Psychopharmacology Flashcards
Types of Psychoactive Drugs
Depressants
Stimulants
Hallucinogens
- All do their work at the brain’s synapses
- Stimulate, inhibit, or mimic activity of the brain’s own
chemical messengers, the neurotransmitters
Psychoactive Drug
A chemical substance that alters perceptions and/or mood
Drug Effects on the DA System
Many antipsychotic drugs block DA receptors
- Typical neuroleptics block DA receptors
- Atypical neuroleptics block DA and other classes of
receptors
Methylphenidate: Inactivates transporter molecule, preventing reuptake of DA
- Results in more DA in the synapse
- Increases attention
Caffeine
Stimulant, mostly because it blocks adenosine receptors (and adenosine normally reduces DA & Glu activity)
Amphetamine
DA & NE agonist:
1. Reverses action of dopamine transporter (DAT)
2. Reverses vesicular monoamine transporter (VMAT)
Blocks the metabolism of catecholamines as well as serotonin in the brain and from sympathetic nerves.
Drug Effects on the NE System
Methamphetamine: reverses the NE & DA transporter
molecules
- Floods the synapse with NE & DA
- Causes euphoria, increase arousal & energy,
perseverative behaviors, loss of appetite, irritability,
and agitation
- Highly addictive
- Repeated use results in overall lack of hygiene &
nutrition, meth mouth, erectile dysfunction, acne &
skin lesions, trichotillomania, psychosis, etc.
Drug Effects on the GABA System
Alcohol, benzodiazepines, and barbiturates…
- Indirect GABA receptor agonists
Alcohol and gamma-hydroxybutyric acid (GHB)
- Direct GABA receptor agonists
All GABA agonists are CNS depressants
- Produce sleep, anxiety relief, muscle relaxation, and
seizure alleviation
- High abuse potential and risk of overdose
Opiates & Their Effects
Lysergic Acid Diethylamide 25 (LSD) - stimulates 5-HT
receptors in the forebrain and visual cortex
- Powerful agonist, causes hallucinations
MDMA (ecstasy, molly) - reverses the 5-HT, DA, and NE
transporter molecules
- Floods the synapse with 5-HT, DA, and NE
- Causes euphoria, decreases anxiety, feelings of well-
being, empathy, & intimacy
- repeated use may cause damage to the 5-HT system &
cognitive impairment
- Encourages prosocial bonding, and used as final aid for
people with PTSD sometimes
Drug Effects on the Endocannabinoid System
Delta 9 (THC) - stimulates the CB receptors
- Produces analgesia and sedation, stimulates appetite,
reduces nausea & vomiting, relieves asthma attacks,
decreases symptoms of glaucoma, certain motor
disorders, wasting syndrome, depression, deceases
anxiety, etc…
- Prevents excitotoxicity
- Interferes with concentration, memory, visual,
auditory, & time perception
- Effects depend on the strain of the plant, mode of
ingestion, and psychological expectations
Endocannabinoids
Anandamide, 2-AG, Oleamide-lipid based molecules
Lipid-based molecules, produced on demand at the postsynaptic membrane
- Not stored in vesicles
- Transmit messages between cells via retrograde transport
- Act on CB1 & CB2 cannabinoid receptors
Work throughout the CNS & PNS to modulate neural activity
Nicotine Acts as a Stimulant
- Increases heart rate, blood pressure, digestive action,
and alertness- Acts as an agonist on nicotinic ACh receptors in the
cortex, enhancing some cognitive functions, and the
ventral tegmental area, activating reward/addiction
pathways
- Acts as an agonist on nicotinic ACh receptors in the
Four Major Models of Drug Abuse
Moral Model: abuser lacks moral character or self-control
Disease Model: abuser requires medical treatment
Physical Dependence Model: abusers use drugs to avoid
withdrawal symptoms like dysphoria
Positive Reward Model: drug use is behavior controlled by
positive rewards
Dopamine in the Nucleus Accumbens
- Many axons that terminate in the nucleus accumbens (NaCC) originate in the ventral tegmental area (VTA) and are involved in the reward pathway
- The addictive power of drugs may come from stimulating this pathway
- Another pathway may involve the insula, a brain region within the frontal cortex.
