Understanding Psychology (10th Ed)

 Module 
51 
Biomedical Therapy: Biological Approaches to Treatment 
565
Despite the effectiveness of antipsychotic drugs, they do not produce a “cure” 
in the same way that, say, penicillin cures an infection. Most of the time, the symp-
toms reappear when the drug is withdrawn. Furthermore, such drugs can have long-
term side effects, such as dryness of the mouth and throat, dizziness, and sometimes 
tremors and loss of muscle control, which may continue after drug treatments are 
stopped (Voruganti et al., 2007).
 ANTIDEPRESSANT DRUGS 
As their name suggests,  antidepressant drugs  are a class of medications used in cases 
of severe depression to improve the patient’s mood and feeling of well-being. They 
are also sometimes used for other disorders, such as anxiety disorders and bulimia 
(Walsh et al., 2006; Hedges et al., 2007). 
Most antidepressant drugs work by changing the concentration of specifi c neu-
rotransmitters in the brain. For example, tricyclic drug increase the availability of 
norepinephrine at the synapses of neurons, whereas MAO inhibitors prevent the 
enzyme monoamine oxidase (MAO) from breaking down neurotransmitters. Newer 
antidepressants—such as Lexapro—are selective serotonin reuptake inhibitors (SSRIs) . 
SSRIs target the neurotransmitter serotonin and permit it to linger at the synapse. 
Some antidepressants produce a combination of effects. For instance, nefazodone 
(Serzone) blocks serotonin at some receptor sites but not others, while bupropion 
(Wellbutrin and Zyban) affects the norepinephrine and dopamine systems (see Figure 2 ; 
Lucki & O’Leary, 2004; Robinson, 2007; Dhillon, Yang, & Curran, 2008). 
Finally, there are some newer drugs on the horizon. For instance, scientists have 
found that the anesthetic ketamine blocks the neural receptor NMDA, which affects 
the neurotransmitter glutamate. Glutamate plays an important role in mood regula-
tion and the ability to experience pleasure, and researchers believe that ketamine 
blockers may prove to be useful in the treatment of depression (Skolnick, Popik, & 
Trullas, 2009).