Psychology & Sociology
Depressive disorders are characterized by persistent and severe sadness, which often affects one's daily functioning. A host of other symptoms are associated with these disorders, sometimes referred to by the acronym SIGECAPS, including changes in sleep, loss of interest in activities, feeling guilty, decreased energy levels, difficulty concentrating, changes in appetite, psychomotor disturbances, and suicidal thoughts. Six specific depressive disorders include major depressive disorder, persistent depressive disorder (formerly dysthymia), disruptive mood dysregulation disorder (diagnosed in children), peripartum depression (during or after pregnancy), premenstrual dysphoric disorder (coinciding with menstruation), and seasonal affective disorder (coinciding with changes in season).
The monoamine theory of depression proposes that depressive disorders are caused by a deficiency of monoamines (neurotransmitters with a single amine group, such as dopamine, serotonin, and norepinephrine). However, genetics and an individual's environment also play a crucial role in depression and may influence monoamine levels.
Lesson Outline
<ul> <li>Introduction to depressive disorders</li> <ul> <li>Persistent and severe sadness</li> <li>Affects daily functioning</li> <li>Symptoms: changes in sleep, loss of interest, feeling guilty, decreased energy, difficulty concentrating, changes in appetite, psychomotor disturbances, suicidal thoughts (SIGECAPS)</li> <li>Variations in expression and combinations of symptoms</li> </ul> <li>Major depressive disorder</li> <ul> <li>At least one depressive episode</li> <li>Five or more SIGECAPS symptoms for at least two weeks</li> </ul> <li>Persistent depressive disorder (formerly known as dysthymia)</li> <ul> <li>Similar to major depressive disorder, but milder and longer lasting</li> <li>Sadness and two or more SIGECAPS symptoms on most days for at least two years</li> </ul> <li>Disruptive mood dysregulation disorder (diagnosed in children)</li> <ul> <li>Severe irritability or anger on most days and in multiple settings</li> <li>Exceeds what's expected based on the child's age and circumstances</li> </ul> <li>Peripartum depression (formerly postpartum depression)</li> <ul> <li>Prolonged and debilitating depressive symptoms during pregnancy or the first month after giving birth</li> </ul> <li>Premenstrual dysphoric disorder (diagnosed in people who menstruate)</li> <ul> <li>Depressive symptoms the week before their period starts, improving within a week of the period ending</li> </ul> <li>Seasonal affective disorder</li> <ul> <li>Depressive episodes that start and stop around the same time each year, often in winter</li> <li>Disruption of neurotransmitters serotonin and melatonin</li> </ul> <li>Biological basis of depressive disorders</li> <ul> <li>Monoamine theory: deficiency of monoamines (neurotransmitters with a single amine group)</li> <li>Three key monoamines: dopamine, serotonin, norepinephrine</li> <li>Role of genetics and environment in depression</li> </ul> </ul>
Don't stop here!
Get access to 51 more Psychology & Sociology lessons & 8 more full MCAT courses with one subscription!
FAQs
Major depressive disorder (MDD) is characterized by one or more episodes of severe depression lasting at least two weeks. Persistent depressive disorder (PDD), also known as dysthymia, is a milder but more chronic form of depression, lasting for at least two years. Individuals with MDD often experience more severe symptoms that can significantly impair their daily functioning, while those with PDD may experience fewer or less intense symptoms but often suffer from a more persistent, long-lasting depressive state.
Peripartum depression and premenstrual dysphoric disorder (PMDD) are both classified as depressive disorders because they involve the onset of depression in relation to specific periods in a woman's reproductive cycle. Peripartum depression occurs during pregnancy or within four weeks after childbirth and can negatively affect both the mother and infant. PMDD is a severe form of premenstrual syndrome (PMS) that occurs one to two weeks before menstruation and causes intense emotional and physical symptoms, including depression, irritability, and mood swings.
Seasonal affective disorder (SAD) is a type of depressive disorder characterized by recurrent episodes of depression that typically occur during certain times of the year, most commonly in the fall and winter months. The cause of SAD is not fully understood, but it is believed to be related to the reduced exposure to sunlight during these times, which can disrupt the body's internal clock and lead to a decrease in serotonin and melatonin levels, both of which play a role in regulating mood and sleep patterns.
The monoamine theory of depression proposes that depressive disorders are caused by an imbalance in the levels of certain neurotransmitters in the brain, specifically serotonin, dopamine, and norepinephrine. These neurotransmitters are known as monoamines and are responsible for regulating mood, motivation, and various cognitive functions. According to this theory, a deficiency in one or more of these neurotransmitters can lead to the development of depressive symptoms. This theory is supported by the observation that many antidepressant medications work by increasing the availability of monoamines in the brain.
Serotonin, dopamine, and norepinephrine are neurotransmitters that play crucial roles in regulating mood, motivation, and cognitive functions. They are the primary neurotransmitters involved in the monoamine theory of depression. Serotonin is involved in regulating mood, social behavior, appetite, and sleep. Dopamine is responsible for regulating motivation, reward, and the experience of pleasure. Norepinephrine is involved in the regulation of attention, alertness, and the stress response. Imbalances in the levels of these neurotransmitters can contribute to the development of depressive disorders, and thus they are often targeted by antidepressant medications.
