Clinical trialClinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietary choices, dietary supplements, and medical devices) and known interventions that warrant further study and comparison. Clinical trials generate data on dosage, safety and efficacy. They are conducted only after they have received health authority/ethics committee approval in the country where approval of the therapy is sought.
OpioidOpioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use disorder, reversing opioid overdose, and suppressing cough. Extremely potent opioids such as carfentanil are approved only for veterinary use. Opioids are also frequently used non-medically for their euphoric effects or to prevent withdrawal.
Blinded experimentIn a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expectations, observer's effect on the participants, observer bias, confirmation bias, and other sources. A blind can be imposed on any participant of an experiment, including subjects, researchers, technicians, data analysts, and evaluators.
Pain managementPain management is an aspect of medicine and health care involving relief of pain (pain relief, analgesia, pain control) in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professionals provide some pain control in the normal course of their practice, and for the more complex instances of pain, they also call on additional help from a specific medical specialty devoted to pain, which is called pain medicine.
Parkinson's diseaseParkinson's disease (PD), or simply Parkinson's, is a chronic degenerative disorder of the central nervous system that affects both the motor system and non-motor systems. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms become more common. Early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking. Problems may also arise with cognition, behaviour, sleep, and sensory systems. Parkinson's disease dementia becomes common in advanced stages of the disease.
Depression (mood)Depression is a mental state of low mood and aversion to activity. It affects more than 280 million people of all ages (about 3.5% of the global population). Depression affects a person's thoughts, behavior, feelings, and sense of well-being. Depressed people often experience loss of motivation or interest in, or reduced pleasure or joy from, experiences that would normally bring them pleasure or joy.
Randomized controlled trialA randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical techniques, medical devices, diagnostic procedures or other medical treatments. Participants who enroll in RCTs differ from one another in known and unknown ways that can influence study outcomes, and yet cannot be directly controlled.
Adverse effectAn adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term complication is similar to adverse effect, but the latter is typically used in pharmacological contexts, or when the negative effect is expected or common. If the negative effect results from an unsuitable or incorrect dosage or procedure, this is called a medical error and not an adverse effect.
Orbitofrontal cortexThe orbitofrontal cortex (OFC) is a prefrontal cortex region in the frontal lobes of the brain which is involved in the cognitive process of decision-making. In non-human primates it consists of the association cortex areas Brodmann area 11, 12 and 13; in humans it consists of Brodmann area 10, 11 and 47. The OFC is functionally related to the ventromedial prefrontal cortex. Therefore, the region is distinguished due to the distinct neural connections and the distinct functions it performs.
PainPain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage." Pain motivates organisms to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future.
Periaqueductal grayThe periaqueductal gray (PAG, also known as the central gray) is a brain region that plays a critical role in autonomic function, motivated behavior and behavioural responses to threatening stimuli. PAG is also the primary control center for descending pain modulation. It has enkephalin-producing cells that suppress pain. The periaqueductal gray is the gray matter located around the cerebral aqueduct within the tegmentum of the midbrain. It projects to the nucleus raphe magnus, and also contains descending autonomic tracts.
LiverThe liver is a major metabolic organ only found in vertebrate animals, which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the right upper quadrant of the abdomen, below the diaphragm and mostly shielded by the lower right rib cage. Its other metabolic roles include carbohydrate metabolism, the production of hormones, conversion and storage of nutrients such as glucose and glycogen, and the decomposition of red blood cells.
Classical conditioningClassical conditioning (also respondent conditioning and Pavlovian conditioning) is a behavioral procedure in which a biologically potent physiological stimulus (e.g. food) is paired with a neutral stimulus (e.g. the sound of a musical triangle). The term classical conditioning refers to the process of an automatic, conditioned response that is paired with a specific stimulus. The Russian physiologist Ivan Pavlov studied classical conditioning with detailed experiments with dogs, and published the experimental results in 1897.
NauseaNausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 definitions of nausea were proposed in a 2011 book on the topic. Nausea is a non-specific symptom, which means that it has many possible causes.
MotivationMotivation is the reason for which humans and other animals initiate, continue, or terminate a behavior at a given time. Motivational states are commonly understood as forces acting within the agent that create a disposition to engage in goal-directed behavior. It is often held that different mental states compete with each other and that only the strongest state determines behavior. This means that we can be motivated to do something without actually doing it. The paradigmatic mental state providing motivation is desire.
Nucleus accumbensThe nucleus accumbens (NAc or NAcc; also known as the accumbens nucleus, or formerly as the nucleus accumbens septi, Latin for "nucleus adjacent to the septum") is a region in the basal forebrain rostral to the preoptic area of the hypothalamus. The nucleus accumbens and the olfactory tubercle collectively form the ventral striatum. The ventral striatum and dorsal striatum collectively form the striatum, which is the main component of the basal ganglia.
EfficacyEfficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as effectiveness, and it has often been used synonymously, although in pharmacology a distinction is now often made between efficacy and effectiveness. The word efficacy is used in pharmacology and medicine to refer both to the maximum response achievable from a pharmaceutical drug in research settings, and to the capacity for sufficient therapeutic effect or beneficial change in clinical settings.
NoceboA nocebo effect is said to occur when negative expectations of the patient regarding a treatment cause the treatment to have a more negative effect than it otherwise would have. For example, when a patient anticipates a side effect of a medication, they can experience that effect even if the "medication" is actually an inert substance. The complementary concept, the placebo effect, is said to occur when positive expectations improve an outcome.
AnticonvulsantAnticonvulsants (also known as antiepileptic drugs or antiseizure drugs) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder and borderline personality disorder, since many seem to act as mood stabilizers, and for the treatment of neuropathic pain. Anticonvulsants suppress the excessive rapid firing of neurons during seizures. Anticonvulsants also prevent the spread of the seizure within the brain.
Informed consentInformed consent is a principle in medical ethics and medical law and media studies, that a patient must have sufficient information and understanding before making decisions about their medical care. Pertinent information may include risks and benefits of treatments, alternative treatments, the patient's role in treatment, and their right to refuse treatment. In most systems, healthcare providers have a legal and ethical responsibility to ensure that a patient's consent is informed.
