As we have gained more knowledge about the functioning of the brain and the key role played by neurotransmitters in that functioning, it has become clear that a variety of psychological disorders, including depression, schizophrenia, various anxiety disorders, and many others, are associated with abnormal levels of speciﬁc neurotransmitters. This has led to some remarkably effective treatments that target receptor sites and reuptake mechanisms for speciﬁc neurotransmitters. Selective serotonin reuptake inhibitors such as Prozac and Zoloft, for example, have proven to be very effective in the treatment of depression as well as several other disorders, simply by increasing the levels of serotonin in key areas of the brain. Psychotic symptoms of schizophrenia are now often controlled quite effectively with antipsychotic medications that alter levels of various neurotransmitters, obviating the need for such old-fashioned tools as the straitjacket, the padded cell, and the lobotomy.
This increased understanding of the role of crucial brain chemical levels has led to widespread use of the term “chemical imbalance” as a sort of shorthand term for the knowledge that a particular person’s disorder may be due primarily to improper neurotransmitter levels. Chemical imbalance is not actually a diagnosis, but the term has become popular among no specialists, who ﬁnd it a convenient way to quickly explain that a particular person’s problem behaviors are due to a medical cause rather than anything deliberate. The trouble with this is that establishing a cause-and-effect relationship based on correlational data is difﬁcult. We know, for example, that lower serotonin levels are found in depressed people than in non-depressed people, but this could be interpreted in either of two ways: low serotonin levels produce depression, or depression causes serotonin levels to drop (solid experimental evidence supports both interpretations). Regardless of the causal direction, clearly raising serotonin levels back up relieves depression, but the effectiveness of cognitive-behavioral therapy with depression suggests that the same result can also be achieved through non-medical means. Attributing mental illness to chemical imbalances may lead to exclusively medical treatment, whereas seeing the imbalance as a symptom leaves us open to examining the effectiveness of a wider range of treatment options. The downside of drug treatment is that no change occurs in behaviors that may be contributing to the disorder, and the person becomes dependent on the drug to keep the symptoms away, so our recognition of the role of chemical imbalances is a bit of a double-edged sword.
- Jensen, J. “Let’s Not Medicate Away Student Angst.” Chronicle of Higher Education, 49(40) (2003): B5.