Depression treatment and neurobiology Describe the proposed neurobiology of depression from the perspective of effective treatment with a selective serotonin reuptake inhibitor (SSRI). That is if an SSRI “works” to alleviate depressive symptoms then what would account for the pathophysiologic mechanisms at work in depression? Describe the roles of atypical antipsychotics as mood stabilizers. Include proposed mechanism(s) of action and evidence for use.

Purpose:

The purpose of required threaded discussions is an interactive dialogue among instructors and students to assist the student in organizing, integrating, applying, and critically appraising one’s knowledge regarding the nursing profession and selected area of practice. Scholarly information obtained from current sources as well as professional communication is required. The articles should have been published within the past 5 years and be peer-reviewed. In some cases, you will need to pull in content from the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

Application of information to advanced practice nursing experiences promotes the analysis and use of principles, knowledge, and information learned and related to real-life clinical situations. Interactive dialogue among instructors and peers fosters the development of a learning community as ideas, perspectives, and knowledge are shared. 

Depression is linked to an imbalance in brain chemicals, particularly serotonin (5-HT), norepinephrine (NE), and dopamine (DA). This is known as the monoamine hypothesis, which suggests that low levels of these neurotransmitters contribute to feelings of sadness, fatigue, and lack of motivation.

However, newer research points to the neuroplasticity hypothesis, which focuses on changes in brain structure and function. Stress and depression can lead to reduced connections between brain cells, especially in areas like the hippocampus and prefrontal cortex, which are important for mood regulation.

How Do SSRIs Help?

Selective serotonin reuptake inhibitors (SSRIs) are a common treatment for depression. They work by blocking the reabsorption (reuptake) of serotonin, making more of it available in the brain. This improves communication between nerve cells and helps regulate mood.

Although SSRIs increase serotonin levels quickly, it takes a few weeks for full effects to be seen. This is because SSRIs also trigger long-term changes, such as:

• Boosting brain cell growth in the hippocampus through a protein called brain-derived neurotrophic factor (BDNF).
• Regulating the body’s stress response by controlling cortisol (the stress hormone).

Atypical Antipsychotics as Mood Stabilizers

Sometimes, SSRIs alone are not enough. Atypical antipsychotics (like aripiprazole, quetiapine, and olanzapine) are added to treatment, especially for treatment-resistant depression (TRD) or bipolar disorder.

These medications work differently from SSRIs:

• They block serotonin (5-HT2A) and dopamine (D2) receptors, which helps balance mood.
• Some, like aripiprazole, act as dopamine stabilizers, preventing extreme highs or lows.
• They also reduce inflammation in the brain and promote brain cell growth, helping restore normal brain function.