Mood disorders: Pathology review

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Mood disorders: Pathology review

Psychological disorders

Psychological disorders

Psychological disorders


Mood disorders: Pathology review

USMLE® Step 1 questions

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USMLE® Step 1 style questions USMLE

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A 28-year-old woman comes to her physician complaining of low energy and an irritable mood for several weeks. She was recently accepted into a master's program and was ecstatic to begin in the fall semester. Once classes started, she began experiencing feelings of “worthlessness.” Her history is significant for self-described “mood swings,” which consist of several-week periods of productivity and improved mood, followed by several-week periods of fatigue, guilt, and depressed mood. She takes no medications. She drinks 2-3 glasses of wine on the weekends. Physical examination is within normal limits.  Mental status examination reveals a visibly tired woman who often needs questions repeated due to inattentiveness. Which of the following is the most likely diagnosis?  


54 year old Liam presents to the clinic because of a persistent feeling of sadness, ever since he got divorced and his former wife moved out with their son, five months ago.

Liam mentions that he doesn’t enjoy anything anymore, not even listening to his favorite songs.

However, he does briefly cheer up every time his son visits him.

Upon further questioning, Liam admits to gaining a lot of weight recently, and feels like he can’t stop eating.

When you ask Liam about his sleep habits, he tells you that he often sleeps more than 13 hours a night, but still feels tired when waking up.

Next to him, 25 year old Elfie is brought to the clinic by her father, who is worried that Elfie has not slept much for the past 5 days, but still seems overly energetic.

Her father is also furious because two days ago Elfie maxed out her credit cards shopping for clothes.

Elfie interrupts him to say that nobody understands her, because she’s more intelligent than everyone on this planet!

Then, Elfie starts pacing around the room as she continues to speak rapidly and jumps from one topic to another.

She denies experiencing any psychotic symptoms, like hearing or seeing things that others don't.

Finally, Elfie also mentions that she hasn't stopped going to work or interacting with her colleagues these past five days.

Okay, based on the initial presentation, both Liam and Elfie seem to have some form of mood disorder.

Many of us can have days when we feel sad or overly happy.

But with mood disorders, these emotional variations can become impossible to control, sometimes even to the point where they interfere with day-to-day activities like working, studying, eating, and sleeping.

Now, the main risk factors seem to include having a family history or experiencing a personal trauma.

However, the underlying cause is poorly understood; for your exams, what you need to remember is that there’s usually an imbalance of the neurotransmitters serotonin, norepinephrine, and dopamine, which normally help regulate mood, reward-motivated behavior, appetite, and sleep.

Mood disorders can be seen as a spectrum of emotional states that range from depression or extreme sadness to mania or excessive excitement.

So at one end of the spectrum, we have depressive disorders, which are characterized by depressive episodes that consist of nine key symptoms.

First, a person feels depressed or sad, hopeless, and may lack a sense of purpose most of the day, every day.


Mood stabilizers are a class of medications used to treat mood disorders, such as bipolar disorder and persistent depressive disorder. There are several different types of mood stabilizers, including lithium, valproate, and carbamazepine.

Nursing considerations for patients taking mood stabilizers include monitoring for side effects, dosing, educating patients about medication, and adherence. It is also crucial that nurses know any potential drug interactions and carefully monitor patients for any changes in their mood or behavior.


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  5. "Depressive disorders in Europe: prevalence figures from the ODIN study" British Journal of Psychiatry (2001)
  6. "Diagnostic and Statistical Manual of Mental Disorders" NA (1980)
  7. "Initial Severity and Antidepressant Benefits: A Meta-Analysis of Data Submitted to the Food and Drug Administration" PLoS Medicine (2008)
  8. "Major Depressive Disorder" Oxford University Press, USA (2015)

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