A 23-year-old woman presents to her psychiatrist concerned about her mood. She has felt tired and unwilling to engage in any activities lately. She states that her limbs feel heavy all the time and that completing any activity takes tremendous effort. She no longer finds any happiness in activities that she previously enjoyed. She struggles to sleep and at times can't sleep for several days. The patient is started on appropriate first-line therapy and sent home. She returns 1 week later stating that her symptoms have not improved. She is requesting help as her performance at work and school is suffering. Her temperature is 99.5°F (37.5°C), blood pressure is 115/72 mmHg, pulse is 60/min, respirations are 13/min, and oxygen saturation is 98% on room air. Which of the following is the most appropriate next step in management?
Add lithium to treatment regimen
Change treatment to duloxetine
Change treatment to lithium
Continue current therapy
Continue current therapy
This patient is presenting with depression and should be treated with a selective serotonin reuptake inhibitor (SSRI) for at least 4 weeks. Patients who have tried the therapy for a shorter duration of time may not yet have experienced the benefit of the medication.

Depression presents with SIGE CAPS (Sleeplessness, Interest loss, Guilt, Energy decreased, Concentration abnormalities, Appetite changes, Psychomotor retardation, and Suicidal ideation). The most appropriate initial step in management is to treat the patient with an SSRI for at least 4 weeks since SSRI's take several weeks to reach their potential. If the treatment has failed after 4 weeks of use, altering the patient's medications could be appropriate. Treatment and side effects should be monitored by a physician.

Kato et al. review the evidence regarding the treatment of depression with SSRI medications. They discuss how medications should be used for at least 4 weeks to determine treatment response. They recommend not allowing patients to switch between drug classes too early.

Incorrect Answers:
Answer A: Adding lithium to the treatment regimen could be an appropriate treatment if this patient had failed to respond to therapy after 4 weeks of using the drug. Lithium is an augmenting agent that could potentiate the effect of an SSRI.

Answer B: Changing the treatment to duloxetine would be inappropriate as this patient has not taken the first-line SSRI for at least 4 weeks. Patients should try a full treatment course in order to determine if they may derive some benefit.

Answer C: Changing the treatment to lithium would be appropriate if this patient's diagnosis was bipolar disorder, which would present with episodes of depression and mania. Altered sleep alone does not indicate mania.

Answer E: Electroconvulsive therapy is the most effective treatment for depression; however, it is typically a last-line treatment. This therapy can be useful in refractory cases.

Bullet Summary:
SSRI medications are the most appropriate first-line agent for depression and should be tried for at least 4 weeks before changing therapy.