**Question:** An old man is diagnosed with major depressive disorder. His son mentions that he always shows suicidal tendencies. What is the treatment of choice for depression with suicidal tendencies?

**Core Concept:** In patients with major depressive disorder (MDD) and suicidal ideation or behavior, timely and appropriate treatment is crucial to prevent suicide attempts.

**Why the Correct Answer is Right:**

A) Selective serotonin reuptake inhibitors (SSRIs): SSRIs are a class of antidepressants that inhibit the reuptake of serotonin, leading to increased serotonin levels in the brain. This results in improved mood and reduced suicidal ideation.

B) Monoamine oxidase inhibitors (MAOIs): MAOIs are another class of antidepressants that increase serotonin and norepinephrine levels in the brain by inhibiting their degradation. They work by enhancing the neurotransmitter levels, which improves mood and reduces suicidal ideation.

C) Tricyclic antidepressants (TCAs): TCAs are a class of antidepressants that work by increasing the levels of neurotransmitters like serotonin, norepinephrine, and dopamine in the brain, which helps improve mood and reduce suicidal ideation.

D) Lithium: Lithium is primarily used as a mood stabilizer in bipolar disorder but can also be effective in treating severe depressive episodes, particularly when combined with other antidepressants. It is not a first-line treatment for major depressive disorder but can be considered in specific cases.

**Why Each Wrong Option is Incorrect:**

1. Lithium: Although lithium can be effective in treating severe depressive episodes, it is not the first-line treatment for major depressive disorder (MDD). For MDD, SSRIs, MAOIs, and TCAs are considered first-line treatments.
2. Monoamine oxidase inhibitors (MAOIs) are generally reserved for patients with resistant depression or those who have contraindications for SSRIs or TCAs.
3. Tricyclic antidepressants (TCAs) are often used as a first-line treatment for MDD but are not typically recommended as a standalone treatment for severe suicidal ideation.
4. Lithium is not the first-line treatment for MDD, but it can be considered in specific cases.

**Clinical Pearl:** In patients with major depressive disorder and severe suicidal ideation, consider a combination of lithium and an SSRI or MAOI as a treatment option. This combination enhances the effectiveness of both medications when treating suicidal ideation.

**Core Concept:** Selective serotonin reuptake inhibitors (SSRIs) and monoamine oxidase inhibitors (MAOIs) are first-line treatments for major depressive disorder (MDD) with suicidal ideation.

**Why Lithium and Lithium Combination:** Lithium is often used in combination with SSRIs or MAOIs to enhance the effectiveness of both medications when treating suicidal ideation in patients with MDD. This combination has been shown to be more effective than mon