A nurse is discussing the theories that explain the biological basis of Major Depressive Disorder (MDD) with a group of nursing students. Which theory suggests that depression is caused by an imbalance of neurotransmitters in the brain that regulate mood, motivation, reward, cognition, and stress response?

Choice A rationale:

Increased interest in activities is not consistent with the clinical presentation of MDD. In fact, a hallmark symptom of MDD is anhedonia, which involves a reduced interest or pleasure in most activities.

Choice B rationale:

Weight gain is not typically associated with MDD. In contrast, significant changes in appetite and weight loss are more common symptoms, often accompanied by feelings of worthlessness or guilt related to body image.

Choice C rationale:

Excessive guilt and self-blame are common cognitive and emotional symptoms of MDD. Individuals with MDD tend to have a negative self-perception and may blame themselves for their difficulties.

Choice D rationale:

Insomnia, or difficulty falling asleep or staying asleep, is a common sleep disturbance associated with MDD. Sleep problems can exacerbate the symptoms of depression and impact overall well-being.

Choice E rationale:

Elevated mood and increased energy are actually more indicative of conditions like bipolar disorder or manic episodes, where there are distinct periods of abnormally elevated mood, known as mania or hypomania.

Choice A rationale:

Symptoms of major depressive disorder (MDD) are characterized by causing significant distress, not mild distress. The distress associated with MDD is usually severe and impairs daily functioning.

Choice B rationale:

While insomnia is a common symptom of major depressive disorder (MDD), it is not necessary for the diagnosis. Other symptoms, such as changes in appetite, psychomotor agitation or retardation, fatigue, and diminished interest or pleasure, can also contribute to the diagnosis.

Choice C rationale:

The correct answer. Symptoms of major depressive disorder (MDD) must not be due to a medical condition. It's crucial to rule out medical conditions that can mimic depressive symptoms, such as hypothyroidism or certain neurological disorders.

Choice D rationale:

The presence of a manic or hypomanic episode would indicate a diagnosis of bipolar disorder, not major depressive disorder (MDD). Bipolar disorder involves distinct periods of both elevated mood and depressive episodes.

Choice E rationale:

The correct answer. To meet the diagnostic criteria for major depressive disorder (MDD) according to DSM-5, an individual must experience five or more symptoms of depression during a continuous two-week period. These symptoms must include either depressed mood or loss of interest/pleasure. The scenario did not specify all the symptoms, but the persistent feelings of sadness, guilt, worthlessness, weight loss, and insomnia described align with the criteria.