Sadness is a transient emotional state that is generally associated with negative moods and unhappy feelings.

Sanity a term used more colloquially than otherwise in recent years, can be understood to refer to the state of having a sound, rational mind and being capable of good judgment. This term is outdated in the field of mental health and is no longer in general use, but it is still used in a legal context.

Scapegoat is a person, group, or entity who is targeted for blame for something he or she was not responsible for.

Schizophrenia is characterized by a disintegration of thinking processes and emotional responsiveness. It is most commonly manifested through delusions, auditory hallucinations, disorganized thinking and speech, and paranoid delusions and may affect social or occupational functioning depending on symptoms and severity. Finding a therapist or counselor to work with can help those affected with schizophrenia to increase social skills, develop higher self-esteem, and gain insight to the mental health issues accompanying the condition.

School and Academic Concerns which might include issues such as learning difficulties or disabilities, underachievement, lack of attention from teachers, and bullying, affect a number of students throughout their academic careers, from elementary school to college. Academic concerns may influence a student’s performance in the classroom negatively, but they are also likely to have a significant effect on other areas of life, often placing undue stress on a child and interfering with home, work, and play dimensions. A student who experiences some type of academic concern may benefit from speaking to a mental health professional.

School Counseling takes place in public and private school settings in grades K-12. Counseling is designed to facilitate student achievement, improve student behavior and attendance, and help students develop socially. Mental health professionals with master’s degrees or beyond, school counselors both provide counseling and serve an educational role in and around schools. Many schools have full-time counselors on staff in order to support students who are experiencing personal or academic challenges, help students choose careers and plan for college, and intervene when students face behavioral, physical, or mental health challenges.

Scientific Method is a set of formulaic guidelines for gathering scientific data, reaching conclusions, and establishing theories. Because mental health significantly affects people’s lives, scientifically tested methods are particularly important. Pseudoscientific ideas and methods are those that have not been validated through rigorous testing and the scientific method. Examples of pseudoscientific theories include ideas that cannot be disproven or validated, theories that are not backed by evidence, and ideas based upon researcher opinion and conjecture.

Seasonal Affective Disorder (SAD) is a mood condition affected by changes in season. It is a type of depression usually linked to fall and winter months, although for a small number of people it can occur in spring and summer. Available treatment options for this condition include light therapy (phototherapy), nutritional changes, and psychotherapy with or without medication.

Selective Norepinephrine Reuptake Inhibitors (SNRIs) Also known as dual-uptake inhibitors, serotonin and norepinephrine reuptake inhibitors (SNRIs) are commonly prescribed by physicians and psychiatrists to treat depression and anxiety. SNRIs, developed in the mid-1990s, are very similar to another category of antidepressants known as selective serotonin reuptake inhibitors (SSRIs), but they have a slightly broader effect on chemical processes in the brain, and some individuals who do not respond to SSRIs may benefit from an SNRI. Studies have shown that SNRIs may be slightly more effective than SSRIs but that they may cause more side effects in some individuals.

Selective Serotonin Reuptake Inhibitors (SSRIs) are the most frequently prescribed category of antidepressants. These medications have a strong reputation for both safety and effectiveness. Developed in the past 20 years, SSRIs are typically the first choice for physicians when treatment requires the prescription of antidepressants. Unlike many tricyclic antidepressants, SSRIs have less affinity for α-adrenergic, histamine, and cholinergic receptors and thus produce fewer adverse effects than most other classes of antidepressants.

Self may refer to one’s conceptualization of his or her own personal identity. Depending on the theoretical framework, self can be defined in different ways. Self theory might include constructs like self-concept, personality, identity, and/or the makeup of one’s inner world.

Self Psychology an offshoot of Freud’s psychoanalytic theory, forms much of the foundation of contemporary psychoanalysis as the first large psychoanalytic movement recognizing empathy as an essential aspect of the therapeutic process of addressing human development and growth. Self psychology theory, which rejects Freudian ideology of the role sexual drives play in organization of the psyche, focuses on the development of empathy toward the person in treatment and the exploration of fundamental components of healthy development and growth. Therapists may use self psychology theory in part to help people consider how their early experiences may contribute to the formation of their sense of self.

Self Relations a relatively new therapeutic approach developed by Stephen Gilligan, focuses on the relationship individuals have with their inner self. According to this theory, psychological symptoms occur when the body and mind attempt to draw attention toward an area of dysfunction or impairment potentially requiring attention. A therapist trained in self-relations therapy can, through a process known as sponsorship, help people identify and apply skills to empower the self and heal.

Self-Acceptance Training, an educational, alternative approach to traditional therapy, aims to help people live rich, full lives through group workshop trainings. Practitioners of the approach attempt to evoke a hypnotic trance state in participants, as it is thought that individuals who are in this trance state may be less likely experience critical and/or negative self-evaluations that may interfere with the ability to pay attention to thoughts, imagery, and sensations. Individuals seeking therapy to develop greater awareness of the self and/or to pursue self-exploration in an environment free from criticism, judgment, and evaluation may find this approach beneficial.

Self-Actualization is the final stage of development in Abraham Maslow’s hierarchy of needs. This stage occurs when a person is able to take full advantage of his or her talents while still being mindful of his or her limitations. The term is also used colloquially to refer to an enlightened maturity characterized by the achievement of goals, acceptance of oneself, and an ability to self-assess in a realistic and positive way. Self-actualization can be explored in therapy.

Self-Care describes the actions that an individual might take in order to reach optimal physical and mental health. Mental health professionals often use the term self-care to refer to one’s ability to take care of the activities of daily living, or ADLs, such as feeding oneself, showering, brushing one’s teeth, wearing clean clothes, and attending to medical concerns. Physical self-care, such as sleep and exercise, is also an ADL. Self-care can also refer to activities that an individual engages in to relax or attain emotional well-being, such as meditating, journaling, or visiting a counselor. Because an extended failure to care for one’s self can result in illness or hospitalization, individuals who find themselves unable to take care of their own needs may find it helpful to speak to a therapist.

Self-Compassion is the ability to turn understanding, acceptance, and love inward. Many people are able to extend compassion toward others but find it difficult to extend the same compassion toward themselves. They may see self-compassion as an act of self-indulgence, but extending compassion toward oneself is not an act of self-indulgence, selfishness, or self-pity. In fact, self-compassion can help relieve many mental health concerns such as anxiety or insecurity. Many mental health professionals help people develop compassion for themselves.

Self-Confidence an internal state of mind, can describe the attitudes and beliefs people hold regarding their abilities and strengths. People who have high levels of self-confidence may feel sure they will achieve what they set out to do and maintain a steady sense of control over their lives. Self-confident people generally trust in their abilities, their power, and their judgment.

Self-Criticism, or the act of pointing out one’s perceived flaws, can be a healthy way to increase self-awareness and achieve personal growth, but it may also prove a barrier to one’s self-esteem and peace of mind. Self-criticism may often help facilitate the process of learning from one’s mistakes and can also be helpful when one attempts to overcome areas of weakness or unwanted habits. A high level of self-criticism that prevents individuals from taking risks, asserting opinions, or believing in their own abilities may be unhelpful or detrimental to well-being. Those experiencing these effects may wish may wish to address the reasons behind excessively self-critical tendencies with a therapist or other mental health professional.

Self-Doubt can be understood as a feeling of uncertainty regarding one or more aspects of the self, such as confidence or likability. Some degree of self-doubt is generally held to be normal, because many people may question their ability to master new or challenging situations. If self-doubt becomes debilitating, affects daily function, or impedes performance at work or school, a therapist or other mental health professional may be able to offer support and guidance.

Self-Efficacy is a person’s belief about whether he or she possesses the necessary skills to complete tasks and achieve goals.

Self-Esteem is the degree to which one feels confident, valuable, and worthy of respect. It exists on a continuum from high to low. Where a person’s self-esteem falls on this spectrum can influence one’s overall well-being. People with high self-esteem often feel good about themselves and their progress through life. People with low self-esteem often feel shame and self-doubt. They often spend lots of time criticizing themselves. Low self-esteem is a symptom of several mental health conditions, such as anxiety and depression. Low self-esteem is not represented as its own diagnosis in the APA’s Diagnostic and Statistical Manual (DSM-V). Yet its symptoms and effects are very real. People who wish to improve their self-esteem can get help from a therapist.

Self-Fulfilling Prophecy is a thought or expectation that manifests in a person’s life because it has been thought. For example, when a teacher assumes that a certain student is not intelligent, the teacher might give that student less positive attention and more negative attention, resulting in poorer performance by the student. The teacher, in turn, will have the original assumption about the child validated. Or a student interviewing for college might believe she will do poorly during the admission interview. Her anxiety over doing poorly might then cause her to do poorly at the interview, validating her negative self-assessment.

Self-Harm, or an injury inflicted on oneself, often by cutting or burning, is generally a sign of intense inner turmoil, anxiety, and/or suppressed emotions. Self-injuring behavior is not the same as a suicide attempt: Though some individuals who self-harm may attempt suicide, in general, acts of self-harm do not indicate a desire to end one’s life. A person might harm him or herself to express pain, anxiety, or other emotions or to maintain a feeling of control over his or her body when other situations in life seem outside his or her control. This behavior often develops in adolescence and, if left untreated, may continue for many years. If you are or a loved one is experiencing a crisis, in danger of hurting oneself or others, or feeling overwhelmed or suicidal, please find help immediately. Contact the National Suicide Prevention Lifeline at 1-800-273-8255 to speak with someone right away, or reach out to one of the other resources listed on this page.

Self-Help Groups, also sometimes referred to as mutual-help groups, are groups in which members share the same issue, condition, or situation and thus are in a position to provide help and support to each other. A variety of self-help groups exist to help people address a wide range of issues, including emotional concerns, physical disabilities, eating and food issues, addiction, bereavement, and illness.

Self-Love refers to the act of valuing one’s own happiness and well-being. Self-love is a kind of acceptance that can be described as an unconditional sense of support and caring and a core of compassion for the self. It might also be considered a willingness to meet personal needs, allow non-judgmental thinking, and view the self as essentially worthy, good, valuable, and deserving of happiness. Those who find it challenging to practice self-love or have barriers that make it difficult for them to experience compassion or love for themselves may find the support of a therapist or other mental health professional to be beneficial as they explore the reasons behind these difficulties.

Self-Serving Bias is a cognitive bias that causes a person to view their own actions favorably or interpret events in a way that is beneficial to themselves. It typically occurs when a person attributes his or her successes to his or her own abilities but any failures to external causes.

Selfishness is the tendency to prioritize one’s own desires and needs above the needs and desires of other people.

Sensitivity to Criticism may lead an individual to be negatively impacted by any criticism, even when that criticism is constructive and intended to be helpful. Criticism can sting in any situation, whether the individual criticized believes in the truth of critical comments or knows such comments to be false. Many individuals are able to consider and integrate helpful criticism and experience no lasting effect from it. Experiencing anxiety, depression, anger, shame, or extreme defensiveness when faced with criticism may indicate a high level of sensitivity. When one finds it difficult to cope with criticism or finds oneself constantly revisiting an instance of criticism, it may be helpful to address this sensitivity with a therapist or other mental health professional.

Sensory Processing Disorder (SPD), also known as Sensory Integration Dysfunction, is a condition that causes difficulty with processing and organizing sensory information. This impairment can lead to a variety of issues, including clumsiness, behavioral concerns, and anxiety. It can be severe enough to interfere with daily functioning.

Serotonin is a neurotransmitter—a chemical that carries nerve signals. It is manufactured in the brain and located throughout the body, particularly in the digestive system and blood platelets. Serotonin is best-known for its association with mood and feelings of pleasure.

Sex Addiction is any compulsive, sexually motivated behavior that is acted out regardless of any negative consequences that the behavior might have on one’s life. The condition began to be addressed as an actual mental health concern in the 1980s, and though there are claims that it is not a valid illness, an addiction to sex can interfere with daily life, and treatment can readily be sought from a mental health professional.

Sex Education, sometimes referred to as sexuality education, is any process dedicated to providing information about sexual techniques, practices, and health or human sexuality. However, the term is usually used to refer to sex education for children—either at home or in school.

Sexism is prejudice or discrimination based on a person’s sex. Anything from demeaning comments and gestures to denying access to equal opportunities based on sex may be considered sexist, as well as treating someone as less competent because of his or her sex, whether in the workplace or classroom, on the streets, or at home. Typically, sexist remarks, behavior, and perspectives are thought of as being targeted at women, who are largely afforded less privilege than men.

Sexting is a colloquialism used to refer to the sending of sexually explicit items, particularly photos and videos, via text message. Due to widespread cell phone use, sexting is becoming increasingly common among both adults and teens. Though the types of messages consenting adults send to each other generally are not subject to scrutiny, when underage teens send sexts, even to their peers, these messages can be considered child pornography.

Sexual Assault/ Abuse is any form of sexual violence, including rape, child molestation, incest, and similar forms of non-consensual sexual contact. Most sexual abuse experts agree sexual abuse is never only about sex. Instead, it is often an attempt to gain power over others. Immediate crisis assistance after sexual assault can prove invaluable and even save lives. A person can report sexual assault by calling local police. Survivors may also wish to get a physical exam at a hospital. Therapy can also be helpful for those who experienced sexual abuse in the past. Some therapists specialize in addressing the trauma of sexual assault. Long-term assistance may be beneficial to some survivors of sexual abuse.

Sexual Orientation characterizes a person’s inclination with regards to sexual attraction. Orientation is typically divided into three categories: Homosexuality is primary attraction to members of the same sex. Heterosexuality is attraction primarily to members of the opposite sex. Bisexuality is attraction to members of both sexes. Some sexuality theorists have proposed expanding the definition to include other sexual orientations such as asexuality, which is a lack of sexual interest in others; and pansexuality, which is an attraction to persons of all sexes and gender identities.

Sex and Sexuality refers to habits and preferences in terms of sexual behavior. People express it in many ways. Sometimes, people feel confusion or distress about their sexuality or sexual identity. They may seek help from a therapist.

Sex Therapy is a type of psychotherapy that addresses mental health issues and/ or emotional concerns affecting a person’s sexual function, drive, and/or desire for intimacy. These issues are typically explored with the help of a licensed sex therapist. Some people seek help individually, while others may pursue sex therapy with a romantic partner.

Shame a feeling of being unworthy, bad, or wrong—can be extremely uncomfortable. Shame has the potential to change the way we see ourselves and may lead to long-lasting social, professional, and sexual difficulties and also affect other areas of life. The word “shame” may mean different things to different people, and shame is different from guilt and embarrassment: Guilt is usually understood to involve negative feelings about an act one has committed, while embarrassment deals with a societal reaction. Shame, on the other hand, involves negative feelings about oneself, and although an individual can be shamed by peers or society in general, shame can also be experienced secretly. Shame that does not resolve, that cannot seem to be diminished or altered, can become a cause for clinical concern, and individuals experiencing severe shame regarding a particular issue may find benefit in speaking to a therapist.

Shyness a personality trait or emotional state, might be characterized by awkwardness, worry, or tension around other people, especially strangers. It is not a diagnosable mental health condition, but someone who wants to overcome shyness might seek psychotherapy to address it. Shyness is not synonymous with or linked to generalized anxiety, social anxiety, isolation, introversion, or agoraphobia, though someone with these issues might also be shy.

Sibling Issues Siblings are two or more individuals who share a parent in common. They are referred to as brothers or sisters depending on gender. When it comes to child development, sibling relationships can be incredibly important. Siblings represent a child’s first social network, and these early relationships provide a training ground for social learning and relationship building. Because of the intimate nature of these relationships, conflict is almost inevitable. Qualified family therapists and other mental health professionals can help individuals work through sibling issues and other family-related challenges.

Sleep Disorders Sleep-wake disorders are marked by disturbances in sleep patterns. They may impact physical, mental, and emotional health. External factors can cause sleep disorders. These may include anxiety, depression, trauma, or a life transition. If you have sleep issues, it is important to report any symptoms to your doctor.

Sleepwalking is a sleep disorder that causes people to become active—usually by walking—while still asleep. The disorder is also called somnambulism and is especially common in children.

Smoking Cessation is the process of quitting smoking. Because smoking causes both chemical and psychological dependency, strategies for smoking cessation typically aim to help alleviate physical symptoms and develop tactics to help control the desire to smoke in situations where one might typically smoke. Those who wish to quit smoking but find it difficult to do so may find it helpful to speak to a therapist.

Sobriety or being sober, can be defined as the state of not being intoxicated. In the fields of addiction and mental health treatment, sobriety typically refers to a person’s decision to maintain abstinence from substance use. Sobriety often, but not always, follows a period of problematic use or addiction.

Social Anxiety / Phobia is also known as social phobia. Simply put, it is fear of social situations. It is also described as fear of interacting with people other than close friends and family. Social anxiety can be persistent. It affects daily life for many people.

Social Norms are a broad set of prescriptions, both explicit and implicit, that dictate behavior in particular situations. They vary from culture to culture and often change over time. Norms can also change based on subculture and setting. For example, desirable behavior among a group of friends is not necessarily desirable behavior in the workplace.

Social Psychology is the study of an individual’s behavior in a social context. It is closely related to, though distinct from, sociology. While sociologists study group behavior and social norms, social psychologists study the interplay between group dynamics and individual behavior.

Social Status is a term used in social sciences such as psychology, anthropology, and sociology to indicate the level of respect and honor associated with a person’s position in society.

Social Work is a professional practice that involves helping people improve their individual and collective welfare by maximizing personal skills and community resources. It is grounded in the principles of human rights, social justice, and mutual responsibility. Social workers require an in-depth understanding of human behavior and development, as well as the functions of social, cultural, and economic institutions. Individuals, families, non-familial groups, organizations, and even entire communities may benefit from social work.

Socialization is the process of acquiring social skills, cultural norms, and societal customs. Although the process continues throughout life, socialization plays a significant role in psychological development during childhood. Children who are completely deprived of social contact in their early years may, in some cases, be unable to develop culturally accepted social skills as adults.

Sociology is a social science aimed at understanding the behavior of people in social groups.

Solution-Focused Brief Therapy (SFBT) places focus on a person’s present and future circumstances and goals rather than past experiences. In this goal-oriented therapy, the symptoms or issues bringing a person to therapy are typically not targeted. Instead, a qualified therapist encourages those in treatment to develop a vision of the future and offers support as they determine the skills, resources, and abilities needed to achieve that vision successfully.

Somatic Experiencing (SE™) was developed by Peter A. Levine, PhD to address the effects of trauma. Levine developed this approach after observing that prey animals, whose lives are routinely threatened in the wild, are able to recover readily by physically releasing the energy they accumulate during stressful events. Humans, on the other hand, often override these natural ways of regulating the nervous system with feelings of shame and pervasive thoughts, judgments, and fears. Somatic Experiencing aims to help people move past the place where they might be “stuck” in processing a traumatic event.

Somatic Psychotherapy, a holistic therapeutic approach, incorporates a person’s mind, body, spirit, and emotions in the healing process. Proponents of this type of therapy believe a person’s thoughts, attitudes, feelings, and beliefs can have an impact on physical functioning, while physical factors such as diet, exercise, and posture may positively or negatively affect a person’s mental and emotional state. Thus, those seeking treatment for any number of mental health concerns may incorporating somatic therapy into treatment to be beneficial.

Somatization occurs when psychological concerns are converted into physical symptoms. Though they have no underlying physical cause, somatic symptoms, such as pain or nausea, are very real and have not been invented by the person experiencing them.

Spirituality, a search for transcendent meaning or the belief in some sort of greater existence outside of humankind, can be linked to religion, but the practice of spirituality is generally considered to go beyond religion and link individuals with something larger, such as the universe itself. Both therapists and people seeking treatment may hesitate to include spirituality or religion in the practice of therapy, due to the potential of differing beliefs and the possible controversy of the topic. But research suggests a therapist’s inclusion of an individual’s spiritual beliefs may assist in therapy and in the process of healing.

Sport / Fitness Psychology is an approach that focuses on the intersection between sport science, medicine, and psychology. This therapeutic model expands on research, theory, and practices to improve performance in professional and amateur athletic settings. Sport psychology researchers work to understand how psychological factors can impact motor performance and how participation in physical activity affects human psychological development. Sports psychologists are also interested in understanding how social and psychological interventions affect the well-being of athletes, teams, coaches, parents, spectators, trainers, exercisers, and participants who are engaged in physical activities.

Spousal Abuse also referred to as domestic violence or intimate partner violence, is a behavioral cycle that involves emotional, physical, or sexual violence inflicted on an individual in a domestic context, such as cohabitation or marriage. Anyone can be a victim, regardless of race, gender, age, sexual orientation, or economic background. According to the United States Department of Justice, 1.3 million women and 835,000 men are victims of physical violence by an intimate partner annually.

Stage Fright is a kind of performance anxiety associated with performing in front of a large audience. Musicians, singers, people giving speeches, and anyone else who must perform in front of a group may experience stage fright.

Stalking is the act of repeatedly following, observing, or initiating contact with a person who has not consented to the behavior. Though some stalkers believe their intentions are innocent, their actions often intimidate victims. Stalking can be a serious crime. The legal ramifications can vary from fines to jail time, depending on the offense.

Standard of Care a term used in medical and mental health treatment, refers to the usual and customary practices within the field. The standard of care is designed to protect consumers of health services by setting a minimum standard for what is considered acceptable behavior by treatment providers.

Stelazine (trifluoperazine) belongs to a class of drugs called conventional or typical antipsychotics. It is a prescription medication used primarily in the management of symptoms associated with schizophrenia. Stelazine may also be used as a short-term treatment for people who experience anxiety that have not responded to other medications. While this drug has proven to be effective in the management of certain symptoms, it will not cure schizophrenia or anxiety issues. Typically people experiencing those conditions seek additional treatment options such as psychotherapy in conjunction with taking medication. Stelazine has been discontinued by its manufacturer and is no longer for sale in the United States as of 2004. It is available by its generic name only.

Stereotype is a set of generalizations—which are often unconscious—about a group of people. The stereotype is often applied to individual members. In direct forms of bigotry, bigots believe that all members of the group match the stereotype, while in indirect forms of discrimination, stereotypes subtly influence impressions of individual members of the group. Individual members of the group may be assessed as conforming to the stereotype even when they do not.

Stigma refers to a perceived disadvantage or mark of disgrace that is used to set an individual or specific group apart from other members of society.

Stimulants are a type of drug that alters activity within the central and peripheral nervous systems. Most stimulants have an effect on blood pressure, heart rate, and alertness. Some drugs within this category have immense therapeutic value, while some have no clinical application.

Stress is often defined as a bodily response to the demands of life. But there are also emotional and mental aspects of stress. It is experienced as thoughts and feelings as well as in the body. Another way to define stress could be as an internal and conditioned response to external pressures. Mental health professionals often help people reduce and manage their stress. They can also help people work through other mental health issues that have developed while coping with high levels of stress over a period of time.

Stuttering is a manner of talking where a person’s flow of speech is disrupted. Someone who stutters may repeat syllables or pause between words. When stuttering is common enough to interfere with normal speech, it is classified as a speech pathology.

A subculture is a smaller culture with a shared collection of beliefs, values, traditions, and rituals within a larger culture.

Substance Abuse Addiction, or dependence on a particular substance or activity, is one of the most complex areas of mental health. Addiction can often be difficult to treat, and there is a good deal of controversy surrounding the causes of addiction and the best approaches to treatment. Individuals who find themselves experiencing an addiction to drugs or alcohol often find the services of a mental health professional to be helpful in overcoming the addiction.

Suicide Suicidal ideation is a common medical term for thoughts about suicide. Thoughts may be fleeting in nature, or they may persist and resolve into a formulated plan. Many people who experience suicidal thoughts do not die by suicide, although they may exhibit suicidal behavior or make suicide attempts. People who find themselves experiencing suicidal thoughts or behaviors may find that they do so as a result of conditions such as depression, hopelessness, severe anxiety, insomnia, or panic attacks. Not all people who are diagnosed with these or other medical or mental health conditions will experience suicidal ideation, but some may. All suicidal ideation and behavior should be taken seriously, and those who have suicidal thoughts or know someone who is experiencing suicidal ideation should contact a crisis line as soon as possible.

Superego In Freudian psychology, the superego is the part of the personality that makes moral demands, that guides a person’s spiritual impulses, and that aims for perfection. It is one third of the psychic apparatus proposed by Sigmund Freud, that also contains the id, which controls basic drives and impulses, and the ego, which is the core of the rational personality that must balance the needs of the id and superego.

Survivor Guilt is a particular type of guilt that may develop in people who have survived a life-threatening situation. Individuals who believe it is unfair that they survived when others died and/or believe they did not do enough to save the lives of others may come to experience survivor guilt after trauma or a catastrophic event.

Sympathetic Nervous System sometimes abbreviated as SNS, is a component of the autonomic nervous system—the portion of the nervous system largely concerned with regulating automatic functions such as heart rate and digestion. Although commonly regarded as the portion of the nervous system that instigates the fight or flight response, the sympathetic nervous system also fulfills a constant role in regulating homeostasis—the maintenance of relatively consistent internal states.

Synapse is the point at which a neuron sends signals to another neuron, and consists of a tiny gap between the two neurons.

Systems Theory / Therapy also called systems science, is the multidisciplinary study of systems to investigate phenomena from a holistic approach. Systems, which can be natural or man-made and living or nonliving, are found in many aspects of human life. People who adhere to systems thinking, or the systemic perspective, believe it is impossible to truly understand a phenomenon by breaking it up into its basic components. They believe, rather, that a global perspective is necessary for comprehending the entire phenomenon.