Most Americans with depressive and anxiety disorders do not receive mental health care in the form of antidepressant treatment according to our findings. Above and beyond the lack of care for depressive and anxiety disorders facing Americans, we found marked differences in antidepressant use between Latinos and non-Latino Whites. Specifically, Mexican Americans, who represent over two thirds of Latinos in the United States,[
4] are also the most likely to encounter differences in antidepressant use. Nationally, fewer than one-in-four Latinos or about 1.3 million of the estimated 6.4 million with depressive or anxiety disorders have received antidepressant treatment. Our findings highlight the importance of disaggregating Latinos by ethnic subgroups for pinpointing where treatment inequalities exist within the diversity of Latinos in the US. Ignoring the different experiences of Latino subgroups with mental health-care access masks important treatment use differences between major Latino subgroups, namely Mexican Americans and non-Latino Whites.[
3,
17] Our approach provides evidence for improving mental health care to those Latinos facing the most problems with treatment availability.
Latinos face many barriers to adequate mental health care.[
18] We found evidence that suggests immigrants with less acculturation were less apt to use antidepressants more than their acculturated counterparts. Furthermore, the differences in antidepressant use were not accounted for by other important factors related to better access to care. Outpatient primary care has become the de facto mental health system for most Americans where recognition and treatment of depressive and anxiety disorders are often challenging for busy clinicians working with any racial and ethnic groups. As reported for Black Americans,[
19] it is possible that primary-care physicians serving Latinos may have less training and access to additional clinical resources and psychiatric specialists as do physicians serving White patients. Another explanation for the findings in this study could reflect lower acceptability of antidepressants by Mexican Americans.[
20] Additionally, cultural differences between White clinicians and Latino patients may affect symptom communication, recognition, and subsequent treatment, and could explain the low prevalence of antidepressant use by specific Latino groups.[
21] Cultural differences may account for the frequency of antidepressant use among respondents without depressive or anxiety disorders. Factors contributing to the treatment inequalities for Mexican Americans, we found, will require additional in-depth study to understand and achieve parity.
The majority of Latinos and non-Latino Whites using antidepressants did not meet diagnostic criteria for 12-month depressive and anxiety disorders. Lifetime depressive and anxiety disorders explained an additional 21% of past year antidepressant use. Our findings are consistent with those of Druss et al. who found that individuals who met criteria for lifetime mental disorders, but not current 12-month disorders, accounted for a considerable proportion of current 12-month mental health services use.[
8] This may be indicative of treatment maintenance to prevent relapse for patients with these mental disorders. Nevertheless, 12-month and lifetime depressive and anxiety disorders did not account for nearly one third of all the antidepressants use in this national sample. Medical conditions associated vascular disease, particularly diabetes and hypertension, increased the odds of antidepressant use independent of lifetime mental disorders. Antidepressants are commonly prescribed for diabetic neuropathy and sleep problems. It may be that antidepressants are being prescribed for mood changes associated with vascular disease.[
9,
22] The reasons for the other uses of antidepressant medications may require further in-depth investigation.
The antidepressant prevalence estimates reported herein are unique in that the CPES is a nationally representative household sample. Respondents were selected into the sample regardless of medical-care access, a feature that is distinct from earlier reports based on clinical records and medical claims data.[
23] This is a particularly important feature of this study in understanding the low use of antidepressants by Latinos. For example, over 40% of Mexican Americans lack medical insurance, which can limit their access to health care.[
4] Estimates of unmet need for antidepressant treatment that are established in community samples, without necessarily requiring that the sample have access to care (as in the case of medical claims samples) are critical to understanding the health needs of this population. Secondly, antidepressant medication use in this study was determined by both self-report and pill bottle inventories. Pill bottle inventories limits underreporting drugs that were not recognized by respondents as psychiatric medications. Because of these two study characteristics, we believe that the prevalence of antidepressant use reported herein are likely to be the most accurate and ethnically specific national estimates to date.
Our results should be interpreted in the context of several limitations. First, the CPES excluded those who were homeless or institutionalized and may not completely define the current need for depressive and anxiety disorders treatment in the US. Second, systematic survey nonresponse and nonreporting could lead to underestimates of the degree of unmet need.[
10] Third, as a diagnostic instrument for Latinos, the WMH-CIDI has modest test characteristics for detecting psychiatric disorders (e.g., major depression), but was highly accurate for excluding cases without psychiatric conditions. Thus, it is possible that some cases with “true” psychiatric disorders were missed, which could have inflated the proportion of Latinos without psychiatric disorders using antidepressants. Additionally, antidepressant users may have had a depressive or anxiety disorder that was in remission, and thus may have overlooked or underreported their symptoms. This potentially could have increased our estimates of antidepressant users who did not meet 12-month criteria for disorders (i.e., false negatives). Nevertheless, our findings that the mental health needs of Latinos are mostly unmet and that many Latinos without psychiatric disorders utilize antidepressants are consistent with previous clinic-based research.[
23,
24] Given the magnitude of unmet need that we observed, the main inferences of our work would be unlikely to change dramatically.
This research suggests several directions for future research and policy to improve delivery of mental health care for all Americans, but especially for Mexican Americans who are the largest and most underserved group of Latinos. First, increased availability and initiation of treatment with mental health needs will require new evidence-based outreach efforts. One clear example of a cost-effective approach for improving mental health care is the collaborative primary care of depression model.[
25,
26] Because mental disorders can be difficult to detect in the limited time available to most primary-care physicians, such a model may provide the specialists needed for detecting and treating common psychiatric disorders, particularly in the presence of comorbid medical conditions. Second, continued attempts to lower cross-cultural communication barriers between patients and care-providers may improve diagnoses and ensure the delivery of appropriate treatments.[
27] Although new financing and treatment resources will undoubtedly be required, monitoring those costs in relation to possible savings will be important to evaluate for effectiveness. Third, better interventions are required to ensure treatment to those most in need. Revised performance indicators that include structured diagnostic assessments represent one possible mechanism. If successful, these types of interventions may indirectly remove barriers to care.[
25] Finally, new research is required that explores the potential value of antidepressant treatment in medical conditions other than depressive and anxiety disorders.