Major depressive disorder

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Major depressive disorder

Psychological disorders

Bipolar and related disorders

Bipolar disorder

Feeding and eating disorders

Anorexia nervosa

Bulimia nervosa

Medication-induced movement disorders and other adverse effects of medication

Neuroleptic malignant syndrome

Serotonin syndrome

Somatic symptom and related disorders

Factitious disorder

Somatic symptom disorder

Trauma and stressor-related disorders; Abuse

Physical and sexual abuse

Post-traumatic stress disorder


Major depressive disorder


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High Yield Notes

5 pages


Major depressive disorder

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External References

First Aid








Cognitive behavioral therapy (CBT) p. 580

postpartum depression p. 585

Postpartum depression p. 585

SSRIs (selective serotonin reuptake inhibitors) p. 599

postpartum depression p. 585


Content Reviewers

Clinical depression, which is sometimes called major depressive disorder or unipolar depression, is a serious mental disorder characterized by by persistent sadness and a loss of interest in the activities of daily life, like working, studying, participating in hobbies, eating, and sleeping.

Clinical depression has a lifetime incidence of up to 20% in women and 12% in men, making it one of the most common reasons people seek out mental health services.

In addition to being relatively common, clinical depression is very serious because it essentially leads to an overall feeling that life isn’t enjoyable.

We don’t exactly know what specifically causes clinical depression, but it’s probably the result of a combination of genetic factors, biological factors, environmental factors, and psychological factors.

It’s been shown that people with family members who have depression are three times more likely to have it themselves, especially if they’re closely related.

Medications that address the biological factors of depression focus specifically on neurotransmitters.

Neurotransmitters are signaling molecules in the brain that are released by one neuron and received by the receptors of another neuron.

Through this process, a message is transmitted from one neuron to the next.

The body’s ability to regulate how many of these neurotransmitters are sent between neurons at any given time is thought to play an important role in the development of depression’s symptoms.

That’s because neurotransmitters are likely involved in regulating a lot of brain functions, including mood, attention, sleep, appetite, and cognition.

The three main neurotransmitters that treatment for depression focuses on are serotonin, norepinephrine, and dopamine.

That’s because medications that increase the amount of these neurotransmitters in the synaptic cleft — this space between the neurons — are shown to be effective antidepressants.


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