Chapter 3: Biological Basis for Understanding Psychiatric Disorders and Treatments Flashcards
Function and activities of the brain
Maintenance of homeostasis. Regulation of ANS and hormones. Control of biological drives and behavior. Cycle of sleep and wakefulness. Circadian rhythms. Conscious mental activity. Memory. Social skills.
Neuronal action
Neurons can release more than one chemical at the same time. Neuropeptides: long-term changes in cells. Neurotrophic facts: proteins, gases. Effect of steroid hormones.
Core: regulaties internal organs and vital functions.
Hypothalamus: basic drives and link between thought and emotion and function of internal organs.
Brainstem: processing center for sensory information
Function of brainstem
Involved in fine muscle movement. Involved in integration of emotions and thoughts. Involved in decision making. Stimulates hypothalamus to release hormones.
Receptors: D1-5
Decrease: Parkinson’s disease, depression. Increase: Schizophrenia, mania
Dopamine
Level in brain affects mood. Attention and arousal. Stimulates sympathetic brand of the ANS for “fight or flight” in response to stress.
Receptors: alpha-1 and 2; beta-1 and 2.
Decrease: depression.
Increase: mania, anxiety states, schizophrenia
Norepinephrine
Plays a role in sleep regulation, hunger, mood states, and pain perception. Hormonal activity. Plays a role in aggression and sexual behavior. Receptors: 5-HT 1-4
Decrease: depression
Increase: Anxiety states
Serotonin (5-HT)
Involved in alertness. Involved in inflammatory response. Stimulates gastric secretion.
H1 and H2 receptors.
Decrease: sedation, weight gain
Histamine
Plays a role in inhibition; reduces aggression, excitation, and anxiety. May play a role in pain perception. Has anticonvulsant and muscle-relaxing properties. May impair cognition and psychomotor functioning.
Decrease: anxiety disorders, schizophrenia, mania, huntington’s reissues
GABA
Is excitatory. Plays a role in learning and memory.
Decrease: psychosis.
Increase: prolonged increased state can be neurotoxic, neurodegeneration in Alzheimer’s disease, improvement of cognitive performance in behavioral tasks
Glutamate (NMDA, AMPA)
Potentiate, or promote the activity of GABA by binding to a specific receptor on the GABA A receptor complex (binding results in an increased frequency of chloride channel opening causing membrane hyper polarization which inhibits cellular excitation). Nonselective. Can cause sedation at higher therapeutic doses. Treatment of insomnia with a predominantly hypnotic (sleep-inducing) effect: flurazepam (Dalmane), temazepam (Restoril). Lorazepam (Ativan) and alprazolam (Xanax) reduce anxiety without being as soporific (sleep producing) at lower therapeutic doses. Can be used as anticonvulsants.
Benzodiazepines
Addictive. Should only be used a few days at a time. Ataxia is a common side effect secondary to the abundance of GABA receptors in the cerebellum.
-“pams”
Benzodiazepines.
Zolpidem (Ambien), Zalepon (Sonata), Eszopiclone (Lunesta). Inform about the chance of doing things while asleep. Addictive, should only be used short-term. Sedative effects without the anti-anxiety, anticonvulsant, or muscle relaxant effects of BZDs. Potential for amnestic and ataxic s/es. Onset of action faster than most BZDs.
Short-acting sedative-hypnotic sleep agents (Z-hypnotics)
Ramelteon (Rozerem). Approved for tx of insomnia that is not classified as a scheduled substance. S/es: HA, dizziness. Can increase depression.
Melatonin receptor agonists
Silenor. Tx of insomnia characterized by difficulty in maintaining sleep. Histamine-1 blockade. Pts with severe urinary retention or on MAOIs should avoid. not with narrow angle glaucoma, severe sleep apnea.
Doxepin
Reduces anxiety without having strong sedative-hyponotic properties. Does not leave the pt sleepy or sluggish. Not a CNS depressant and thus does not have as great a danger of interaction.
Buspirone (BuSpar)
