Psychiatric Prescribing Patterns for Depression Treatment in an Outpatient Depression Clinic

Abstract

Objective:

To elucidate psychiatric prescribing patterns for depression treatment in patients being seen by an outpatient depression clinic as of 2018.

Experimental Design:

Single-center, observational analysis.

Principle Observation:

Selective serotonin receptor inhibitors are most commonly used by patients, and the majority of trials have adequate duration (2 months or longer).

Conclusion:

Healthcare providers observed in this study follow depression treatment guidelines and ensure medications are given an adequate trial.

Introduction

Depression is a prevalent disorder that can be challenging to manage with 12% of the population living with major depressive disorder (MDD).¹ While there are guidelines to aid clinicians in treating MDD,² these guidelines are nonspecific—mostly referring to general classes, not individual medications—and ambiguous—presenting multiple options within each treatment step of a flowchart. Better guidance is needed for clinicians making depression treatment decisions.³ Given the broad array of how the guidelines can be interpreted and applied, this brief report aims to elucidate psychiatric prescribing patterns for treatment resistant depression in patients being seen by an outpatient depression clinic as of 2018 with a focus on unique patient-reported responses.

Methods

From January 1, 2018 to June 30, 2018, pharmacy students attempted to reach all new patients seen by University of Michigan Depression Center providers by phone prior to their clinic appointment. The objective was to perform a medication reconciliation and to collect the patient’s depression treatment history for analysis of prescribing patterns and patient medication responses. The process is detailed in a previously published manuscript.⁴ Patient Health Questionnaire (PHQ)-9 scores were also retrieved from electronic medical records. The PHQ-9 score from the first depression clinic appointment within the study period was recorded for patients who completed both medication reconciliation and depression treatment history.

Results

PHQ-9 scores for 100 of the 113 patients were recorded and categorized (Table 1). A logistic regression demonstrated that PHQ-9 scores, age, and sex were not predictive of selective serotonin reuptake inhibitor (SSRI) exposure.

Table 1. PHQ-9 Scores.

Classification (PHQ-9 Score Range)	Number of Patients (n = 100)
None (0–4)	4
Mild (5–9)	19
Moderate (10–14)	27
Moderately Severe (15–19)	31
Severe (20–27)	19

Medication classes with the highest average trials per patient were SSRIs (1.76 trials/patient, total 201 trials), benzodiazepines (BZDs) (0.89 trials/patient, total 101 trials), and ‘other’ antidepressants (0.78 trials/patient, total 89 trials). The most common SSRIs tried by this patient population include sertraline, fluoxetine, citalopram, and escitalopram; the most common benzodiazepines include alprazolam, clonazepam, and lorazepam; the most common ‘other’ antidepressants include bupropion and trazodone. We characterized each trial as either “adequate” (sufficient dose for at least two months)⁵ or inadequate, and show the results by class in Figure 1. For instance, out of the total of 201 trials of SSRIs, 123 were adequate. Monoamine oxidase inhibitors (MAOIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and benzodiazepines had the highest percent of adequate trials (Figure 1).

Figure 1.

Adequate Trials by Medication Class

Patient response to each medication was also analyzed and aggregated into class effects. Of the antidepressants, ‘other’ antidepressants had the highest “worked” rating at 36%, while SSRIs had the highest “didn’t work at all” rating at 51.3%. Tachyphylaxis with SSRIs was reported at a rate of 15% (Figure 2). Stimulants (12.8%), SSRIs (11.9%), and mood stabilizers (11.3%) had the highest rates of patients experiencing multiple side effects. For medication discontinuation due to side effects, mood stabilizers (21.1%), ‘other’ antidepressants (20%), and SSRIs (18.5%) had the highest rates (Table 2).

Figure 2.

Response to Antidepressants

Table 2. Still Taking and Main Reason for Discontinuation.

Still Taking/Discontinued							Main Reason for Discontinuation
		Still taking		Discontinued			Side effects		Worsened mood		No change in mood/Ineffective		Stopped working		Cost		Other		Unknown
SSRIs (n = 205)		17.1% (35)		82.9% (170)			22.4% (38)		3.5% (6)		42.4% (72)		14.1% (24)		0%		7.1% (12)		10.6% (18)
SNRIs (n = 76)		34.2% (26)		65.8% (50)			24% (12)		2% (1)		38% (19)		14% (7)		6% (3)		4% (2)		12% (6)
Other (n = 90)		36.7% (33)		63.3% (57)			31.6% (18)		1.8% (1)		28.1% (16)		8.8% (5)		0%		17.5% (10)		12.3% (7)
TCAs (n = 20)		30% (6)		70% (14)			14.3% (2)		0%		42.9% (6)		35.7% (5)		0%		7.1% (1)		0%
MAOIs (n = 6)		33.3% (2)		66.7% (4)			25% (1)		0%		50% (2)		25% (1)		0%		0%		0%
Atypical (n = 64)		28.1% (18)		71.9% (46)			17.4% (8)		6.5% (3)		43.5% (20)		13% (6)		2.2% (1)		10.9% (5)		6.5% (3)
Typical (n = 2)		0%		100%			0%		0%		0%		0%		0%		50% (1)		50% (1)
Mood Stabilizers (n = 70)		20% (14)		84.3% (56)			26.8% (15)		1.8% (1)		35.7% (20)		10.7% (6)		1.8% (1)		8.9% (5)		14.3% (8)
Stimulants (n = 39)		28.2% (11)		71.8% (28)			21.4% (6)		0%		21.4% (6)		3.6% (1)		7.1% (2)		28.6% (8)		17.8% (5)
BZDs (n = 101)		31.7% (32)		68.3% (69)			8.7% (6)		1.4% (1)		14.5% (10)		4.3% (3)		2.9% (2)		44.9% (31)		23.2% (16)

Discussion

According to the data collected, SSRIs were by far the most commonly used by patients, which follows treatment guidelines. Whether or not the SSRIs were prescribed first could not be determined; however, it is promising that first line treatment is the most commonly used class among those studied. This aligns with the results of the logistic regression.

Additionally, the majority of the medication trials in all but one class were adequate in duration. This is valuable, yet surprising, as in another study only 153 of 453 patients with MDD were continuously treated for at least 2 months.⁶

This report offers a unique perspective by including patient-reported response to medication. No other studies were found to present the patient perspective on how well a medication worked, as most use formal surveys to measure effectiveness, such as the Hamilton Depression Rating Scale, and assess quality of life and symptom severity. For the “worked but stopped after awhile” response to SSRIs, patients reported a lower tachyphylaxis rate (15%) than another study, which found a symptom recurrence of 33.7%.⁷ In contrast, the 51.3% response rate of “didn’t work at all” is higher comparatively, as one study published that 37.5% did not respond to an SSRI.⁸ Another study states that while some SSRIs are more effective than alternative antidepressants, other SSRIs are among the least effective antidepressants.⁹ This coincides with the results of both a lower tachyphylaxis rate and higher “didn’t work at all” response rate for SSRIs.

Many connections can be made between rates of use, side effects, and discontinuation due to side effects. SSRIs and mood stabilizers have two of the three highest rates of multiple side effects and discontinuation due to side effects, yet SSRIs are most common. In contrast, benzodiazepines have one of the lowest side effect rates and are second most commonly used.

This report highlights how outpatient depression medications are being prescribed. All data was obtained through patient reporting. This is the most relevant form of data abstraction for clinical practice, as this is the method prescribers use to obtain information during a patient appointment.

The primary limitations and future directions of this data coincide with those of the previously published manuscript.⁴ Ultimately, the data is limited by the number of patients and the lack of a time reference for medication use. Moving forward, more patients could be reached by creating an online form for convenience. Also, a timeline could be integrated into the depression treatment history to provide a reference for the order in which medications were tried and in what combinations. Specifically, it could then be determined whether or not SSRIs had been used as first line treatment as according to the guidelines. Further studies can also investigate the dose of medications in order to determine further adequacy of medication trials.

Conclusion

According to reports ascertained directly from patients, providers prescribe SSRIs the most frequently, aligning with depression treatment guidelines, but they also ensure that the majority of the medications for depression are given an adequate trial. These are two key points in the efforts of addressing treatment-resistant depression.