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Glossary
Adrenaline - the neurotransmitter also known as epinephrine, released by the adrenal glands to activate bodily systems as part of the fight-flight response. Adrenocorticotrophic hormone (ACTH) - a substance released by the pituitary gland that travels to the adrenal glands, causing the release of cortisol. Afferent nerves - nerves that send sensory information from sensory receptors to the central nervous system. Amygdala - an almond-shaped structure in the limbic system that helps regulate rage, aggression and sexual behavior as well as feelings of affection and is believed to be involved in depression. Antidepressants - prescription medications that can be effective in reducing symptoms of depression. Asylum - facility common in the past where the mentally ill were kept in isolation and received limited care. Autonomic nervous system - network of nerves from the central nervous system to the internal organs that controls involuntary responses such as heart rate, blood pressure, digestion, and breathing. Axon - projection at opposite end of the neuron from dendrites; sends information in the form of neurotransmitter substances to another nerve cell. Biogenic - caused by biological factors. Bi-directional causation - concept that biological processes (such as those of the brain, immune system or genes) and behavior and mental processes mutually influence each other. Bipolar disorder - a type of mood disorder once called manic-depression, in which an individual alternates between periods of extreme depression and mania. Body humors - substances once believed to exist in the body, imbalances of which were believed to cause disease, including mental disorders. Cartesian (mind-body) dualism - Rene Descartes’ concept that there are two types of elements: 1) physical matter, which is in the realm of science and can be measured by scientists, and 2) spiritual or mental matter, which has no physical properties and can not be measured by science, but is the domain of religion and the church. Central nervous system - portion of the nervous system comprised of the brain, spinal cord and brain stem, which is the lower extension of the brain, connecting it to the spinal cord. Cerebellum - located in the hindbrain, it plays a vital role in muscle coordination, motor behavior and integration of movement, as well as non-motor functions such as speech, learning, emotions, and attention. Cerebral cortex - (also known as “neocortex” or “cortex”) the deeply wrinkled outermost layer of the brain; involved in higher mental processes such as reasoning, planning, memory, and speech - that is, thinking in general. Chemical imbalance - a predominant neurobiological theory that an excess or deficit of specific neurotransmitters causes, or is strongly linked to, mental illness. Cingulate cortex - brain structure and part of the limbic system that affects awareness of mood state and is believed to play a role in depression. Cognitive-behavioral therapy (CBT) - a type of psychotherapy that helps a person recognize and change negative styles of thinking and behaving that are often associated with mental or emotional dysfunction. Cognitive distortions - pessimistic and unrealistic ways of thinking about oneself, others, the future and the world that, if habitual, can contribute to mental or emotional dysfunction. Co-morbidity - having more than one illness at the same time. Corpus callosum - band of tissue between the left and right hemispheres of the brain that acts as a conduit for, and integrator of, information between the two sides of the brain. Corticotrophin releasing factor (CRF) - a hormone released by the hypothalamus that stimulates the pituitary gland to release corticotrophin as part of the HPA feedback loop. Cortisol - a long-acting stress hormone, which at moderate levels (when the HPA axis is functioning normally) facilitates a variety of bodily processes, but in excess can be damaging and put one at risk of stress and depression. Course -progression of a disease over time with respect to severity and symptoms. Dendrite - projection at one end of the neuron that accepts incoming information in the form of neurotransmitter substances from an adjacent nerve cell. Diaphragm - muscle tissue in the lower abdomen that is essential to breathing. Diaphragmatic breathing - type of breathing that involves the conscious use of the diaphragm to produce deep, efficient breathing associated with a calm, relaxed state. Diathesis-stress model of illness - theory that the interaction of stress and an inherited vulnerability to a particular type of disease causes illness (stress + genetic/biological vulnerability = illness). Discrimination - the act of making a difference in treatment or favor on a basis other than individual merit. Distress - experiencing more stress than we can effectively cope with. Dysthymia - a type of depressive disorder that is milder than major depressive disorder, but is chronic - lasting at least two years for adults and one year for children and adolescents. Efferent nerves - nerves that send impulses from the brain to direct voluntary activity of the muscles. Electroconvulsive therapy/shock therapy (ECT) - a form of treatment for depression in which mild electrical stimulation is applied to the brain; considered a safe, accepted form of treatment, especially for severe depression that does not respond to other treatment strategies. Eustress - effort without distress; having the capacity to cope. Exorcism - a religious ritual whose purpose is removal of an evil spirit believed to be inhabiting a person’s body and causing mental illness. Experimental method - An approach used in research, in which a hypothesis is tested under controlled conditions to determine a relationship (possibly causal) between two or more variables. Fight-flight response - an automatic physiological reaction to danger that involves activation of some bodily systems via the sympathetic nervous system. back to top Forebrain - a number of brain structures, including the cerebral cortex, involved with higher mental functions as well as some of the more animalistic ones, such as the “fight-flight” response, aggression, eating, and sex. Frontal lobe - located at the front of the neo-cortex behind the forehead, this major division of the cortex deals with the most advanced human functions. The most forward segments, the prefrontal lobes, are associated with complex thought processes, such as planning, anticipation, judgment, problem solving and inhibition of impulses. Gyri - folds or ridges on the outermost layer of the cerebral cortex. Herbal treatments - non-FDA approved, but legally available, preparations derived from plants that are sometimes used as alternatives to pharmaceutical drugs for the treatment depression or other types of emotional problems. Hindbrain - located about where the spinal cord comes into the brain, this region is considered the most primitive part of the brain; it is responsible for most bodily functions that maintain life. Hippocampus - a brain structure located in the limbic system that is critical to memory, learning and emotions and seems to have a role in helping “cement” some memories into place for events with strong emotional meaning; it is reduced in size in some individuals who are depressed. Homeostasis - the state in which all systems in the body are functioning normally and smoothly, and there is no net loss of energy or ability to cope. Hypothalamic-pituitary-adrenal (HPA) axis - a process that is part of the body’s stress response, involving the hypothalamus and the pituitary and adrenal glands in a feedback loop; when this system is impaired, depression can result. Hypothalamus - brain structure that serves as the integration center of the autonomic nervous system, regulating hormones, appetite, sleep, libido (sexual interest), the fight-flight response, and the capacity to experience pleasure, and is believed to play a role in depression. Inhibitory and excitatory impulses - two types of messages sent by neurons via neurotransmitters; inhibitory impulses lower the chance that the receiving neuron will reach a critical threshold and fire, whereas excitatory impulses move the neuron toward its critical level for firing. Integrative model - concept of illness as a product of complex interactions among multiple factors (biological, neurological, genetic, environmental, cultural, and social). Interpersonal therapy (IPT) - a type of psychotherapy that helps a person improve unhealthy personal relationships that may cause, worsen or contribute to a mental or emotional dysfunction. Left hemisphere - left side of the brain, mainly involved in sequential thinking (processes information primarily in analytical and logical ways) and verbal functions. Limbic system - region deep within the brain that includes the hypothalamus, hippocampus, and amygdala and plays an important role in emotional, sexual, and survival functions. It has many connections to the cerebral cortex and to the endocrine and autonomic systems. Locus coeruleus - part of the brain stem that is a site for the manufacture of norepinephrine. Major depressive disorder - a severe type of depressive disorder, often recurrent, characterized by at least two weeks of persistent sad mood, loss of interest in activities or pleasure, and at least four other symptoms of depression. Mania - an extreme in mood, the opposite of depression, characterized by highly energetic, driven behavior and thinking, with possible symptoms including grandiose expectations, little need for sleep, and involvement in high-risk activities. Medulla - part of the hindbrain where the spinal cord joins the brain stem; helps regulate basic functions such as heartbeat and respiration. Meninges - membranes that encase the brain, providing protection. Midbrain - area of the brain that serves as the relay center between the hindbrain and the forebrain, sending stimuli to higher brain centers. Monoamines - a type of neurotransmitter made from amino acids, a basic element of protein. Mood disorder - a type of mental disorder characterized by disturbance of normal mood (feeling), such as depression. Myelin - a covering around the axons of the neurons that facilitates transmission of nerve impulses. Nature-nurture - refers to a long-standing philosophical debate over whether the causes of behavior or mental illness are primarily biological (genetics, brain injury, or medical conditions) or environmental (learning acquired by a person’s experiences through the exercise of free will in his or her physical, social and cultural environments). Neuron - nerve cell, the basic building block of the nervous system, which communicates through neurotransmitter exchanges. Neurotransmitter - chemical substance in the nervous system that is exchanged by neurons, transmitting information within the brain and from the brain to the rest of the body. Norepinephrine - a monoamine neurotransmitter that appears to play a role in regulation of mood, released from the adrenal gland. Occipital lobe - at the back of the brain, this major division of the cortex processes visual sensations of all kinds, including colors and shapes. Outcome -the effects of a disease at the end of its course (possible outcomes: complete recovery, impaired function, or death). Parasympathetic nervous system - maintains the body at homeostasis (moves it from the “fight or flight” mode back to the “maintenance” mode). Parietal lobe - located at about midpoint in the top of the brain, this major division of the cortex processes sensory input and has a critical role in verbal and spatial reasoning and musical sound recognition. Peripheral nervous system - all nerves and neurons in the body other than those in the brain, brain stem, and spinal cord. Pons - part of the hindbrain where the spinal cord joins the brain stem; helps regulate basic functions such as heartbeat and respiration. Postpartum depression - a type of mood disorder similar to major depression that sometimes occurs in women following childbirth. Prefrontal area - brain structure and most forward part of the frontal lobe of the cerebral cortex; helps with regulation of emotions and is believed to play a role in depression. Prevalence - the frequency of occurrence of a disorder in a population. Pruning - a natural process that causes neural circuits to wither away and die from lack of use, especially important during the early stages of neural development, particularly during the first two years of life. Psychogenic - caused by psychological factors. back to top Psychotic/psychosis - relates to mental disorders in which a person becomes incapable of distinguishing between reality and non-reality; examples include delusions (beliefs that are demonstrably unreal, such as that one is being plotted against by the world) or hallucinations. Psychotherapy - also known as “talk therapy,” the treatment of mental disorders or other psychological problems by counseling. Raphe nucleus - part of the brain stem that produces serotonin. Receptors/receptor site - point on a cell wall that receives neurotransmitter molecules from adjacent cells. Reticular activating system (RAS) - network of neurons mostly within the brainstem that helps regulate attention and arousal levels (sleep and wakefulness, consciousness). Reuptake - process by which the reuptake pump removes neurotransmitter molecules from the synaptic cleft, returning them to the neuron. Reuptake pump - a structure in the neuron that removes neurotransmitter molecules from the synaptic cleft. Right hemisphere - right side of the brain, primarily involved with nonverbal (e.g. spatial, visual, mechanical, emotional) mental functions; simultaneously processes multiple types of stimuli in a holistic, intuitive way. Risk factors - variables associated with a higher risk of developing a disorder. Seasonal affective disorder - a type of depression that results from reduced exposure to sunlight during the fall and winter. Selective serotonin reuptake inhibitors (SSRIs) - newer antidepressant medications that are thought to work by decreasing reuptake of serotonin, making more available for neurotransmission. Sensory cortex - an area in the parietal lobe that controls perception of touch and pressure and fine discriminations such as judgment of texture and size. Somatic nervous system - the part of the nervous system involved in sensory and motor functions; its neurons conduct impulses back and forth between the central nervous system and the rest of the body. Stereotype - simplistic and biased portrayal of a cultural group, such as the mentally ill, often arising from ignorance or fear. Stigma/stigmatization - unwarranted negative attitudes about or behaviors toward persons with particular characteristics, in this case, mental illness. St. John’s Wort - a type of plant and herbal treatment widely used to treat depression, although recent research has found it to be ineffective for this purpose. Stress - the responses of a person to any demands that are sufficient to disturb homeostasis; the stress response tries to keep one’s systems in homeostasis. Stressor - any event that requires us to change or adapt. Sympathetic nervous system - system that controls the body’s survival mode, also known as the “fight or flight” response, by regulating internal organs under conditions of high stress. Substance-induced mood disorder - a type of mood disorder caused by exposure to a substance, such as an environmental toxin, medication or illicit drug. Sulci - fissure on the outermost layer of the cerebral cortex. Synapse - junction between two adjacent nerves, where the activity of one cell affects another. Synaptic cleft - narrow gap between adjoining cells, where neurotransmitters flow from one cell to another. Synaptic plasticity - the brain’s capacity to establish or strengthen neural connections from repeated use, increasing the likelihood that a particular pathway will be used again. Synaptic vesicle - structure that transports neurotransmitters from point of manufacture to the terminal buttons from which they are released into the synaptic gap. Temporal lobes - located on each side of the head at about ear level, this major division of the cortex processes language and auditory and olfactory input; also play a role in sorting of information, believed to be an important aspect of short-term memory. Terminal buttons - located on the ends of axons, these sites release neurotransmitters into the synaptic cleft to be picked up by a receptor site on an adjacent neuron. Thalamus - structure within the forebrain that relays and integrates information sent to the cerebral cortex from other parts of the brain. Transcranial magnetic stimulation (TMS) - a promising but still experimental treatment for depression using a high-intensity magnetic field briefly applied to the scalp to alter neuronal function in the area of the brain beneath. Trephining - a process used several thousand years ago, when mental illness was believed to be caused by evil spirits, in which holes were drilled in the skull of a person to allow the “evil spirit” to leave the body. Tricyclic antidepressants (TCAs) - some of the first antidepressant medications, which worked by affecting activities of the monoamine neurotransmitters serotonin and norepinephrine. Visual imagery - a stress-relaxation technique that involves imagining a calming scene, building in many details, to make it seem real. Yerkes response curve - an inverted U-shaped curve that graphically represents the relationship between varying stress levels and performance. If stress is low, performance improves with an increase in stress, but at very high levels of stress, the effect is reversed, resulting in declining performance. back to top
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