AIIMS Nagpur NO- 2020: In depression, there is deficiency of:

AIIMS Nagpur NO- 2020

Mental Health Nursing

Easy

Appeared in: AIIMS Nagpur NO- 2020

Explanation

The question asks about the primary neurotransmitter deficiency in depression.
According to the monoamine hypothesis, depression is linked to a deficiency of monoamine neurotransmitters, particularly serotonin (5-hydroxytryptamine or 5-HT).
While norepinephrine and dopamine are also implicated, serotonin is the most prominently associated neurotransmitter.
The effectiveness of Selective Serotonin Reuptake Inhibitors (SSRIs), which specifically increase serotonin levels in the synaptic cleft, provides strong evidence for this link.

Option A: While low dopamine levels can contribute to specific symptoms of depression, such as anhedonia (lack of pleasure) and low motivation, it is not considered the primary or most common neurotransmitter deficiency responsible for the overall syndrome of depression.
Option B: Acetylcholine is primarily involved in cognitive functions like memory and learning, as well as muscle control. It is not directly implicated in the core mood symptoms of depression according to the monoamine hypothesis.
Option C: GABA is the main inhibitory neurotransmitter in the brain. While it plays a role in mood regulation, low levels of GABA are more strongly and directly associated with anxiety disorders, seizures, and insomnia rather than depression.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Neurochemical Basis of Depression (Monoamine Hypothesis) as background academic context rather than a clinical decision trigger.
Understanding that depression is linked to a chemical imbalance helps nurses educate patients and families, reducing stigma and improving medication adherence.
Nurses must monitor patients on antidepressants like SSRIs for therapeutic effects (mood improvement) and potential side effects, including the risk of Serotonin Syndrome, a life-threatening condition caused by excessive serotonin activity.
What if a patient does not respond to an SSRI? This is known as treatment-resistant depression. The next step often involves switching to or adding a medication that targets other neurotransmitters, such as a Serotonin-Norepinephrine Reuptake Inhibitor (SNRI) or a drug that affects dopamine, reinforcing the multi-neurotransmitter nature of depression.

How to Approach the Question

First, identify the core concept of the question, which is the neurochemical basis of depression.
Recall the main biological theory related to depression, which is the monoamine hypothesis.
List the key neurotransmitters involved in the monoamine hypothesis: Serotonin (5-HT), Norepinephrine, and Dopamine.
Evaluate the given options against this theory. Recognize that while all three monoamines are involved, serotonin (5-HT) is considered the primary neurotransmitter implicated in depression and is the target of the most common first-line antidepressants (SSRIs).
Eliminate the other options by recalling their primary functions: Dopamine (reward/motivation), Acetylcholine (cognition/muscle), and GABA (inhibition/anxiety).

Concept Tested & Keywords

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E6 Kaplan Sadock's Synopsis of Psychiatry-2022 (pp 1-3768 of 3768) pp. 1268-1270, 1269-1271