Depression and Bipolar

Depression #

Depression as a symptom:

depressed mood (sad, empty, hopeless), irritable
loss of interest/pleasure (anhedonia)

Depression as a disorder (major depressive disorder): 5 or more of the below symptoms in a 2 week period

weight loss/gain
sleep problems
psychomotor agitation/retardation
fatigue
feeling worthless or excessive guilt (such that it affects others negatively)
decreased concentration
thoughts of death and suicide

Only 50% of adolescents with depression are diagnosed before adulthood.

adults expect teens to be moody
depression might express more as irritability rather than sadness in youth
cultural norms around depression: may be taboo in cultures

Etiology #

Depression is heritable and runs in the family (genetic risk factor)
Family history increases risk of maternal depression, which influences the child’s prenatal environment. (risk factor)
This impacts infants’ brain structure and function. (endophenotype)
Postnatal environment is influenced both by infants’ behavior, and parental depression affecting parenting style. (risk factor)
Gene-environment interaction can create personality patterns that make children more vulnerable. (mediator)
Stressful life events are more likely to trigger depressive symptoms due to prior risk (moderator)

Biological systems #

Reward system (dopamine) and reward mediation model
- stress -> reward dysfunction -> depression
- example: soldiers deployed in stressful high conflict areas showed reduction in reward response, and higher depressive systems
Stress system (LHPA) and stress generation model
- reward dysfunction -> stress -> depression
- example: if reward is not experienced for social interactions, youth will withdraw from relationships -> interpersonal stress contributes to depression
Cognitive control/executive function system (prefrontal cortex) and diathesis stress model
- stressors moderate reward dysfunction -> depression
- example: a twin with more stressful life events is more likely to develop depression despite having the same genetic risk

Treatment #

Cognitive Behavioral Therapy: Emotions (instant) lead to thoughts (delayed), which lead to behaviors (response to stressful situation).

Negative emotions often are the root cause of depressive thoughts (“I should have…”, cognitive distortions) However, targeting emotions directly is ineffective (“don’t be sad/depressed”…).

Instead, CBT focuses on putting behaviors first (e.g. writing down the first thing you will do when you wake up, and doing it even if you don’t feel like it). This will then affect emotions.

Antidepressants: using drugs to target neurotransmitters

SSRIs: selective serotonin reuptake inhibitors (prozac, lexapro, zoloft, celexa, luvox, paxil)
Tricyclic antidepressants (norpramin, tofranil, pamelor): only prescribed if SSRIs don’t work due to more side effects
Monoamine (MAO) oxidase inhibitors: marplan, nardil, emsam, parnate

Research shows that a combination of CBT and antidepressants is most effective; just antidepressants alone is ineffective due to:

not targeting thoughts/behaviors
us not actually knowing how they really work
genetic variability between individuals
cuts off extreme emotions of all kinds, including positive emotions

Bipolar Disorder #

Bipolar disorder is depressive disorder with episodes of mania.

Bipolar I: mania, II: hypomania

Bipolar has extremely high heritability.

Symptoms of mania #

elevated mood
increased motor activity and energy
increased sexual interest
decreased need for sleep
increased irritability
increased rate of uninterruptible, continuous speech
language-thought disorder: frequently changes topics, difficult to follow, often incoherent
grandiose or paranoid ideas, delusions, hallucinations
disruptive-aggressive disorder: threatening, demanding, destructive
often denies illness

Mania vs Hypomania:

Mania is more severe (1 week vs 4 days, with higher functional impairment)
Individuals experiencing mania are often dysfunctional and need to be hospitalized

ben's notes