Bio Psych Exam 2 Part 2

Drugs for Psych Disorders

Brain pathology of Major Depressive Disorder

• depletion of DA, 5-HT, NE

• But during mania excess amount of monoamines

Dopamine Pathways (3 of them)

Mesolimbic pathway: Involved in reward and motivation, connecting the VTA to the nucleus accumbens and prefrontal cortex.

Mesocortical pathway: Involved in cognitive functions like attention and decision-making, connecting the VTA to the prefrontal cortex.

Nigrostriatal pathway: Involved in motor control, connecting the substantia nigra to the striatum

Serotonin Pathways

Starts in brainstem, projects to amygdala, hippocampus, prefrontal cortex

Types of Drugs to Treat Depression

• MAOIs

• Tricyclics

• SSRI

• SNRI

• Ketamine (NMDA antagonist)

Go to slides and go over all of these and know them

mechanisms of anxiety (GAD)

• Increase of norepinephrine

• Tryptophan, 5-HT, and 5-HIAA down (decrease in serotonin)

• GABA receptor dysfunction

Barbituates

• Cause changes in the GABAa receptor that leads to the opening of Cl- ion channel, causing increased GABA response —> calming effect

• Act on reticular formation area (consciousness, sleep, eating) —> overdose risk (as well as respiratory depression)

• Used to be used to treat anxiety

• Examples: Brevital, Nembutal

Benzodiazepines

• Enhance GABA activity by binding to BZD sites (allosteric site binding causes enhanced GABA binding)

• Used to treat GAD, panic isorder, social anxiety disorder

MAOIs

•first discovered in the 1950s

•inhibit the action of monoamine oxidase that breaks down monoamines (DA, 5-HT, NE)

•Examples of MAOIs include: Nardil (phenelzine)

•severe reactions with food high in tyramine (causing high blood pressure) and other drugs

•Other side effects: nausea, dizziness, restlessness, weight gain, reduced libido

•Also effective for social phobia, bulimia, PTSD, borderline personality disorder, and bipolar depression

Classic Tricyclics

•Also  discovered in the 1950s. Elavil (amitriptyline)

•named after their chemical structure composed of three interconnected rings of atoms.

•Block NE and 5-HT reuptakes but also anti- HAM

•Anticholinergic side effects: constipation, dry mouth, blurry vision, drowsiness, irregular heartbeats

•Antihistamine: fatigue, sedation,

•Antiadrenergic: hypotension, arrythmia

•Low therapeutic index; not for suicidal patients

•Effective for depression, OCD

SSRI

•developed during the 1970

•prevent the reabsorption (reuptake) of 5-HT

•Examples include:

•Prozac (fluoxetine)

•Zoloft (sertraline)

•fewer side effects than older antidepressants but are still known to nausea,  insomnia, sexual dysfunction, serotonin syndrome (insomnia, agitation, diarrhea, sweat, chills, tremors, muscle spasms)

•withdrawal

•Effective for depression, OCD, GAD, eating disorders,

SNRIs

•FDA-approved since 1993. Cymbalta (duloxetine)

•

•Block 5-HT and NE inhibitors

•Increasing NE and 5-HT can be useful for those with psychomotor retardations (the slowing of physical movement and thought)

•Side effects less severe: nausea, drowsiness, fatigue, constipation

•Effective for depression, GAD, PTSD, social anxiety disorder, panic disorder, fibromyalgia.

Ketamine (NMDA antagonist)

•dissociative anesthetic

(detached from the pain; feeling of leaving one’s body)

•Altered body perception (made of rubber; plastic; wood; bizarre body shape or size)

•Sensation of light coming through the body and colorful vision

•sometimes auditory hallucinations

•sudden insight

Why does the young brain have a higher risk of addiction and have larger affects of drug use?

• More neuroplastic

• Young brain is still developing: Limbic system (learning), frontal cortex (decision making)