In outpatient psychiatric practice, psychiatrists use long-acting antipsychotic injections to manage fewer than 1 in 5 patients with schizophrenia having episodes of medication nonadherence. Although consideration of long-acting antipsychotic injections is recommended for patients with a history of problems with adherence on oral medication,6
most patients in this nationally representative community sample who were not adherent with oral antipsychotic medications were not prescribed long-acting antipsychotic injections. The relatively low rate of use is broadly consistent with previous research.2,7
The clinical decision to initiate injection antipsychotic medications appears to rest on a clinical assessment of the risks and consequences of poor medication adherence. Patients at greater risk, specifically those who have a history of persistent nonadherence and those admitted for inpatient care during their last episode of nonadherence, were more likely to be started on injections. However, some patient groups at high risk for recurrent medication nonadherence, such as patients who live alone and younger patients,1
had surprisingly low levels of injection use.
Depot antipsychotic medications are not widely used beyond those who are publicly insured or treated in residential or inpatient facilities. These settings presumably have staff members to facilitate delivery of depot antipsychotics and cater to the more severely ill. Innovative strategies to train more psychiatrists and their staff in the use of depot antipsychotics may help promote their use in different settings and in patients who are less severely ill but are still medication nonadherent. In general, adoption of technologies that vary from current or typical practices face significantly greater challenges in diffusing into practice, than those that rely on existing practices.9
For this reason, greater opportunities for first-hand observation and hands-on training may be needed. One approach is to set up specialty long-acting antipsychotic injection clinics in private and public outpatient settings that accept referrals. Mobile outreach services provide another option for delivering long-acting injections.10
Use of long-acting antipsychotic medications was uncommon among patients prescribed antidepressants or mood stabilizers just prior to the start of the last episode of antipsychotic nonadherence. Some psychiatrists may perceive that the marginal benefit of a long-acting antipsychotic injection is diminished when it does not obviate the need for oral medications as is the case when several classes of oral psychotropic medications are prescribed. In light of the frequency with which schizophrenia patients receive complex regimens involving oral medications other than antipsychotic medications,11,12
this diminishing benefit of depot medications may also hinder use of newer long-acting antipsychotic preparations.
Cognitive impairment has been linked to treatment nonadherence among psychotic patients (review13
). Although cognitively impaired patients may have a limited ability to take oral medications on their own, patients assessed as having lower than average intelligence were (after controlling for several potential confounds) significantly less likely to receive depot antipsychotic medications than were those of at least average intelligence. These results suggest that efforts are needed to improve access of depot antipsychotic medications to cognitively impaired patients.
In many but not all health care contexts,14–17
patients with private insurance enjoy greater access to evidence-based treatments than publicly insured patients. For long-acting antipsychotics, patients with private insurance were less likely than publicly insured patients to receive treatment. This may reflect greater access to long-acting injections in organized treatment settings than in office-based settings favored by privately insured patients or a stronger preference for oral second-generation antipsychotics among privately insured patients. With the availability of long-acting injectable risperidone, the difference in rate of use by publicly and privately insured patients may narrow.
Psychiatrists who were more optimistic about the effectiveness of managing medication nonadherence were more likely to treat their patients with depot antipsychotics. Psychiatrists who prescribe injections may have had more opportunities to observe favorable patient outcomes than do psychiatrists who do not prescribe these preparations.18
In this study, greater knowledge of depot medications was in turn related to more favorable attitudes toward these medications. Consequently, educational efforts to expand use of depot antipsychotics might be preferentially targeted to psychiatrist groups with low rates of use.
After controlling for several potentially confounding factors, female psychiatrists were significantly more likely to treat their medication nonadherent schizophrenia patients with depot antipsychotic medications than were their male and white counterparts. In one survey of British psychiatrists, more favorable patient-centered attitudes were reported by psychiatrists with higher depot use,19
and in some contexts female as compared with male physicians have been found to engage in a more patient-centered style of communication.20
Whether gender-related differences in communication style or other factors account for the psychiatrist gender difference in use of depot antipsychotic medications remains unknown.
The use of depot antipsychotic medications was not significantly related to patient age, gender, or race/ethnicity. Previous studies of psychotic patients that are not selected for recent medication nonadherence have reported that use of depot antipsychotic medications is significantly more common among males,21,22
and younger patients.25
Because these demographic characteristics also increase the risk of antipsychotic medication nonadherence (reviews1,26
), it is perhaps not surprising that they are not significantly related to depot antipsychotic use among patients selected for recent medication nonadherence.
This study is constrained by several limitations. First, we relied exclusively on psychiatrist-reported data without independent validation of nonadherence. Because mental health professionals may fail to detect antipsychotic nonadherence,27
depot medications may be more underutilized than the current data suggest. In addition, although the study was limited to patients who had been under the psychiatrists’ care for at least 1 year, the respondent psychiatrists likely vary in their knowledge of the patients. For example, the reliability with which some psychiatrists rated variables such as living situation or family contact may be variable. Second, because the first second-generation long-acting injection was approved by the Food and Drug Administration for marketing when this study was in the field, no information is provided on long-acting risperidone injections. Third, no information was collected concerning the offer of injection. Although available evidence suggests that patients tend to have a positive attitude toward depot antipsychotic medications,28
we do not know the extent to which study patients with medication nonadherence were offered but refused depot antipsychotic medications. Fourth, although psychiatrists were specifically instructed to report on the last patient that they saw who met the study criteria, it is possible that patient selection was biased by protocol violation. Because the survey (management of medication nonadherence) was oriented around management of medication nonadherence, psychiatrists may have tended to select patients who received more active forms of management such as initiation of depot antipsychotic medications. Finally, psychiatrist nonresponse opens the study to the possibility of selection bias at the level of the participating psychiatrist.
With the introduction of injectable long-acting risperidone, it will be important to track the extent to which patients and psychiatrists become more willing to utilize depot preparations and to assess changes in factors that influence these decisions. Early clinical research indicates that medication nonadherence with oral antipsychotic medications is the most common reason for initiating risperidone long-acting injections,29–33
that poor prior antipsychotic adherence predicts greater improvement on risperidone long-acting injections,33
and that patients who are switched from another depot are much less likely to discontinue risperidone long-acting injections than those switched from oral antipsychotic medications.34
These findings suggest that factors which have influenced use of the older depot antipsychotic medications may continue to play a role in medication management decisions with the newer injectable antipsychotic preparations.