This study's findings have some interesting implications, particularly when placed in the context of prior work on Latino mental health. This section notes a few implications and discusses the study's limitations.
One third of those who used antidepressants within the past year had discontinued all antidepressants at the time of interview. This rate is outside the range of discontinuation rates reported in Lingam and Scott's review,14
which concluded that between 45 and 60% of patients stop taking prescribed antidepressants within 3 months of starting. However, the rate in this study is not strictly comparable to their rates, as respondents were not followed from the time of starting medication, as in a cohort study. Some NLAAS respondents may have only just started antidepressant use at the time of interview (biasing the discontinuation rate downward), while others who report having stopped may have taken antidepressants for six months or more (an upward bias). The net effect of these biases is not clear.
The finding that 18.9% of respondents who discontinued did so without prior medical input is a rate similar to results from another survey-based study examining compliance. That study reported that 24% of patients did not inform their physician about stopping the antidepressant medication, and found that the likelihood of patients’ informing their providers varied according to the patients’ perceptions of the treatment relationship and to their reasons for discontinuing.26
This study's relatively high rate of respondents who discontinued with prior medical input is particularly concerning given the clinical risks associated with discontinuing antidepressants abruptly.53,54
A recent consensus panel recommended that management strategies include gradual tapering of doses, with clinical monitoring and patient education.55
It is noteworthy how much more likely uninsured individuals are to discontinue treatment, compared to those with some form of health insurance. This could relate to the price of the drugs themselves, which is high for an individual paying out-of-pocket, particularly for newer drugs. But it is worth pointing out that the uninsured people in this sample did report having used at least one antidepressant, so price was not a consistently insurmountable barrier. It is also possible that their lack of insurance led to prescription of less expensive medications which proved harder to tolerate, or that it made them unable or unwilling to receive concurrent therapy or medical visits that might otherwise have discouraged discontinuation. Latinos are known to be considerably more likely to be uninsured than other ethnic groups,56
and more than twice as likely to be uninsured as non-Latino whites (19.4% vs. 41.6%).57
The results supported the study hypotheses regarding the potential importance of sociocultural factors, in particular English proficiency. Differences commonly exist between what providers recall communicating to patients and what patients report being told,15
and this discrepancy may be greater for Latinos experiencing a language barrier. Enhanced English proficiency presumably aids both patients’ ability to communicate their adherence concerns and physicians’ ability to be adequately responsive. Further, given that Latinos tend to prefer non-pharmacologic treatment modalities58
and to be significantly less likely than non-Latino whites to find antidepressant medications acceptable,59
there may be an even greater need for prescribing physicians not only to discuss attitudes, beliefs and fears (e.g. of addiction) with their Latino patients but also to strengthen these patients’ understanding of how persistence with a medication regimen is likely to ease suffering substantially without risk of addiction.
It is striking that two of the three clinical variables included did not attain statistical significance. The variables for problem recognition and role functioning were expected to relate more closely to the patient's own experience than diagnostic measures, and therefore be correlated with discontinuation. However, the only clinical variable that predicted discontinuation was the number of symptoms of major depression, with more symptoms making discontinuation less likely.
The finding that having at least eight visits with a nonmedical therapist is significantly associated with patients being less likely to stop taking their medications without prior medical input is consistent with expectations. The treatment relationship with a nonmedical therapist may include adherence-related discussions that support communication with the prescribing physician. However, what can be concluded is limited. It may be that those patients receiving combined treatment, counseling and medication, are more comfortable with negotiating their psychiatric care, and/or more motivated to persevere. They may also be more severely depressed, but this would only bias results if depression severity was not captured by the symptom count variable.
The finding that receiving antidepressant medication from a psychiatrist was not associated with lower rates of discontinuation was surprising given the assumption that compared to primary care physicians, these specialist providers may be more likely to be experienced in psychopharmacology, and in optimizing dosing levels and tailoring medication regimens. The finding that respondents were less likely to discontinue if their medications were in the SSRI (vs. tricyclic) class is expected given the greater degree of tolerability coupled with greater convenience associated with these antidepressants.
In conclusion, it is worth noting some limitations to this study's findings. First, it is not known how much of the discontinuation observed was premature, since the data do not reveal how long each respondent was taking antidepressants before discontinuing. The simple extent of discontinuation may nonetheless be of interest. Second, for respondents who took more than one medication, we do not know whether these were concurrent, or if not, in what sequence they were taken. However, in practice 80% of the sample only took one medication, 16% took 2 and 3% took 3 or more, so the proportion affected is relatively small.
Third, this study relies on respondents’ reporting on whether they discontinued antidepressants with or without prior medical input. In some cases, providers may disagree with the respondent's report regarding their input. There may be respondents who feel uncomfortable admitting to discontinuing their medications without physician input or knowledge, or even against the physician's recommendation, which could make the actual ‘without prior medical input’ category higher. There may also be cases where patients discontinued their antidepressants independent of the physician, did not communicate with the prescribing provider – particularly in the case of primary care – for several months, then informed the provider of the earlier discontinuation only at a later point, when the patient was experiencing recovery. At such time, the provider may well offer agreement with the earlier decision to discontinue, particularly if the patient had decided to substitute psychotherapy or another therapeutic modality instead, one which proved beneficial. After-the-fact agreement is of course distinct from that given at the time of discontinuation, but respondents in the above scenario might feel comfortable responding affirmatively to the question of whether their physician agreed with their decision. Again, the actual ‘without prior medical input’ category would expand if one were able to distinguish such cases.
A third limitation is the relatively small sample size for this particular question, since the study is limited to antidepressant users. This reduces the study's ability to detect moderate sized effects, and also impedes analysis of subgroups such as the different Latino ethnicities. The results may nonetheless be helpful in the design of further research.