National Prevalence of Receipt of Antidepressant Prescriptions by Persons Without a Psychiatric Diagnosis

Abstract

Objective

Recent reports have raised concerns about increasing prescription of antidepressant drugs to patients with no recorded mental health diagnosis.

Methods

Using records from 10 large integrated health systems, we examined diagnoses received by health plan members filling at least one antidepressant prescription in 2010.

Results

The most common mental health diagnoses recorded included depressive disorders (47%), anxiety disorders (27%), bipolar disorders (3%), and attention deficit disorders (3%). 39% of those filling antidepressant prescriptions received no mental health diagnosis during the year, but this proportion fell to 27% after excluding antidepressants often prescribed for non-psychiatric indications (tricyclic antidepressants, trazodone, bupropion).

Conclusions

Prescription of antidepressants without appropriate diagnosis appears less common than previously reported.

Approximately 10% of US adults now fill one or more antidepressant prescriptions each year (1, 2) with 75% of these prescriptions are written by non-psychiatrists (1, 3). Recent reports have raised concerns about increasing rates of antidepressant use and have suggested that antidepressants may often be prescribed in the absence of an evidence-based indication. Using data from several large community surveys, Pagura and colleagues reported that 26% of US residents using antidepressant medication did not appear to have any lifetime history of mental health diagnosis (4). Using data from the 2007 US National Ambulatory Medical Care Survey, Mojtabai and Olfson reported that no mental health diagnosis was recorded for over 70% of visits at which an antidepressant was prescribed (5). These data, however, may not provide an accurate picture of indications for antidepressant prescribing. Because past depressive episodes are frequently not recalled (6), community residents with successfully treated depression could be misclassified as having no history of mental health diagnosis. Analyses limited to diagnoses during a single visit might also misclassify those not currently symptomatic.

Here we use data from 10 large health systems to examine diagnoses received by health plan members filling prescriptions for antidepressant drugs. We link prescription and encounter diagnosis data to examine all diagnoses received over a calendar year.

Methods

The Mental Health Research Network (MHRN) is a consortium of public-domain health systems affiliated with large integrated health care systems, including six Kaiser Permanente regions (Georgia, Hawaii, Northern California, Northwest, and Southern California) as well as Group Health Cooperative, Harvard Pilgrim Health Care, HealthPartners, and Henry Ford Health System. The combined populations served by these health systems include approximately 11 million members residing in 12 states. Institutional Review Boards at all sites granted either waivers or exemptions for this use of de-identified medical records data.

Insurance coverage data from each health system were used to identify all members enrolled for at least 10 months during 2010 and having prescription drug coverage during 2010. Those 8,926,781 members included approximately 13% insured by Medicare, 4% by Medicaid, 68% by employer-sponsored insurance, and the remainder insured by individual insurance or other state-sponsored programs.

Combined pharmacy dispensing and claims data were used to identify all members filling one or more prescriptions for any antidepressant drug in 2010. Antidepressant drugs were defined to include all drugs approved by the US Food and Drug Administration for initial treatment of major depressive disorder as well as a few medications not approved for treatment of depression but having substantially similar chemical and clinical effects (e.g. fluvoxamine, clomipramine). Tricyclic antidepressants, trazodone, and bupropion were examined separately as these drugs are often prescribed for non-psychiatric indications (7).

Combined electronic medical record and claims data were used to identify all outpatient or inpatient diagnoses of mental health conditions recorded in 2010. We identified four groups of specific mental health diagnoses for which antidepressants might be prescribed: depressive disorders (ICD9 codes 296.20 through 296.36, 300.4, 309.0, 309.28, and 311), anxiety disorders (ICD9 codes 300.00, 300.01, 300.02, 300.21, 300.22, 300.23, 300.24, 300.3, 309.21, 309.24, and 309.81), bipolar disorders (ICD9 codes 296.00 through 296.06, 296.40 through 296.89, and 301.13), and attention deficit disorders (ICD9 diagnoses 314.0 through 314.9). We also identified those receiving any mental health diagnosis (ICD9 codes 290.0 through 316).

Study Results

As shown in Table 1, the procedures described above identified approximately one million health plan members filling one or more antidepressant prescriptions in 2010. This included approximately 480,000 filling prescriptions for antidepressants often prescribed for non-psychiatric indications (tryicyclic antidepressants, trazodone, or bupropion) and approximately 710,000 filling prescriptions for other antidepressants. Some individuals were included in both groups. Approximately 48% of those filling at least one prescription for any antidepressant drug received at least one diagnosis of any depressive disorder. Approximately 27% received at least one diagnosis of any anxiety disorder, and the proportions receiving diagnoses of a bipolar disorder or attention deficit disorder were approximately 3% each. Approximately 39% received no mental health diagnosis during the year. Across the ten MHRN health systems, the proportion with no mental health diagnosis ranged from 33% to 45%.

Table 1.

Diagnoses recorded for health plan members filling antidepressant prescriptions in 2010.

	Any Antidepressant	Tricyclics, trazodone, and bupropion	All Other Antidepressants	All Other Antidepressants
				Age 0 to 19	Age 20-39	Age 40-64	Age 65+
# filling one or more prescriptions	1,011,946	478,834	712,494	34,258	158,640	385,775	139,452
% with depression diagnosis	48%	42%	59%	60%	59%	57%	65%
% with anxiety disorder diagnosis	27%	23%	33%	49%	44%	30%	24%
% with bipolar disorder diagnosis	3%	4%	4%	6%	5%	4%	2%
# with ADD diagnosis	3%	4%	4%	25%	5%	2%	0.4%
% with no mental health diagnosis	39%	48%	27%	11%	22%	30%	25%

As expected, the proportion of people using antidepressants who received no mental health diagnoses was larger (approximately 48%) for those using trazodone, tricyclic antidepressants, or bupropion than for those using other antidepressants (approximately 27%). This pattern was also similar across the ten health systems (details available on request).

As shown in the right portion of Table 1, the prevalence of specific mental health diagnoses among those prescribed antidepressants did vary by age. As expected, the proportion of patients with attention deficit disorder diagnoses was much higher in children and adolescents (approximately 25%) than among adults. The proportion with no recorded mental health diagnosis also varied by age, ranging from approximately 11% among children and adolescents to approximately 30% among middle-aged and older adults.

Discussion

We find that 39% of health plan members filling antidepressant prescriptions during 2009 received no mental health diagnosis during that year. After excluding antidepressant drugs commonly prescribed for non-psychiatric indications (trazodone, tricyclic antidepressants, and bupropion) the proportion with no mental health diagnosis decreases to only 27% – compared to the 70% with no mental health diagnosis reported by Olfson and Mojtabai (5). We suspect this difference reflects the capture of all diagnoses during a calendar year rather than those from a single visit.

Our methods probably still under-estimate the true rate of mental health diagnoses among those using antidepressants. First, we might not identify mental health diagnoses recorded when treatment was initiated (e.g. diagnoses recorded in late 2008 among patients filling prescriptions in early 2009). Second, we would not identify diagnoses for inpatient or outpatient services that were not provided or covered by the health plan (e.g. services covered by other insurance sources or paid completely out of pocket). Third, prescribing providers may have sometimes recognized or diagnosed depression or another mental health condition but chosen not to record a diagnosis.

In addition, we should emphasize that some antidepressant prescribing for non-psychiatric indications is expected and supported by reasonable evidence. While such non-psychiatric indications may be more common for bupropion, trazodone, and tricyclic antidepressants, FDA-approved non-psychiatric indications do exist for other antidepressants (e.g. premenstrual dysphoric disorder for fluoxetine, pain conditions and fibromyalgia for duloxetine).

The visit diagnosis data available to us cannot assess the severity of mental health conditions. Consequently, we cannot determine what proportion of those receiving depression diagnoses had symptoms of depression or anxiety severe enough to warrant treatment with medication.

These analyses do not evaluate the quality or continuity of care for those receiving antidepressant medication. Previous research suggests that early discontinuation of antidepressant medications is common and that many patients starting antidepressant treatment make few, if any, return visits to the prescribing provider (8-10). This latter scenario (no return visits following the initial prescription) could explain some cases of antidepressant prescription refills not accompanied by any mental health diagnosis.

Significant concerns persist regarding quality of antidepressant treatment – including frequent non-adherence and infrequent follow-up care (11). But frequent prescribing of antidepressants for inappropriate indications is probably not highest on that list of concerns.