Chapter 2 Neurobiology Theories and Psychopharmacology PDF

CHAPTER 2 | NEUROBIOLOGIC THEORIES AND EXTRAPYRAMIDAL SYMPTOMS (EPSs) PSYCHOPHARMACOLOGY - serious neurologic symptoms, are the major side effects of antipsycho...

CHAPTER 2 | NEUROBIOLOGIC THEORIES AND EXTRAPYRAMIDAL SYMPTOMS (EPSs) PSYCHOPHARMACOLOGY - serious neurologic symptoms, are the major side effects of antipsychotic drugs AKATHISIA - they include acute dystonia, pseudoparkinsonism, and - an intense need to move about akathisia ANTICHOLINERGIC SIDE EFFECTS HALF-LIFE - often occur with the use of antipsychotics and include - is the time it takes for half of the drug to be removed from orthostatic hypotension, dry mouth, constipation, urinary the bloodstream hesitance or retention, blurred near vision, dry eyes, photophobia, nasal congestion, and decreased memory KINDLING PROCESS - This can be described as the snowball-like effect seen when ANTIDEPRESSANT DRUGS minor seizure activity seems to build up into more frequent - are primarily used in the treatment of major depressive and severe seizures illness, anxiety disorders, the depressed phase of bipolar disorder, and psychotic depression LIMBIC SYSTEM - is an area of the brain located above the brain stem that ANTIPSYCHOTIC DRUGS includes the thalamus, hypothalamus, hippocampus, and - formerly known as neuroleptics, are used to treat the amygdala symptoms of psychosis, such as the delusions and hallucinations seen in schizophrenia, schizoaffective disorder, MAGNETIC RESONANCE IMAGING (MRI) and the manic phase of bipolar disorder - a type of body scan, an energy field is created with a huge magnet and radio waves ANXIOLYTIC DRUGS - The energy field is converted to a visual image or scan - are used to treat anxiety and anxiety disorders, insomnia, obsessive-compulsive disorder (OCD), depression, MOOD-STABILIZING DRUGS posttraumatic stress disorder, and alcohol withdrawal - are used to treat bipolar disorder by stabilizing the client’s mood, preventing or minimizing the highs and lows that BLACK BOX WARNING characterize bipolar illness, and treating acute episodes of - means that package inserts must have a highlighted box, mania separate from the text, which contains a warning about the serious or life-threatening side effects NEUROLEPTIC MALIGNANT SYNDROME - is a potentially fatal idiosyncratic reaction to an COMPUTED TOMOGRAPHY (CT) antipsychotic (or neuroleptic) drug - also called computed axial tomography, is a procedure in - The major symptoms of NMS are rigidity; high fever; which a precise x-ray beam takes cross-sectional images autonomic instability such as unstable blood pressure, (slices) layer by layer diaphoresis, and pallor; delirium; and elevated levels of enzymes, particularly creatine phosphokinase DEPOT INJECTION - a time-release form of intramuscular medication for NEUROTRANSMITTERS maintenance therapy - are the chemical substances manufactured in the neuron that aid in the transmission of information throughout the DOPAMINE body - a neurotransmitter located primarily in the brain stem, has been found to be involved in the control of complex NOREPINEPHRINE (NORADRENALINE) movements, motivation, cognition, and regulation of - most prevalent neurotransmitter in the nervous system, is emotional responses located primarily in the brain stem and plays role in changes in attention, learning and memory, sleep and wakefulness, DYSTONIA and mood regulation - includes muscular rigidity and cramping, a stiff or thick tongue with difficulty swallowing, and, in severe cases, OFF-LABEL USE laryngospasm and respiratory difficulties - a drug will prove effective for a disease that differs from the one involved in original testing and FDA approval EFFICACY - refers to the maximal therapeutic effect that a drug can POSITRON EMISSION TOMOGRAPHY (PET) / SINGLE- achieve PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT) - are used to examine the function of the brain EPINEPHRINE (ADRENALINE) - Radioactive substances are injected into the blood; the flow - derivative of norepinephrine of those substances in the brain is monitored as the client - controls the fight or flight response in the peripheral performs cognitive activities as instructed by the operator nervous system - PET uses two photons simultaneously; SPECT uses a single photon POSTINJECTION DELIRIUM/SEDATION SYNDROME - includes sedation, confusion, disorientation, agitation, and cognitive impairment that can progress to ataxia, convulsions, weakness, and hypertension, which can lead to arrest POTENCY - describes the amount of the drug needed to achieve that maximum effect; low-potency drugs require higher dosages to achieve efficacy, while high-potency drugs achieve efficacy at lower dosages PSEUDOPARKINSONISM - drug-induced parkinsonism - Symptoms resemble those of Parkinson disease and include a stiff, stooped posture; masklike facies; decreased arm swing; a shuffling, festinating gait (with small steps); cogwheel rigidity (ratchet-like movements of joints); drooling; tremor; bradycardia; and coarse pill-rolling movements of the thumb and fingers while at rest PSYCHOIMMUNOLOGY - a relatively new field of study, examines the effect of psychosocial stressors on the body’s immune system PSYCHOPHARMACOLOGY - use of medications to treat mental illness REBOUND - temporary return of symptoms SEROTONIN - is derived from tryptophan, a dietary amino acid - serotonin is mostly inhibitory, and it is involved in the control of food intake, sleep and wakefulness, temperature regulation, pain control, sexual behavior, and regulation of emotions SEROTONIN SYNDROME - (or serotonergic syndrome) can result from taking an MAOI and an SSRI at the same time STIMULANT DRUGS - specifically amphetamines, were first used to treat pyschiatric disorders in the 1930s for their pronounced effects on CNS stimulation TARDIVE DYSKINESIA (TD) - a syndrome of permanent involuntary movements, is most commonly caused by the long-term use of conventional antipsychotic drugs WITHDRAWAL - new symptoms resulting from discontinuation of the drug  NERVOUS SYSTEM AND HOW IT WORKS - it receives and integrates information from all areas of the body, such as the muscles, joints, organs, and other CENTRAL NERVOUS SYSTEM components of the CNS - it comprises of: - inhibited transmission of Dopamine: lack of smooth  Brain coordinated movements in diseases such as Parkinson  Spinal cord disease and dementia  Associated nerves that control voluntary acts BRAIN STEM CEREBRUM - includes: - divided into two hemispheres:  Midbrain A) Left Hemispheres  Pons - controls the right side of the body  Medulla oblongata - center for logical reasoning and analytic  Nuclei for cranial nerves III through XII functions such as reading, writing, and mathematical tasks Medulla Oblongata - located at the top of the spinal cord B) Right Hemispheres - contains vital centers for respiration and cardiovascular - controls the left side of the body functions - center for creative thinking, intuition, and artistic abilities Pons - above the medulla and in front of the cerebrum Pineal Body / Gland - bridges the gap both structurally and functionally, serving as - located between the hemispheres a primary motor pathway - an endocrine gland that influences the activities of the pituitary gland, islets of Langerhans, parathyroid, adrenals, Midbrain and gonads - connects the pons and cerebellum with the cerebrum - measures only 0.8 in (2 cm) length Corpus Callosum - includes most of the reticular activating system and the - a pathway connecting the two hemispheres and extrapyramidal system coordinating their functions a. Reticulating Activating System - divided into four lobes: - influences motor activity, sleep, consciousness, and awareness A) Frontal - control the organization of thought, body b. Extrapyramidal System movement, memories, emotions, and moral - relays information about movement and behavior coordination from the brain to the spinal nerves - abnormalities:  Schizophrenia Locus Coeruleus  Attention-deficit/hyperactivity disorder - a small group of norepinephrine-producing neurons in the (ADHD) brain stem  Dementia - associated with stress, anxiety, and impulsive behavior B) Parietal LIMBIC SYSTEM - interpret sensations of taste and touch - an area of the brain located above the brain stem that - assist in spatial orientation includes:  Thalamus C) Temporal  Hypothalamus - centers for the senses of smell and hearing  Hippocampus - for memory and emotional expression  Amygdala D) Occipital Thalamus - assist in coordinating language generation - regulates activity, sensation, and emotion and visual interpretation, such as depth perception Hypothalamus CEREBELLUM - involved in temperature regulation, appetite control, - located below the cerebrum endocrine function, sexual drive, and impulsive behavior - center for coordination of movements and postural associated with feelings of anger, rage, or excitement adjustments Hippocampus and Amygdala - are involved in emotional arousal and memory Disturbances: Neuropeptides Neuromodulators Enhance, prolong,  Memory loss that accompanies dementia inhibit, or limit the  Poorly controlled emotions and impulses seen with effects of principal psychotic or manic behavior neurotransmitters Glutamate Excitatory Results in NEUROTRANSMITTER neurotoxicity if levels are too high - 100 billion cells form groups of neurons, or nerve cells, that y-Aminobutyric Inhibitory Modulates other are arranged in networks Acid neurotransmitters Neurotransmission - neurons communicate information with one another by MAJOR NEUROTRANSMITTERS sending electrochemical messages from neuron to neuron 1. Dopamine - dendrites: projections from the cell body - a neurotransmitter located primarily in the brain stem, - axon: long extended structures has been found to be involved in the control of complex - synapses: gaps between cells movements, motivation, cognition, and regulation of emotional responses NEUROTRANSMITTERS - synthesized from tyrosine, a dietary amino acid - are the chemical substances manufactured in the neuron that aid in the transmission of information throughout the  Schizophrenia body  Parkinson disease - excitatory: excite or stimulate an action in the cells  Antipsychotic medications: work by blocking - inhibitory: inhibit or stop an action dopamine receptors and reducing dopamine activity MAJOR NEUROTRANSMITTERS 2. Norepinephrine and Epinephrine Type Mechanism of Physiologic Action Effects Norepinephrine/ Noradrenaline Dopamine Excitatory Controls complex - most prevalent neurotransmitter in the nervous movements, system motivation, - located primarily in the brain stem and plays a role in cognition; changes in attention, learning and memory, sleep and regulates wakefulness, and mood regulation emotional response  excess: Norepinephrine Excitatory Causes changes in  Anxiety disorders (noradrenaline) attention, learning  deficit: and memory,  memory loss sleep, and  social withdrawal wakefulness,  depression mood Epinephrine Excitatory Controls fight or Antidepressants: block the reuptake of norepinephrine (adrenaline) flight response Serotonin Inhibitory Controls food Epinephrine / Adrenaline intake, sleep, and - derivatives of norepinephrine wakefulness, - controls the fight or flight resposne in the PNS temperature regulation, pain 3. Serotonin control, sexual - derived from tryptophan, a dietary amino acid behaviors, - involved in the control of food intake, sleep and regulation of wakefulness, temperature regulation, pain control, emotions sexual behavior, and regulation of emotions Histamine Neuromodulator Controls alertness, gastric secretions, 4. Histamine cardiac - psychotropic drugs: block histamine, resulting in stimulation, weight gain, sedation, and hypotension peripheral allergic responses 5. Glutamate Acetylcholine Excitatory or Controls sleep and - has been implicated in the brain damage caused by inhibitory wakefulness cycle; stroke, hypoglycemia, sustained hypoxia or ischemia, signals muscles to and some degenerative diseases such as Huntington or become alert Alzheimer  Three types of studies are commonly conducted to 6. Gamma-Aminobutyric Acid investigate the genetic basis of mental illness: - drugs that increase GABA: benzodiazepines - used to treat anxiety and to induce sleep 1. Twin Studies: are used to compare the rates of certain mental illnesses or traits in monozygotic CRANIAL NERVES (identical) twins, who have an identical genetic Number Function Function makeup, and dizygotic (fraternal) twins, who have a I Olfactory Sensory: smell different genetic makeup II Optic Sensory: vision III Oculomotor Motor: movement of Fraternal twins: have the same genetic similarities and the eyeball, regulation differences as nontwin siblings of the size of the pupil IV Trochlear Motor: eye movements 2. Adoption Studies: are used to determine a trait V Trigeminal Sensory: sensations of among biologic versus adoptive family members head and face, muscle sense 3. Family Studies: are used to compare whether a Motor: mastication trait is more common among first-degree relatives VI Abducens Motor: movement of (parents, siblings, and children) than among more the eyeball, particularly distant relatives or the general population abduction VII Facial Sensory: taste 2) STRESS AND IMMUNE SYSTEM (PSYCHOIMMUNOLOGY) Motor: facial expressions, secretions Psychoimmunology of saliva - a relatively new field of study, examines the effect of VIII Vestibulocochlear Sensory: balance, psychosocial stressors on the body’s immune system hearing - a compromised immune system could contribute to the IX Glossopharyngeal Sensory: taste development of variety of illnesses Motor: swallowing, secretion of saliva 3) INFECTION AS A POSSIBLE CAUSE X Vagus Sensory: sensation of - theories that are being developed and tested: organs supplied  Existence of a virus that has an affinity for tissues Motor: movement of of the CNS organs supplied  The possibility that a virus may actually alter XI Accessory Motor: shoulder human genes movement, turning of  Maternal exposure to a virus during critical fetal head, voice production development of the nervous system XII Hypoglossal Motor: tongue movements NEUROBIOLOGIC CAUSES OF MENTAL ILLNESS 1) GENETICS AND HEREDITY - gene SORL1: may be a factor in late-onset Alzheimer disease - National Human Genome Research Institute (1988) - funded by the National Institutes of Health and the US Department of Energy - (encoding): has identified all human DNA and continues with research to discover the human characteristics and diseases to which each gene is related - Ethical, Legal, and Social Implications (ELSI) - focuses on privacy and fairness in the use and interpretation of genetic information, clinical integration of the new genetic technologies, issues surrounding genetics research, and professional and public education