indicates tachycardia.
D. The client has a grand mal seizure. 2. A client with depression who has been taking amitriptyline for three months returns to the clinic for a follow-up. The nurse observes the client in which of the following symptoms?
A. Suicidal thoughts.
B. Lack of energy.
C. Loss of interest in personal appearance.
D. Neglect of responsibilities.
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答案 Answers
1. D. The client has a grand mal seizure.
During ECT, the client will have a grand mal seize. This indicates completion of the electroconvulsive therapy. Answers A, B, and C do not indicate that the ECT has been effective, so are incorrect. 2. A. Suicidal thoughts.
Clients may have thoughts about suicide when taking an antidepressant such as amitriptyline, especially clients younger than 24 years old. Options B, C, and D are signs of depressions but are most likely improved as the treatment goes on.
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