Major Depressive Disorder (MDD) Lecture Notes

Vocabulary flashcards covering the prevalence, determinants, pathophysiology, and treatment methods for Major Depressive Disorder (MDD) based on the lecture transcript.

Major Depressive Disorder (MDD)

A debilitating disease characterized by at least one discrete depressive episode lasting at least $2$ weeks and involving clear-cut changes in mood, interests, and pleasure, as well as changes in cognition and vegetative symptoms.

Prevalence of Depressive Symptoms

$1$ in $6$ Americans report symptoms of depression.

Total Economic Burden of MDD

$380\,\text{billion}$.

MDD Disability Standing

MDD is listed $2\text{nd}$ on the disability list.

MDD Suicide Risk

Patients with MDD are almost $20$-fold more likely to die by suicide than the general population.

Global Suicide Factor

$50\%$ of the $800,000$ suicides per year worldwide occur within a depressive episode.

Environmental Determinants

Factors such as absence of a partner (divorce or widowhood), recent negative life events, illness, loss of relatives, financial problems, or unemployment.

Childhood Adversities

Social determinants of MDD often linked to higher symptom severity, a poorer disease course, and more treatment non-response.

Mean Episode Duration

In population-based samples, the average duration of an MDD episode varies between $13$ and $30$ weeks.

Recurrence Rate

$80\%$ of patients in remittance experience at least one recurrence in their lifetime.

MDD Heritability

The heritability for MDD has been quantified as approximately $35\%$, often involving many genes with small effects.

First-degree Relatives Risk

Individuals with first-degree relatives diagnosed with MDD show a threefold increased risk of the disorder.

HPA Axis Activity in Abuse Survivors

Adults who were sexually or physically abused in childhood show a markedly enhanced activity of the HPA axis when exposed to psychosocial stressors.

Corticotropin-releasing hormone (CRH)

Neural circuits containing this hormone show persistent increases in activity due to early-life stress.

Glucocorticoid Resistance

A condition in MDD where glucocorticoid receptor function is reduced, leading to HPA axis hyperactivity and increased inflammation.

Brain Volume Reductions

Structural MRI shows smaller volumes of the basal ganglia, thalamus, hippocampus, and orbitofrontal cortex in patients with MDD.

Cognitive-Behavioral Therapy (CBT)

A therapy that teaches patients to identify negative, distorted thinking patterns and replace them with more accurate, positive ones.

Behavioral Activation Therapy

Focuses on increasing positive activities that provide pleasure or mastery and identifying/confronting avoidance processes.

Psychodynamic Therapy

Helps patients gain insight into how emotions, thoughts, and earlier life experiences created patterns contributing to current problems.

Problem-solving Therapy

Teaches a structured set of skills to generate creative methods to address problems and overcome barriers to goals.

Interpersonal Therapy

Focuses on resolving problems in relationships and social roles, such as conflicts, transitions, or diminished relationships.

Mindfulness-based Therapy

A meditative practice involving paying attention to thoughts and feelings in a non-judgemental manner, accepting things as they are.

Tricyclic Antidepressants (TCAs)

Classic treatments including drugs such as Amitriptyline, Imipramine, and Desipramine.

Selective Serotonin Reuptake Inhibitors (SSRIs)

Classic treatments for MDD that include Sertraline and Fluoxetine.

Selective Norepinephrine Reuptake Inhibitors (SNRIs)

Classic treatments for MDD that include Venlafaxine and Duloxetine.

Monoamine Oxidase Inhibitors (MAOis)

Classic treatments for MDD that include Phenelzine.

Vegetative Symptoms

Physical symptoms such as changes in appetite or sleep that characterize a major depressive episode.

Outpatient Remission Rates

Only $25\%$ of patients in outpatient care remit within $6$ months, and more than $50\%$ still have MDD after $2$ years.

Polygenic

The risk of MDD involves many genes, each exerting small effects, rather than a single gene.

Inflammatory System in MDD

Under physiological inhibitory control by cortisol, this system shows increased activation in MDD due to reduced glucocorticoid receptor function.