Mood disorders

Prevalence

how common the disorder is among the population

Incidence

The # of cases in a specific time

: What is Depression?

Sad or irritable mood, low motivation, sleep/appetite changes, loss of energy, guilt, and suicidal thoughts

What is Mania?

Elevated or irritable mood with decreased need for sleep, racing thoughts, talkativeness, impulsivity, and inflated self-esteem.

What is the key difference between Depression and Mania?

Depression involves low mood and energy; mania involves elevated mood and excessive energy.

What defines Major Depressive Disorder (MDD)?

At least one major depressive episode with no history of mania or hypomania.

How long must a Major Depressive Episode last?

At least 2 weeks.

How many symptoms are required for a Major Depressive Episode?

5 or more symptoms nearly every day.

What are the two core symptoms of MDD?

Depressed mood OR loss of interest/pleasure (anhedonia).

What is Persistent Depressive Disorder (PDD)?

Chronic, milder depressive symptoms lasting at least 2 years (1 year in children).

How long can someone be symptom-free in PDD?

No more than 2 months.

Can someone with PDD have manic or hypomanic episodes?

no

What defines a Manic Episode?

Elevated/irritable mood and increased energy for at least 1 week (or any duration if hospitalized).

What symptoms occur in mania?

: Grandiosity, decreased sleep, talkativeness, racing thoughts, impulsivity, risk-taking.

What is Bipolar I Disorder?

: At least one full manic episode (often alternates with depression).

What defines a Hypomanic Episode?

Elevated/irritable mood lasting at least 4 days, no psychosis, no hospitalization.

What is Bipolar II Disorder?

At least one hypomanic episode and one major depressive episode.

What is Cyclothymic Disorder?

Mild, chronic form of bipolar disorder with hypomanic and mild depressive symptoms lasting ≥2 years.

What is DMDD? (disrupted mood dysregulation disorder) 

Severe recurrent temper outbursts (verbal or physical) and chronic irritability in children ages 6–18.

How often do outbursts occur in DMDD?

At least 3 times per week.

Q: How long must DMDD symptoms persist?

At least 12 months, in at least 2 settings.

Can DMDD be diagnosed with bipolar disorder?

No, DSM prohibits both diagnoses together.

What genetic evidence supports mood disorders?

Higher concordance rates in identical twins; strong genetic component for severe cases.

Which gene is linked to depression?

: 5-HTT gene (affects serotonin transport).

What neurotransmitter is low in depression?

Serotonin.

What neurotransmitter is low in depression and high in mania?

Norepinephrine.

What hormone is elevated in depressed individuals?

Cortisol (stress hormone).

What is Learned Helplessness Theory (Seligman)?

Belief of having no control over outcomes → leads to depression.

What is the Hopelessness Theory?

Negative thinking pattern:

Which brain region shows abnormalities in mood disorders?

Left frontal lobe

What are the four main types of antidepressants?

Tricyclics (TCA), MAOIs, SSRIs, and SNRIs.

What do Tricyclics (TCAs) do?

Block reuptake of norepinephrine; effective but toxic in overdose.

What are MAOIs and why are they risky?

Block enzyme that breaks down serotonin/NE; can cause dangerous reactions with tyramine foods.

What do SSRIs do?

Block serotonin reuptake (e.g., Prozac, Zoloft); fewer side effects, safer.

What do SNRIs do?

Block reuptake of serotonin and norepinephrine (e.g., Effexor, Wellbutrin).

What new medication was approved in 2025 for treatment-resistant depression?

Spravato (esketamine) nasal spray — must be taken in a clinic and monitored.

What is the first-line medication for bipolar disorder?

Lithium — effective mood stabilizer, prevents suicide.