Current and Emerging Treatments to Address Unmet Needs in MDD

CME Background Information

Supported by an educational grant from Alkermes, Inc.

Participants may receive credit by reading the activity, correctly answering the posttest questions, and completing the evaluation.

Objectives

After completing this educational activity, you should be able to:

• Assess patients with standardized tools to identify inadequate response to antidepressant therapies
• Select next-step therapies for patients with treatment-resistant depression, informed by current pharmacologic understanding

Financial Disclosure

The faculty for this CME activity and the CME Institute staff were asked to complete a statement regarding all relevant personal and financial relationships between themselves or their spouse/partner and any commercial interest. The CME Institute has resolved any conflicts of interest that were identified. No member of the CME Institute staff reported any relevant personal financial relationships. Faculty financial disclosure is as follows:

Dr Thase is an advisor/consultant to Acadia, Akili, Alkermes, Allergan (Forest, Naurex), Cerecor, Fabre-Kramer, Gerson Lehrman Group, Guidepoint Global, Johnson & Johnson (Janssen, Ortho-McNeil), Lundbeck, Mocksha8, Nestlé (PamLab), Neuralstem, Novartis, Otsuka, Pfizer, and Sunovion; has received grant support from Acadia, Agency for Healthcare Research and Quality, Alkermes, Allergan, Assurex, Avanir, Axsome, Intracellular, Johnson & Johnson, National Institutes of Health/National Institute of Mental Health, Otsuka, Patient-Centered Outcomes Research Institute, and Takeda; has received royalties from American Psychiatric Association Foundation, Guilford Publications, Herald House, and W. W. Norton & Company. Dr Thase’s spouse is employed by Peloton Advantage, which does business with most major pharmaceutical companies.

Accreditation Statement

The CME Institute of Physicians Postgraduate Press, Inc., is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

Credit Designation

The CME Institute of Physicians Postgraduate Press, Inc., designates this enduring material for a maximum of 1.0 AMA PRA Category 1 Credit™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

The American Academy of Physician Assistants (AAPA) accepts certificates of participation for educational activities certified for AMA PRA Category 1 Credit™ from organizations accredited by ACCME or a recognized state medical society. Physician assistants may receive a maximum of 1.0 hours of Category I credit for completing this program.

To obtain credit for this activity, study the material and complete the CME Posttest and Evaluation.

Release, Review, and Expiration Dates

This brief report activity was published in December 2018 and is eligible for AMA PRA Category 1 Credit™ through December 31, 2020. The latest review of this material was October 2018.

Statement of Need and Purpose

Many clinicians do not regularly incorporate standardized tools into the clinical management of major depressive disorder (MDD). Assessing patients for unresolved symptoms is crucial for identifying when a change in treatment is needed. Because most patients do not reach remission from MDD with their initial treatment, physicians usually must use next-step strategies. Our audience of psychiatrists and other mental health care professionals may not be fully aware of the mechanisms of action of current treatments for MDD, based on their reported discomfort with the topic. Clinicians need education about the usefulness and efficiency of MDD assessment tools and how to explain their use to patients. Education is also needed about when to alter the treatment plan. Physicians need guidance on strategies for helping patients who have inadequate response to antidepressant therapy. Treatment selection should be based on a patient’s individual clinical characteristics and the mechanism of action, efficacy, and side effects of treatment options. Physicians also should be aware of emerging MDD treatment targets. This activity was designed to meet the needs of participants in CME activities provided by the CME Institute of Physicians Postgraduate Press, Inc., who have requested information on MDD.

Disclosure of Off-Label Usage

Dr Thase has determined that lithium, thyroid hormone, risperidone, ketamine, esketamine, rapastinel, brexanalone, allopregnanolone, and ALKS 5461 are not approved by the US Food and Drug administration for the treatment of major depressive disorder.

Review Process

The faculty discussed the content at a CME planning session, agreed to provide a balanced and evidence-based presentation, and reviewed the activity for accuracy, and a member of the External Advisory CME Board who is without conflict of interest reviewed the activity to determine whether the material is evidence-based and objective.

Acknowledgment

This Brief Report is derived from the planning teleconference series “Current & Emerging Treatments to Address Unmet Needs in MDD,” which was held in June and July 2018 and supported by an educational grant from Alkermes. The opinions expressed herein are those of the faculty and do not necessarily reflect the opinions of the CME provider and publisher or the commercial supporter.

Over 16 million American adults reported at least 1 episode of major depressive disorder (MDD) in the previous 12 months, according to recent NIMH data, and 64% of these adults experienced severe impairment.¹ Despite the recommended goals of MDD treatment to help patients achieve remission and functional recovery,² only about one-third of patients attain remission from initial treatment.³ For clinicians, this means that most patients require additional treatment steps. The NIMH notes that no one-size-fits-all treatment strategy is available,⁴ and clinicians must make therapy decisions on an individual basis.

Unmet needs for patients with MDD include greater efficacy of antidepressants versus placebo, faster onset of action, better tolerability, efficacy for symptoms such as anxiety and sleep problems, and better alternatives are needed for those with treatment-resistant depression (TRD).^5,6 This activity will explore the identification of TRD, the management of TRD, and emerging treatments for MDD.

Identification of TRD

Definitions. Response to antidepressant treatment typically means that the patient has a 50% or more reduction in symptom intensity or severity over 6–8 weeks of treatment.⁷ However, nonresponse is not as easy to define because it represents a spectrum from failing to achieve minimal response (eg, < 25% decrease from baseline score on a rating scale) to failing to achieve remission (free of depressive symptoms).⁷ For example, the outcomes of patients treated with citalopram in the STAR*D study⁸ showed that almost half achieved response (47%), but only about one-third achieved remission.

Tools. Tracking symptoms using assessment tools is an important step for clinicians to determine patients’ level of response and their sense of symptom intensity. Tools that are useful in clinical practice include the 9-item Patient Health Questionnaire (PHQ-9) and the 16-item Quick Inventory of Depressive Symptomatology–Self-Report (QIDS-SR).⁹ These scales are free to administer, reliable, and sensitive to change. For both of these scales, a 50% reduction corresponds to the level of symptom relief that most patients need to reach to feel that a treatment really works; low scores (≤ 5) correspond to the concept of remission (ie, few or no symptoms).

Patients have said that the use of a standardized tool by their physicians made them feel that they were being listened to and taken seriously during the consultation.¹⁰ A patient described how the physician discussed the rating scale:

Patient Perspectives

“He said that it would help both him and I to be able to, like, almost…take the temperature of how…how great or small the depression was.”¹⁰

Predictors. For patients with TRD, the predictors of nonresponse generally include complexity and chronicity. Substance misuse and addictions are associated with both a greater risk of chronicity and a lower chance of responding to antidepressant medications. A multicenter European study⁶ that examined the clinical features associated with TRD found that recurrent episodes, clinical severity, more than 1 prior hospitalization, suicidality, personality disorder, early age at onset, comorbid anxiety (eg, social phobia, panic disorder), and nonresponse to first antidepressant were all predictors of treatment resistance. A recent study¹¹ found that the incidence of TRD varied from 13% to 31% depending on varying definitions of TRD, but regardless of definition, greater illness severity was a predictor.

Staging models. One system for staging, or grading, the degree of treatment resistance is according to the number of failed treatment trials of different classes of antidepressants. When an antidepressant has not had the desired effects, the stages to be followed progress from simpler strategies (ie, switching to an alternate monotherapy) to more complex strategies (ie, trying combination or augmentation regimens), with the nonselective MAOIs and ECT typically reserved for later stages (AV 1).¹²

AV 1. Staging Model for Treatment-Resistant Major Depressive Disorder (00:51)

Based on Gelenberg et al.² and adapted with permission from Thase and Rush¹²

While there is some controversy about whether the simple staging system actually works well enough to use in practice, evidence suggests that the greater the number of adequate treatment trials that have not succeeded, the lower the patient’s chance for success with the next treatment trial. The STAR*D study^3,8,13 demonstrated this progressive resistance. With each nonresponse to a prospectively administered treatment, some patients were lost to attrition—people dropping out because they felt dissatisfied with the treatment process. The chance of remission also decreased with each successive treatment trial.¹⁴

Management of TRD

The clinical management of patients with TRD should include relatively frequent (eg, biweekly) visits to monitor symptomatic outcome, adjust medications, minimize side effects, and provide clinical support to lessen demoralization and pessimism.² When it is not possible to see patients this frequently, telephone check-ins and secure e-mail contacts can be helpful.

Try to get patients active (eg, problem solving, spending time with people who care, engaging in light aerobic exercise) if possible.² Likewise, encourage patients to adhere to stable/consistent sleep-wake schedules. Have them keep track of other behaviors that may interfere with therapeutic effects, such as drinking or drug use (both prescribed and illicit), including tobacco and marijuana. On more than a few occasions, alcohol or chemical dependence treatment may be needed in combination with more conventional therapies for TRD.

Due to the similar effectiveness among antidepressants,¹⁵ guidelines have advised clinicians to select initial treatment based on side effect profile.^2,16 The most prescribed antidepressants are SSRIs and SNRIs,¹⁷ which typically have favorable side effect profiles, but these agents may not meet the needs of patients with heterogeneous symptom constellations. To manage these patients, clinicians may use switch, augmentation, or combination strategies.¹⁸

Switch. The best reasons for switching are when the patient experiences intolerable side effects or no response with the first antidepressant.² Switching antidepressants is a good strategy for an otherwise uncomplicated patient who is not disabled by depressive symptoms. The second drug selection is guided by how similar or dissimilar it is to the first drug. Clinicians should consider switching to a medication with a different mechanism of action after an initial treatment fails.

One review¹⁹ found evidence to support switching from an SSRI to venlafaxine (5 positive trials out of 6), a TCA (2 positive trials out of 3), or an MAOI (2 positive trials out of 2) but not from an SSRI to bupropion, duloxetine, or mirtazapine. Switching from a TCA to another TCA provides only a modest advantage (response rate of 9%–27%), while switching from an SSRI to another SSRI is more beneficial (response rate of up to 75%). One patient reported success with TCAs after switching from other classes:

Patient Perspectives

“I gave up on the SSRIs and SNRIs after trying nearly all of them and having little to no improvement while taking them. I have since moved on to the tricyclic antidepressants. Specifically, nortriptyline and then imipramine. I consider them to be the heavier industrial grade quality medications that get down to brass tacks and they work for me. Of course, everyone is different but it is incredibly important to know what all of your options are when it comes to fighting depression.”²⁰

Augment. Another option for addressing TRD is augmenting an antidepressant with a medication that is not an antidepressant.² If the initial treatment was partially effective, adjunctive therapy has the advantage of retaining the benefits while adding other mechanisms of action to target specific symptoms. Adjunctive therapy can provide more rapid benefit than switching medications due to avoiding a washout/titration period.

Common adjunctive agents include antipsychotics, lithium, and thyroid hormone.^2,19 The class of adjunctive therapies with the best evidence for benefit is the SGAs.²¹ Antipsychotic drugs that have received FDA approval as adjunctive treatment of TRD include aripiprazole, quetiapine, olanzapine (with the SSRI fluoxetine), and brexpiprazole.²²

A meta-analysis²³ of SGA augmentation trials included olanzapine, quetiapine, risperidone, and aripiprazole. Results showed that the adjunctive SGAs were significantly more effective than placebo (response: odds ratio = 1.69, P < .00001; remission: odds ratio = 2.00, P < .00001). The mean odds ratios did not differ among agents. Discontinuation due to adverse effects was higher for the SGAs than placebo.

When weighing the potential risks and benefits of SGAs, clinicians should consider the patient’s age, weight, body mass index, and medical history and the family history of diabetes and cardiovascular diseases. Clinicians must regularly monitor patients for adverse effects, including metabolic side effects (eg, weight gain, dyslipidemia, diabetes), EPS, and tardive dyskinesia.²⁴ Length of treatment and cost effectiveness are important questions when considering adjunctive SGAs.^2,22

Combine. A third alternative for managing TRD is adding another antidepressant or depression-focused psychotherapy to the initial antidepressant.² As with augmentation, this treatment step is ideal if the patient has had some benefit from initial therapy but has either side effects or residual symptoms that need to be targeted. Disadvantages compared with switching treatments include potentially decreased adherence, more adverse effects, and greater cost due to having more medications.²⁵

Common combinations include bupropion with an SSRI, and mirtazapine with antidepressants of different classes,^2,19 but no antidepressant has FDA approval as a combination strategy in TRD.

The evidence from well-controlled studies of combining antidepressants is not strong. In the CO-MED study,²⁶ no evidence supported the combination of bupropion with escitalopram or of venlafaxine with mirtazapine, compared with escitalopram alone. Remission and response rates were not significantly different, and patients taking the venlafaxine/mirtazapine combination had increased adverse effects.²⁶

However, a study by Blier and colleagues²⁷ found evidence of benefit for 3 antidepressant combinations with mirtazapine (fluoxetine, venlafaxine, and bupropion) versus fluoxetine monotherapy. Remission rates ( ≤ 7 on HDRS) were 25% for fluoxetine alone, 52% for mirtazapine plus fluoxetine (P = .05), 58% for mirtazapine plus venlafaxine (P = .05), and 46% for mirtazapine plus bupropion.

The difference in study results could be due to the maximum doses being used by Blier and colleagues versus the more modest doses used in CO-MED to spare side effects. Both studies used combined antidepressants for first-step acute treatment rather than in patients who had failed 1 or more trials.

Comparison of switching, augmentation, and combination strategies. The STAR*D study did not show differences in rates of response and remission or time to response and remission between switching, augmentation, and combination strategies.^28,29

AV 2. Results From the VAST-D Clinical Trial (N=1,522) (00:33)

Data from Mohamed et al.³⁰

The large VAST-D study,³⁰ which included patients with MDD (n = 1,522) who had no response to at least 1 adequate antidepressant trial, examined 3 interventions for 12 weeks: switch to bupropion, augmentation with bupropion, and augmentation with aripiprazole. The remission rate for augmentation with aripiprazole (28.9%) was significantly greater than for switching (22.3%; P = .02), but adverse effects that were more frequent included somnolence, akathisia, and weight gain (AV 2).³⁰

Higher-level resistance. For some patients, MAOIs may provide benefits where other therapies fail.² Tranylcypromine had poor tolerability and efficacy in STAR*D patients who had failed 3 previous treatment trials,¹³ but MAOIs have proven efficacy in patients with anergic bipolar depression, anxiety, atypical depression, and TRD.³¹ For example, response rates of 59% to 71% have been reported in patients with atypical depression taking MAOIs.³² However, MAOIs are typically reserved as later treatment options due to safety and tolerability concerns and the need for dietary restrictions with some formulations.³¹ A washout period is required before and after using an MAOI to avoid serotonin syndrome.²

One patient described how an MAOI was the treatment that finally helped him with TRD:

Patient Perspectives

“I was on many different combinations before the [psychiatrist] considered me as treatment resistant. The SSRIs would work for a while, then either slowly quit working or overnight they would drop me back into the pit of depression. I…was considering ECT. The [psychiatrist] thought I should try a MAOI first. That has made a difference in me for almost 10 years now.”²⁰

A treatment option for patients who fail numerous medication trials is ECT, which has demonstrated high rates of response and remission.² This treatment modality is infrequently used because of stigma and concerns about adverse effects and cost. Recent simulation evidence suggested that ECT is more cost-effective than ongoing trials of antidepressant therapy after 2 treatment failures.³³

ECT is first-line treatment for patients with depression who have psychotic features or are catatonic, suicidal, in nutritional jeopardy due to refusing food, or hospitalized.² ECT tends to achieve response rates of 50% to 70% in patients with TRD.³⁴

One patient described his experience with ECT in the following post

Patient Perspectives

“I’ve had ECT a number of times and would recommend it (if I had to have it again I would because it was literally lifesaving on both occasions). There is some short-term memory loss, but my memory came back and I can now recall everything including from the times I actually had ECT. It is painless and relatively safe. All I had left over from the day of treatment was a slight headache and tiredness from the anesthesia.”³⁵

AV 3. Feelings and Outcomes of Patients With Depression Who Experience Inadequate Response (00:56)

Data from Mago et al.³⁸

However, ECT carries significant risk of relapse and recurrence in patients who have no effective post-ECT intervention plan,³⁶ especially those who are placed on maintenance therapy with a strategy that was previously ineffective. As a result, maintenance or continuation models of ECT should be implemented.³⁶ Without this, patients will need a complex treatment regimen with medications that have not previously failed, such as lithium in combination with a TCA or an MAOI.³⁷

Psychotherapy. The art of caring for people with difficult-to-treat disorders involves attention to the psychotherapeutic strategies that have been shown for decades to help depressed people. Psychotherapy can help counteract the frustration that can accompany repeated treatment failures.¹² This frustration can impact treatment adherence and the patient-provider relationship (AV 3).³⁸

Psychotherapy can help patients begin to reestablish morale, increase activity, and focus on specific, accomplishable goals.² Patients can also benefit from problem-solving and coping strategies and behaviors. Depression severity and social adjustment can be improved with adjunctive psychotherapy.³⁹

Case Practice Question

Case 1. Ramon, a 53-year-old married chef, has a history of recurrent depression that began at age 24 years. No personal or family history of mania/hypomania exists. About 4 months ago, Ramon presented to his primary care physician with a depressive episode with low energy, increased appetite and weight gain, more time sleeping, and decreased motivation. His metabolic burden has increased as he’s gotten older. Ramon takes a statin for hypercholesterolemia and has mild obesity. He had little response to fluoxetine, up to 40 mg/d over 4 weeks, although this medication had helped him in 2 earlier episodes. He also experienced sexual dysfunction. Ramon was switched to bupropion, which improved his sexual dysfunction over 8 weeks but did not improve his core depressive symptoms. The physician next switched to venlafaxine for 4 weeks, but results have been unsatisfactory. Therefore, Ramon has been referred to you.

Which next-step strategy offers Ramon the highest likelihood for remission?

1. Adding lithium
2. Switching to a TCA
3. Switching to an MAOI
4. Adding an atypical antipsychotic

Discussion of Case Practice Question

Preferred response: c.

Explanation: Although TCAs are typically tried before MAOIs, Ramon’s symptoms are indicative of atypical depression, which is more responsive to MAOIs.⁴⁰ Without mania or hypomania, the addition of lithium is less indicated for Ramon than for some patients. Ramon’s metabolic profile would be at risk for worsening with an added atypical antipsychotic.

Emerging Treatments for MDD

Although targets of existing antidepressant treatments have focused on monoamines, particularly serotonin and norepinephrine, depression most likely stems from multiple pathophysiologies, some of which are not responsive to interventions that target monoaminergic strategies.⁴¹ Thus, the next generation of breakthrough therapies may target different mechanisms.

Alternate hypotheses for the neurobiology of depression are being tested by targeting glutamate receptors or modulating cholinergic and GABAergic transmission, neuronal plasticity, stress/hypothalamic pituitary adrenal (HPA)-axis, the reward system, and neuroinflammation.⁴² The treatments below target these other systems.

Ketamine. Ketamine is a high-affinity NMDA receptor antagonist that also binds to opioid µ and sigma receptors and modulates dopamine transmission. A review⁴³ of ketamine in patients with TRD demonstrated rapid antidepressant effects, confirming the active role of glutamate in the pathophysiology of MDD. Within hours after administration, ketamine was associated with a significant clinical improvement in depressive symptoms and reduced suicidality.⁴³

Ketamine is a dissociative anesthetic with significant psychotomimetic properties.⁴⁴ At normal doses, it enables people to experience surgery while being in a dissociated, twilight state. About one-quarter of the normal anesthetic dose was serendipitously found to have antidepressant effects. Studies with intravenous ketamine show a significant antidepressant and possibly antisuicidal effect in the short term, with response rates over 60% as early as 4.5 hours after a single dose and over 40% after 7 days.⁴⁵ The response can be sustained over several weeks with 2 or 3 doses per week.⁴⁵ Because of recreational abuse potential, ketamine is a controlled substance. The psychotomimetic and dissociative effects of this treatment are not bound to the antidepressant effects, meaning that similar treatments could have a therapeutic effect on depressive symptoms without an accompanying abuse liability.⁴⁶

One meta-analysis⁴⁷ examined 7 trials of the antidepressant effect of ketamine infusions in patients with TRD. Ketamine produced a rapid, yet transient, antidepressant effect, with odds ratios for response and transient remission of symptoms at 24 hours equaling 9.87 (4.37–22.29) and 14.47 (2.67–78.49), respectively.

The rapid response of ketamine is an improvement over the several weeks typically required for current antidepressant treatments. In hospitalized patients with MDD, ketamine was as effective as ECT but faster-acting.⁴⁸ A dose of 0.5 mg/kg infused over 40 minutes 2 or 3 times a week has about a 40% to 60% chance of success of a meaningful reduction of depression symptoms.^43,49 Typically, no response within 2 weeks means another strategy needs to be considered. For patients responding well to ketamine, the strategy is to gradually reduce frequency of infusions (eg, twice a week to once a week to every other week) while trying to find a new antidepressant treatment to replace ketamine.

Several unknowns exist with ketamine. The point at which tolerance develops has not been determined, and concerns exist about neurotoxicity,⁴⁷ which is seen in people who use higher doses of ketamine for recreational purposes.⁴⁴ Another important unknown is whether sustained remission induced by progressively lower doses of ketamine can restore the ability of patients to respond to standard antidepressants.

Esketamine. Esketamine, an enantiomer of ketamine, displays approximately 4 times greater affinity for the glutamate NMDA receptor than ketamine.⁴⁵ Intranasal esketamine theoretically may offer an improved tolerability profile over ketamine and has shown an antidepressant effect comparable with that of ketamine, which has resulted in the FDA granting the drug a Breakthrough Therapy designation.⁴⁵ The most common adverse effects of esketamine in patients with TRD were headache, nausea, and dissociation, but the dissociation did not last longer than 4 hours.⁵⁰

A phase 2 study⁵¹ of intranasal esketamine adjunctive to existing oral antidepressant therapy in TRD showed a rapid antidepressant effect (by day 8) for 3 doses of esketamine (28 mg, 56 mg, or 84 mg given twice weekly) compared with placebo. Response lasted for more than 2 months with a reduced dosing frequency (weekly and then every 2 weeks).

Rapastinel. Rapastinel (formerly GLYX-13) is an allosteric modulator of NMDA receptors with glycine-site partial agonist properties. In addition to its rapid and long-lasting antidepressant properties, rapastinel is a cognitive enhancer.⁵² Rapastinel has better tolerability than ketamine (eg, no psychotomimetic effects), making it a promising alternative to available antidepressants.⁵³ In 2014, it received the Breakthrough Therapy designation for the treatment of MDD from the FDA. It is also being studied as adjunctive therapy in MDD.⁵⁴

Brexanolone. In contrast to the agents targeting NMDA receptors, brexanolone is a positive allosteric modulator of GABA_A. A phase 2 study⁵⁵ investigated brexanolone (formerly SAGE-547 injection), an intravenous formulation of allopregnanolone, in women with severe postpartum depression (n = 21). At 60 hours, mean reduction in HDRS total score from baseline was 21.0 points in the brexanolone group compared with 8.8 points in the placebo group, which was a significant improvement (P = .0075). Results from phase 3 studies⁵⁶ in women with moderate and severe postpartum depression also showed significant reductions in the HDRS scores at 48 hours, and the effects at 60 hours were sustained at 30 days. This rapid response is important for new mothers whose depressive symptoms can hinder bonding with their newborn.⁵⁶ Brexanolone has Breakthrough Therapy status in postpartum depression.⁵⁷

ALKS 5461. ALKS 5461, a combined buprenorphine and samidorphan therapy, is a novel treatment for MDD intended to address endogenous opioid dysregulation in patients with MDD. The novel drug demonstrated efficacy versus placebo as an adjunctive MDD treatment in short-term randomized clinical trials.⁵⁸ Patients with MDD who had had inadequate response to 1 or 2 antidepressant treatments received adjunctive ALKS 5461, and at 4 weeks, significant improvements in depression measures were found.⁵⁹ No opioid withdrawal symptoms were seen at discontinuation. In a long-term phase 3 study,⁶⁰ patients received sublingual ALKS 5461 as adjunctive treatment to antidepressants for up to 52 weeks. Almost half of patients completed the 1-year study (49%); 11% discontinued due to an adverse effect. Mean MADRS-10 scores decreased from baseline in the ALKS 5461 group, and 52.5% of patients achieved remission at 12 months. Nausea, headache, constipation, dizziness, and somnolence were the most commonly reported adverse effects; no withdrawal symptoms were seen at discontinuation.^58,60

Conclusion

Clinicians will encounter many patients who do not respond to initial antidepressant treatment. By focusing first on the assessment of the patient and staging of the depression, clinicians can make logical choices for sequential treatment trials, tracking and learning what seems to be of some help or no help with each step. Encourage patients to focus on small, achievable goals and mobilize their social supports so that they can feel some control and regain morale when they feel defeated. Above all, clinicians must avoid “blaming the victim,” as it is not the patient’s fault when adequate treatment trials fail. If clinicians start to feel that a patient is “a hopeless case,” they should seek consultation from a colleague. New treatments exploring other systems beyond monoamines promise therapeutic benefit for patients with TRD.

Clinical Points

• Use a rating scale, such as PHQ-9 or QIDS-SR, to regularly assess patients’ response to treatment
• For patients with TRD, consider switching, adding, or combining therapies based on mechanism of action and side effects
• Watch for emerging treatments that target other systems and receptors such as NMDA, GABA, and opioid

Abbreviations

CO-MED = Combining medications to enhance depression outcomes, ECT = electroconvulsive therapy, EPS = extrapyramidal symptoms, FDA = US Food and Drug Administration, GABA = γ-aminobutyric acid, HDRS = Hamilton Depression Rating Scale, MADRS = Montgomery-Asberg Depression Rating Scale , MDD = major depressive disorder, MAOI = monoamine oxidase inhibitor, NIMH = National Institute of Mental Health, NMDA = N-methyl-d-aspartate, PHQ-9 = 9-item Patient Health Questionnaire, QIDS-SR = 16-item Quick Inventory of Depressive Symptomatology–Self-Report, SGA = second-generation antipsychotic, SNRI = serotonin–norepinephrine reuptake inhibitor, SSRI = selective serotonin reuptake inhibitor, STAR*D = Sequenced Treatment Alternatives to Relieve Depression, TCA = tricyclic antidepressant, TRD = treatment-resistant depression, VAST-D = VA Augmentation and Switching Treatments for Improving Depression Outcomes.

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