The prion protein has two forms: the normal form (PrPc) and the infectious form (PrPSc). The normal form can be broken down by proteases, while the infectious form is resistant to proteases.

Prion Protein and its Role in Disease

Prion protein is a type of infective agent that is composed of protein. It is made up of proteins called PrP, which exist in two forms: a normal form (PrPC) and an abnormal form (PrPSc). The abnormal form is resistant to protease, which means it cannot be broken down in the body. This abnormal form can change adjacent normal PrPC into the abnormal form, which is how the infection spreads.

PrPC is a normal component of cell membranes and has an alpha-helical structure. However, in PrPSc, much of the alpha-helical structure is replaced by a beta-sheet structure. This change in structure causes PrPSc to aggregate into plaques in the extracellular space of the central nervous system, disrupting normal tissue structure.

Prions cause disease by this disruption of normal tissue structure, leading to neurological symptoms and ultimately death. Understanding the structure and behavior of prion proteins is crucial in developing treatments and preventative measures for prion diseases.

Personality Disorder Classification

A personality disorder is a persistent pattern of behavior and inner experience that deviates significantly from cultural expectations, is inflexible and pervasive, and causes distress of impairment. The DSM-5 and ICD-11 have different approaches to classifying personality disorders. DSM-5 divides them into 10 categories, grouped into clusters A, B, and C, while ICD-11 has a general category with six trait domains that can be added. To diagnose a personality disorder, the general diagnostic threshold must be met before determining the subtype(s) present. The criteria for diagnosis include inflexibility and pervasiveness of the pattern, onset in adolescence of early adulthood, stability over time, and significant distress of impairment. The disturbance must not be better explained by another mental disorder, substance misuse, of medical condition.

Course

Borderline and antisocial personality disorders tend to become less evident of remit with age, while others, particularly obsessive-compulsive and schizotypal, may persist.

Classification

The DSM-5 divides personality disorders into separate clusters A, B, and C, with additional groups for medical conditions and unspecified disorders. The ICD-11 dropped the separate categories and instead lists six trait domains that can be added to the general diagnosis.

Modes of Inheritance

Genetic disorders can be passed down from one generation to the next in various ways. There are four main modes of inheritance: autosomal dominant, autosomal recessive, X-linked (sex-linked), and multifactorial.

Autosomal Dominant Inheritance

Autosomal dominant inheritance occurs when one faulty gene causes a problem despite the presence of a normal one. This type of inheritance shows vertical transmission, meaning it is based on the appearance of the family pedigree. If only one parent is affected, there is a 50% chance of each child expressing the condition. Autosomal dominant conditions often show pleiotropy, where a single gene influences several characteristics.

Autosomal Recessive Inheritance

In autosomal recessive conditions, a person requires two faulty copies of a gene to manifest a disease. A person with one healthy and one faulty gene will generally not manifest a disease and is labelled a carrier. Autosomal recessive conditions demonstrate horizontal transmission.

X-linked (Sex-linked) Inheritance

In X-linked conditions, the problem gene lies on the X chromosome. This means that all males are affected. Like autosomal conditions, they can be dominant of recessive. Affected males are unable to pass the condition on to their sons. In X-linked recessive conditions, the inheritance pattern is characterised by transmission from affected males to male grandchildren via affected carrier daughters.

Multifactorial Inheritance

Multifactorial conditions result from the interaction between genes from both parents and the environment.

Extrapyramidal side-effects (EPSE’s) are a group of side effects that affect voluntary motor control, commonly seen in patients taking antipsychotic drugs. EPSE’s include dystonias, parkinsonism, akathisia, and tardive dyskinesia. They can be frightening and uncomfortable, leading to problems with non-compliance and can even be life-threatening in the case of laryngeal dystonia. EPSE’s are thought to be due to antagonism of dopaminergic D2 receptors in the basal ganglia. Symptoms generally occur within the first few days of treatment, with dystonias appearing quickly, within a few hours of administration of the first dose. Newer antipsychotics tend to produce less EPSE’s, with clozapine carrying the lowest risk and haloperidol carrying the highest risk. Akathisia is the most resistant EPSE to treat. EPSE’s can also occur when antipsychotics are discontinued (withdrawal dystonia).

The reason behind absent-mindedness is typically due to insufficient activation of the left inferior prefrontal and parahippocampal regions during the initial encoding process, resulting in shallow processing.

Memory: Encoding, Storage, Retrieval, and Failure

Memory is a complex process that involves encoding, storage, and retrieval of information. Encoding refers to how information is placed into memory, and it can be improved by organizing data using techniques such as chunking and mnemonics. Storage refers to keeping information in memory, which can be short-term of long-term. Retrieval refers to getting information back from memory when needed, and it can be affected by primacy and recency effects.

However, memory is not infallible, and there are seven ways in which it tends to fail. Transience refers to the decreasing accessibility of memory over time, while absent-mindedness is characterized by lapses of attention and forgetting to do things. Blocking is the temporary inaccessibility of stored information, while suggestibility involves the incorporation of misinformation into memory due to leading questions of deception.

Bias refers to retrospective distortions produced by current knowledge and beliefs, while persistence involves unwanted recollections that people cannot forget, such as the intrusive memories of post-traumatic stress disorder. Finally, misattribution refers to the attribution of memories to incorrect sources of believing that one has seen of heard something that they have not, such as in the case of deja vu of cryptomnesia.

Overall, memory is a complex and active process that can be affected by various factors, leading to failures in encoding, storage, retrieval, and attribution.

There are three morphologically distinct types of taste buds including; circumvallate, fungiform and foliate. Circumvallate are rounded structures arranged in a v on the back of the tongue. The posterior third travels to glossopharyngeal nerve.

Physiological tremors can be intensified by several drugs, while alcohol and benzodiazepines have a tendency to reduce tremors.

Types of Tremor

Essential Tremor

Otherwise known as benign essential tremor, this is the most common type of tremor. It is not associated with any underlying pathology. It usually begins in the 40’s, affects mainly the hands, and is slowly progressive. It tends to worsen with heightened emotion. It usually presents with unilateral upper limb involvement then progresses to both limbs.

Parkinsonian Tremor

This tremor is associated with Parkinson’s disease. It is classically described as ‘pill rolling’ due to the characteristic appearance of the fingers.

Cerebellar Tremor

Otherwise known as an intention tremor. This is a slow, coarse tremor which gets worse with purposeful movement. This is seen in lithium toxicity (note that the tremor seen as a side effect of long term lithium is fine and classed as physiological).

Psychogenic Tremor

Also known as a hysterical tremor. This type of tremor tends to appear and disappear suddenly and is hard to characterise due to its changeable nature. It tends to improve with distraction.

Physiologic Tremor

This is a very-low-amplitude fine tremor that is barely visible to the naked eye. It is present in every normal person while maintaining a posture of movement. It becomes enhanced and visible in many conditions such as anxiety, hyperthyroidism, alcohol withdrawal, and as drug induced side effects.

It is useful to have a basic idea about the frequencies of different types of tremor.

Type of Tremor Frequency

Intention 2-3Hz

Parkinsonian 5Hz

Essential 7Hz

Physiological 10Hz

Psychogenic variable

Psychiatric Terminology

Double orientation refers to the separation of belief from feeling and behavior, which is commonly observed in chronic schizophrenics. This condition is characterized by a person holding a grandiose delusion, such as believing they are the King of England, while still living a normal life in a council house and attending a day center. Loosening of associations is a type of thought disorder, while an overvalued idea is a preoccupying belief that is arrived at through normal mental processes. Partial delusion is a delusion that is becoming less fixed of is on its way to becoming a full delusion. Vorbeireden, also known as talking past the point, is another term used in psychiatric terminology.

Goffman’s work focused extensively on stigma, while Cerletti is known for his contributions to the development of electroconvulsive therapy (ECT), and Moniz is associated with the development of frontal lobotomy.

History of major works in psychiatry
Michel Foucault – Madness and civilization
Sigmund Freud – The interpretation of dreams, Beyond the Pleasure Principle, The Psychopathology of everyday life
Thomas Szasz – The myth of mental illness
Erving Goffman – Asylums, The Presentation of Self in Everyday Life
Ronald Laing – The divided self
Emile Durkheim – Le suicide. Durkheim proposed social causes for suicide. Until his work was published, suicide had been thought of as an individual act only.
Tom Main – The Ailment
Jerome Frank – Persuasion and Healing
George Brown and Tirril Harris – Social origins of depression

This question is a common one, but it is worded in various ways each time.

Neuroimaging Findings in Obsessive-Compulsive Disorder (OCD)

Obsessive-compulsive disorder (OCD) is a mental disorder characterized by intrusive thoughts (obsessions) and repetitive behaviors (compulsions). Neuroimaging studies have been conducted to investigate the underlying neural mechanisms of OCD. Two commonly used techniques are 18 Fluorodeoxyglucose PET (FDG-PET) and Technetium-99m (99mTc)-hexamethylpropyleneamine-oxime SPECT (HMPAO-SPECT).

Studies using FDG-PET have reported increased glucose metabolism in several brain regions among OCD patients, including the orbitofrontal cortex (OFC), caudate, thalamus, prefrontal cortex, and anterior cingulate. These regions are involved in cognitive and emotional processing, decision-making, and motor control. The increased activity in these regions may contribute to the symptoms of OCD, such as repetitive behaviors and difficulty controlling intrusive thoughts.

On the other hand, studies using HMPAO-SPECT have found both increased and decreased blood flow to various brain regions in OCD patients compared to normal controls. These regions include the OFC, caudate, various areas of the cortex, and thalamus. The inconsistent findings may be due to differences in the severity and subtype of OCD, as well as the specific task of stimulus used in the imaging studies.

Overall, neuroimaging studies have provided valuable insights into the neural mechanisms of OCD. However, further research is needed to better understand the complex interactions between different brain regions and how they contribute to the development and maintenance of OCD symptoms.

Types of Tremor

Essential Tremor

Otherwise known as benign essential tremor, this is the most common type of tremor. It is not associated with any underlying pathology. It usually begins in the 40’s, affects mainly the hands, and is slowly progressive. It tends to worsen with heightened emotion. It usually presents with unilateral upper limb involvement then progresses to both limbs.

Parkinsonian Tremor

This tremor is associated with Parkinson’s disease. It is classically described as ‘pill rolling’ due to the characteristic appearance of the fingers.

Cerebellar Tremor

Otherwise known as an intention tremor. This is a slow, coarse tremor which gets worse with purposeful movement. This is seen in lithium toxicity (note that the tremor seen as a side effect of long term lithium is fine and classed as physiological).

Psychogenic Tremor

Also known as a hysterical tremor. This type of tremor tends to appear and disappear suddenly and is hard to characterise due to its changeable nature. It tends to improve with distraction.

Physiologic Tremor

This is a very-low-amplitude fine tremor that is barely visible to the naked eye. It is present in every normal person while maintaining a posture of movement. It becomes enhanced and visible in many conditions such as anxiety, hyperthyroidism, alcohol withdrawal, and as drug induced side effects.

It is useful to have a basic idea about the frequencies of different types of tremor.

Type of Tremor Frequency

Intention 2-3Hz

Parkinsonian 5Hz

Essential 7Hz

Physiological 10Hz

Psychogenic variable

Dysarthria is a speech disorder that affects the volume, rate, tone, of quality of spoken language. There are different types of dysarthria, each with its own set of features, associated conditions, and localisation. The types of dysarthria include spastic, flaccid, hypokinetic, hyperkinetic, and ataxic.

Spastic dysarthria is characterised by explosive and forceful speech at a slow rate and is associated with conditions such as pseudobulbar palsy and spastic hemiplegia.

Flaccid dysarthria, on the other hand, is characterised by a breathy, nasal voice and imprecise consonants and is associated with conditions such as myasthenia gravis.

Hypokinetic dysarthria is characterised by slow, quiet speech with a tremor and is associated with conditions such as Parkinson’s disease.

Hyperkinetic dysarthria is characterised by a variable rate, inappropriate stoppages, and a strained quality and is associated with conditions such as Huntington’s disease, Sydenham’s chorea, and tardive dyskinesia.

Finally, ataxic dysarthria is characterised by rapid, monopitched, and slurred speech and is associated with conditions such as Friedreich’s ataxia and alcohol abuse. The localisation of each type of dysarthria varies, with spastic and flaccid dysarthria affecting the upper and lower motor neurons, respectively, and hypokinetic, hyperkinetic, and ataxic dysarthria affecting the extrapyramidal and cerebellar regions of the brain.

Risk Factors for Delirium

Delirium is a common condition that affects many elderly individuals. There are several risk factors that can increase the likelihood of developing delirium. These risk factors include age, cognitive impairment, severe medical illness, previous history of delirium of neurological disease, psychoactive drug use, polypharmacy, and anticholinergic drug use.

Medications are the most common reversible cause of delirium and dementia in the elderly. Certain classes of drugs, such as opioids, benzodiazepines, and anticholinergics, are strongly associated with the development of drug-induced dementia. Long-acting benzodiazepines are more troublesome than shorter-acting ones. Opioids are associated with an approximately 2-fold increased risk of delirium in medical and surgical patients. Pethidine, a member of the opioid class, appears to have a higher risk of delirium compared with other opioids due to its accumulation in individuals with impaired renal function and conversion to a metabolite with anticholinergic properties.

Overall, it is important to be aware of these risk factors and to carefully monitor medication use in elderly individuals to prevent the development of delirium.

HPA Axis Dysfunction in Mood Disorders

The HPA axis, which includes regulatory neural inputs and a feedback loop involving the hypothalamus, pituitary, and adrenal glands, plays a central role in the stress response. Excessive secretion of cortisol, a glucocorticoid hormone, can lead to disruptions in cellular functioning and widespread physiologic dysfunction. Dysregulation of the HPA axis is implicated in mood disorders such as depression and bipolar affective disorder.

In depressed patients, cortisol levels often do not decrease as expected in response to the administration of dexamethasone, a synthetic corticosteroid. This abnormality in the dexamethasone suppression test is thought to be linked to genetic of acquired defects of glucocorticoid receptors. Tricyclic antidepressants have been shown to increase expression of glucocorticoid receptors, whereas this is not the case for SSRIs.

Early adverse experiences can produce long standing changes in HPA axis regulation, indicating a possible neurobiological mechanism whereby childhood trauma could be translated into increased vulnerability to mood disorder. In major depression, there is hypersecretion of cortisol, corticotropin-releasing factor (CRF), and ACTH, and associated adrenocortical enlargement. HPA abnormalities have also been found in other psychiatric disorders including Alzheimer’s and PTSD.

In bipolar disorder, dysregulation of ACTH and cortisol response after CRH stimulation have been reported. Abnormal DST results are found more often during depressive episodes in the course of bipolar disorder than in unipolar disorder. Reduced pituitary volume secondary to LHPA stimulation, resulting in pituitary hypoactivity, has been observed in bipolar patients.

Overall, HPA axis dysfunction is implicated in mood disorders, and understanding the underlying mechanisms may lead to new opportunities for treatments.

The EEG findings for Huntington’s disease typically show a widespread decrease in activity with low amplitude theta (θ) and delta (δ) waves. In contrast, CJD is characterized by bilateral, synchronous generalised irregular spike wave complexes occurring at a rate of 1-2/second, often accompanied by myoclonic jerks. Hepatic encephalopathy is associated with widespread slowing and triphasic waves, while herpes simplex encephalitis is linked to repetitive episodic discharges and temporal lobe focal slow waves. HIV typically demonstrates diffuse slowing on EEG.

The Cerebral Cortex and Neocortex

The cerebral cortex is the outermost layer of the cerebral hemispheres and is composed of three parts: the archicortex, paleocortex, and neocortex. The neocortex accounts for 90% of the cortex and is involved in higher functions such as thought and language. It is divided into 6-7 layers, with two main cell types: pyramidal cells and nonpyramidal cells. The surface of the neocortex is divided into separate areas, each given a number by Brodmann (e.g. Brodmann’s area 17 is the primary visual cortex). The surface is folded to increase surface area, with grooves called sulci and ridges called gyri. The neocortex is responsible for higher cognitive functions and is essential for human consciousness.

ICD-10’s Anankastic personality disorder is the same as DSM V obsessive-compulsive personality disorder, while inadequate and passive aggressive personality disorders are not recognized in either classification system. Additionally, DSM V includes narcissistic personality disorder as a distinct category of personality disorder.

Autism and Genetics

Research has shown that there is a strong genetic component to autism. In fact, siblings of individuals with autism are significantly more likely to develop the disorder than someone in the general population. Twin studies have also demonstrated the high heritability of autism, but have also highlighted the genetic complexity of the disorder. Monozygotic twins have a concordance rate of 60-90%, while dizygotic twins have a concordance rate closer to 30%. Despite this, the molecular genetics of autism is still not well understood. Copy number variations (CNVs) have been implicated, along with a number of candidate genes. Further research is needed to fully understand the genetic basis of autism.

Simultagnosia is a condition where an individual is unable to focus on more than one aspect of a complex scene at a time. This condition, along with optic ataxia and oculomotor apraxia, is part of Balint’s syndrome.

Gerstmann syndrome is characterized by four symptoms: dysgraphia/agraphia, dyscalculia/acalculia, finger agnosia, and left-right disorientation. This syndrome is linked to a lesion in the dominant parietal lobe, specifically the left side of the angular and supramarginal gyri. It is rare for an individual to present with all four symptoms of the tetrad.

Located in the brain stem is a series of purely sensory nuclei known as tractus solitaries. Inputs of the nucleus tractus solitaries include:
Taste information from the facial nerve (anterior 2/3 of the tongue), glossopharyngeal nerve (posterior 1/3) and vagus nerve (small area on the epiglottis).
Sensory information from the ear (auricular branch of the vagus nerve).
Chemoreceptors and mechanoreceptors of the general visceral afferent pathway (GVA) in the carotid body via glossopharyngeal nerve, aortic bodies, and the sinoatrial node, via the vagus nerve.
Chemically and mechanically sensitive neurons of the general visceral afferent pathway (GVA) with endings located in the heart, lungs, airways, gastrointestinal system, pharynx, and liver via the glossopharyngeal and vagus nerves.

If Peter had reached the stage of post-conventional morality, he would have evaluated whether purchasing sports equipment was a cause that aligned with his personal values and beliefs, rather than simply fulfilling a duty because his class was participating in it.

Secondary prevention aims to decrease the prevalence of a disorder by targeting individuals in the early stages of the disorder, with the goal of reducing its severity and duration and preventing it from becoming chronic. Primary prevention, on the other hand, aims to decrease the incidence of a disorder by targeting individuals who are at risk of developing the disorder but do not yet have it. Selected prevention is a type of primary prevention that focuses on individuals who are at an increased risk of developing the disorder due to factors such as family history. Tertiary prevention is aimed at individuals who already have the disorder, with the goal of reducing the associated disability. Universal prevention is a type of primary prevention that targets the entire population.

It is important to understand and memorize the distinction between functional and reflex hallucinations. Functional hallucinations involve the same sensory modality, while reflex hallucinations involve a different sensory modality. It is crucial to differentiate between the two.

Altered Perceptual Experiences

Disorders of perception can be categorized into sensory distortions and sensory deceptions. Sensory distortions involve changes in the intensity, spatial form, of quality of a perception. Examples include hyperaesthesia, hyperacusis, and micropsia. Sensory deceptions, on the other hand, involve new perceptions that are not based on any external stimulus. These include illusions and hallucinations.

Illusions are altered perceptions of a stimulus, while hallucinations are perceptions in the absence of a stimulus. Completion illusions, affect illusions, and pareidolic illusions are examples of illusions. Auditory, visual, gustatory, olfactory, and tactile hallucinations are different types of hallucinations. Pseudohallucinations are involuntary and vivid sensory experiences that are interpreted in a non-morbid way. They are different from true hallucinations in that the individual is able to recognize that the experience is an internally generated event.

Understanding the different types of altered perceptual experiences is important in the diagnosis and treatment of various mental health conditions.

α nerve fibers are characterized by being highly myelinated, which confers them with fast conduction properties. They innervate extrafusal skeletal muscle fibers, and their conduction velocity is between 80-120 m/s.

Glial Cells: The Support System of the Central Nervous System

The central nervous system is composed of two basic cell types: neurons and glial cells. Glial cells, also known as support cells, play a crucial role in maintaining the health and function of neurons. There are several types of glial cells, including macroglia (astrocytes and oligodendrocytes), ependymal cells, and microglia.

Astrocytes are the most abundant type of glial cell and have numerous functions, such as providing structural support, repairing nervous tissue, nourishing neurons, contributing to the blood-brain barrier, and regulating neurotransmission and blood flow. There are two main types of astrocytes: protoplasmic and fibrous.

Oligodendrocytes are responsible for the formation of myelin sheaths, which insulate and protect axons, allowing for faster and more efficient transmission of nerve impulses.

Ependymal cells line the ventricular system and are involved in the circulation of cerebrospinal fluid (CSF) and fluid homeostasis in the brain. Specialized ependymal cells called choroid plexus cells produce CSF.

Microglia are the immune cells of the CNS and play a crucial role in protecting the brain from infection and injury. They also contribute to the maintenance of neuronal health and function.

In summary, glial cells are essential for the proper functioning of the central nervous system. They provide structural support, nourishment, insulation, and immune defense to neurons, ensuring the health and well-being of the brain and spinal cord.

Redintegration pertains to the recollection of information from long term memory triggered by a cue, like a scent of noise. Recall entails actively searching memory stores for information. Recognition refers to the ability to identify an answer to a question from a list of options, without spontaneously recalling it. Reconstructive memory is the process of transferring information from one person to another. Relearning involves learning something again that was previously learned and forgotten, with faster learning occurring on subsequent attempts.

The three primary cell layers in embryonic development are the ectoderm, endoderm, and mesoderm. The ectoderm is responsible for the development of the nervous system, skin, and tooth enamel. The endoderm differentiates into the epithelial lining of the gastrointestinal, respiratory, and renal tracts, while the mesoderm develops into muscle, blood, and connective tissues. Within the ectodermal layer, a neural plate thickens and folds to form the neural tube, which ultimately gives rise to the brain and spinal cord.

Frontotemporal Lobar Degeneration (FTLD) is a pathological term that refers to a group of neurodegenerative disorders that affect the frontal and temporal lobes of the brain. FTLD is classified into several subtypes based on the main protein component of neuronal and glial abnormal inclusions and their distribution. The three main proteins associated with FTLD are Tau, TDP-43, and FUS. Each FTD clinical phenotype has been associated with different proportions of these proteins. Macroscopic changes in FTLD include atrophy of the frontal and temporal lobes, with focal gyral atrophy that resembles knives. Microscopic changes in FTLD-Tau include neuronal and glial tau aggregation, with further sub-classification based on the existence of different isoforms of tau protein. FTLD-TDP is characterized by cytoplasmic inclusions of TDP-43 in neurons, while FTLD-FUS is characterized by cytoplasmic inclusions of FUS.

Lithium – Pharmacology

Pharmacokinetics:
Lithium salts are rapidly absorbed following oral administration and are almost exclusively excreted by the kidneys unchanged. Blood samples for lithium should be taken 12 hours post-dose.

Ebstein’s:
Ebstein’s anomaly is a congenital malformation consisting of a prolapse of the tricuspid valve into the right ventricle. It occurs in 1:20,000 of the general population. Initial data suggested it was more common in those using lithium but this had not held to be true.

Contraindications:
Addison’s disease, Brugada syndrome, cardiac disease associated with rhythm disorders, clinically significant renal impairment, untreated of untreatable hypothyroidism, low sodium levels.

Side-effects:
Common side effects include nausea, tremor, polyuria/polydipsia, rash/dermatitis, blurred vision, dizziness, decreased appetite, drowsiness, metallic taste, and diarrhea. Side-effects are often dose-related.

Long-term use is associated with hypothyroidism, hyperthyroidism, hypercalcemia/hyperparathyroidism, irreversible nephrogenic diabetes insipidus, and reduced GFR.

Lithium-induced diabetes insipidus:
Treatment options include stopping lithium (if feasible), keeping levels within 0.4-0.8 mmol/L, once-daily dose of the drug taken at bedtime, amiloride, thiazide diuretics, indomethacin, and desmopressin.

Toxicity:
Lithium salts have a narrow therapeutic/toxic ratio. Risk factors for lithium toxicity include drugs altering renal function, decreased circulating volume, infections, fever, decreased oral intake of water, renal insufficiency, and nephrogenic diabetes insipidus. Features of lithium toxicity include GI symptoms and neuro symptoms.

Pre-prescribing:
Before prescribing lithium, renal function, cardiac function, thyroid function, FBC, and BMI should be checked. Women of childbearing age should be advised regarding contraception, and information about toxicity should be provided.

Monitoring:
Lithium blood levels should be checked weekly until stable, and then every 3-6 months once stable. Thyroid and renal function should be checked every 6 months. Patients should be issued with an information booklet, alert card, and record book.

The Positive and Negative Syndrome Scale (PANSS) is a tool used to measure the severity of symptoms in patients with schizophrenia. The scale is divided into three categories: positive symptoms, negative symptoms, and general psychopathology symptoms. Each category has several items that are scored on a seven-point severity scale. The positive symptoms include delusions, hallucinations, and hyperactivity, while the negative symptoms include blunted affect and lack of spontaneity. The general psychopathology symptoms include anxiety, depression, and poor impulse control. The PANSS is a valuable tool for clinicians to assess the severity of symptoms in patients with schizophrenia and to monitor their progress over time.