neuropsychology and pharmacology

Thorazine

Very first psychotropic drug (1951), initially developed for postoperative patients (shock and nausea)

Neurotransmitters

chemicals which transmit messages from one nerve cell to another

Genetics

• 1950’s investigative studies suggested that there is a strong genetic loading for mental illness

• Genetic factors are expressed biochemically

• Genetic loading especially for schizophrenia and bipolar disorder

Promedication (antipsychophtherapy) arguments

• Quantifiable, so medication treatment can be studied much more systematically.

• Medications act quickly and can therefore help restore hope and reduce demoralization

• Can help patients who have limited intellectual capacity, ego strength, or both (where psychotherapy would be appropriate)

• Medications are much more cost effective and more readily available to the general public, and have more thorough efficacy studies.

Pro-psychotherapy (antimedication) arguments

• Only psychotherapy, not medications can address the complexity of human psychological functioning

• Psychotherapy aims toward personal growth and autonomy, whereas drugs can foster dependency

• Drugs can interfere with autonomy and expressions of free will, but psychotherapy honors these things

• Many drugs have undesirable or dangerous side effects

• Medications ultimately do not solve problems, teach adaptive coping skills, mend broken hearts, or fill empty lives

Central thesis of current psychopharmacology

A sin for understanding and treating mental disorders narrow and is inadequate

While the majority of mental health services are provided by nonmedical therapists:

The majority of prescrptions for psychotropic mediations are written by family practice and primary care physicians (Nonpsychiatric MDs).

Neurobiology

• The human brain contains approoximately 100 billion nerve cells.

• Neuronal structure

• Neurotransmitter molecules are manufractured in the cell body (soma)

Neurotransmitters

In intercellular communication, nerve cells almost never touch each other.

Space between: synapse

When neurotransmitters are released into the synapse they:

• bind to receptors

• are chemically destroyed

• are reabsorbed (reuptake)

Conduction and Transmission

Ligands: bind to and active receptors

Neurotransmitters, hormones, and certain drugs

Resting-activation

An activation potential can be defined as the activition of excitatory receptors on dendrites

Conduction: movement along axon

Transmission: passing across synapse

Receptor Binding and Function

Neurotransmitters only bind to specific receptors

Function: excitatory or inhibatory

Reuptake inhibition:

• passed on, or

• manufacture more

Most nerve cells have 2,000-3,000 receptors on surface of cell dendrites (genetics)

Lifespan of receptors: 12-24 hours

Neuronal Malfunction

• Initial production of NTs may be inhibited

• NTs degraded by enzymes (e.g MAO)

• Disorders or drugs can inhibit release of NTs from presynaptic boutons

• Reuptake absorption

• Receptors abnormally up-regulated or down-regulated (stress)

Brain Structures

• Brain stem, central core, cerebral cortex

• Hypothalamus (regulation) 5 F’s

1. Fever

2. Feeding

3. Fun

4. Fight, flight, freeze

5. Fornication

• Limbic system: appraisal of emotional stimuli, initiation of emotional responses, shutting down reactivity

CNS & PNS

• CNS (brain and spinal cord)

• PNS (peripheral nervous system)

• Somatic (voluntary)

• Autonomic (involuntary)

• Sympathetic (mediated by norepinephrine)

• Parasympathetic (mediated by acetylcholine)

Pharmacokinetics

Drug: any substance that brings about change in biological function through its chemical reactions

Pharmacodynamics

The drug’s effect on the body

pharmacokinetics

the body’s effect on the drug-absorption, distribution, biotransformation, and excretion

Pharmacokinetics Factors

• Absorption-most drugs are absorbed in the stomach (or small intestine)

• Distribution-once absorbed drug reaches the bloodstream to be distributed to various organs or sites of action

• Biotransformation-Metabolism, occurs in liver, enzymes change compound

• Excretion-drugs eliminated from the body

Half-Life

The amount of time required for the serum concentration of a drug to be reduced by 50% (used to determine dosage amounts and intervals)

Steady State:

When concentrations for a drug in the bloodstream have reached a plateau (amount administered =amount eliminated), attained after 4 half lives.

Medication Effects

Pharmacological effect: The desired therapeutic effect

Side effects: typically undesirable effects, like constipation or blurry vision

Idiosyncratic effects: extremely rare, adverse effects that are difficult to predict

Allergic reactions: immune response to meds (rash, hypersensitivity anaphylaxis)

Discontinuance syndrome: response to stopping or interruption drug treatment