schizophrenia elm terms and definitions

AKT1

A gene encoding a serine/threonine kinase involved in intracellular signalling pathways that regulate cell survival and synaptic plasticity; variants in AKT1 are associated with increased risk of psychosis, particularly in the context of cannabis use.

Antipsychotic

A class of drugs used to treat psychotic symptoms.

Approved Mental Health Professional (AMHP)

A specially trained professional authorised under the Mental Health Act to coordinate assessments and make applications for compulsory detention.

Associative striatum

A functional subdivision of the striatum involved in cognitive processing and goal-directed behaviour, often implicated in psychosis-related dopamine dysregulation.

Catatonia

Psychomotor symptoms characterised by abnormal movement, posture, or behaviour, ranging from stupor and immobility to excessive, purposeless activity.

Cognitive symptoms

Deficits in mental processes such as attention, memory, executive function, and processing speed that commonly occur in schizophrenia and contribute substantially to functional impairment.

Co-morbid

Describes the presence of one or more additional disorders occurring alongside a primary condition.

Cortical-basal ganglia loop

A series of interconnected neural circuits linking the cortex, basal ganglia, thalamus, and back to cortex, involved in motor, cognitive, and emotional regulation.

Delusion

A fixed, false belief that is held with strong conviction despite clear evidence to the contrary and is not explained by cultural or religious background.

Dirty drug

An informal term for a drug that acts at multiple receptor types, often producing both therapeutic effects and a wide range of side effects.

DISC1

(Disrupted In schizophrenia). A gene originally identified in a Scottish family with a high prevalence of psychiatric illness; it plays a role in neurodevelopment and synaptic function and is linked to schizophrenia risk.

Dopamine hypothesis version 1

The original hypothesis proposing that schizophrenia results from global hyperactivity of dopamine transmission, particularly due to excessive dopamine release.

Dopamine hypothesis version 2

A refinement suggesting that schizophrenia involves excess dopaminergic activity in the mesolimbic pathway and underactivity in cortical areas.

Dopamine hypothesis version 3

A contemporary model proposing that dopamine dysregulation is a downstream consequence of more fundamental abnormalities in glutamatergic, GABAergic and neurodevelopmental processes.

Dutch Hunger Winter Famine

A period of severe famine in the Netherlands during 1944–1945; prenatal exposure is associated with increased risk of schizophrenia in later life. It was caused by the disruption of food supplies in the wake of the Allied landings in Europe, and resulted in between 20000 and 35000 deaths.

Dysbindin

A protein encoded by the DTNBP1 gene, involved in synaptic transmission and vesicle trafficking; reduced expression has been linked to schizophrenia.

Extrapyramidal side effects (EPS)

Drug-induced movement disorders, including parkinsonism, akathisia, dystonia, and tardive dyskinesia, commonly associated with dopamine D2 receptor blockade.

Final common pathway

A concept describing how diverse genetic and environmental risk factors converge on shared neural mechanisms that ultimately produce psychotic symptoms.

Galactorrhea

Inappropriate milk secretion from the breast, often caused by antipsychotic-induced elevation of prolactin levels.

GWAS

Genome-wide association study; a research approach that scans the genome to identify genetic variants associated with a particular disorder.

Hallucination

A perception-like experience occurring in the absence of an external stimulus, most commonly auditory in schizophrenia but visual, olfactory and tactile hallucinations can also occur.

Mental Health Act 1983

The primary legislation in England and Wales governing the compulsory assessment and treatment of individuals with mental disorders.

Mesocortical pathway

A dopamine pathway projecting from the ventral tegmental area to the prefrontal cortex, implicated in cognitive and negative symptoms when underactive.

Mesolimbic pathway

A dopamine pathway projecting from the ventral tegmental area to limbic regions such as the nucleus accumbens.

Metabolic syndrome

A cluster of metabolic abnormalities, including weight gain, dyslipidaemia, hypertension, and insulin resistance, often associated with second-generation antipsychotics.

Negative symptoms

Reductions or losses of normal functions, including blunted affect, avolition, anhedonia, alogia, and social withdrawal.

Neuregulin 1

A gene involved in neural development, synaptic plasticity, and myelination; genetic variation is associated with schizophrenia risk.

Nigrostriatal pathway

A dopamine pathway projecting from the substantia nigra to the dorsal striatum, critical for motor control and involved in extrapyramidal side effects. Also involved in salience processing and emotional regulation.

Positive symptoms

Additions to normal experience, such as hallucinations, delusions, and disorganised thought or behaviour.

Prodromal/prodrome

The early phase preceding the onset of psychosis, characterised by subtle changes in mood, cognition, and behaviour.

Psychosis

A clinical syndrome involving impaired reality perception, typically manifesting as hallucinations, delusions, or thought disorder.

Salience

The process by which stimuli are assigned importance; in psychosis, aberrant salience attribution leads to inappropriate significance being attached to neutral events.

Schizoaffective disorder (bipolar/depressive types)

A disorder characterised by symptoms of schizophrenia occurring alongside mood episodes, classified according to whether manic or depressive features predominate.

Schizophrenia

A chronic psychiatric disorder characterised by disturbances in perception, thought, emotion, and behaviour, with positive, negative, and cognitive symptoms.

Section 135

A provision of the Mental Health Act allowing police to enter private premises to remove a person for mental health assessment under a warrant.

Section 136

A provision allowing police to detain a person appearing mentally unwell in a public place and take them to a place of safety for assessment.

Section 2

A section of the Mental Health Act permitting compulsory detention for assessment for up to 28 days.

Section 3

A section of the Mental Health Act permitting compulsory detention for treatment for up to six months, renewable.

Section 4

An emergency provision allowing short-term detention for assessment when only one medical recommendation is available.

Section 5

A holding power allowing short-term detention of voluntary inpatients to prevent them leaving hospital while an assessment is arranged.

Sectioning

Informal term for the process of compulsory detention under the Mental Health Act.

Soft signs

Subtle neurological abnormalities, such as impaired coordination or sensory integration, often observed in schizophrenia.

Tardive dyskinesia

A potentially irreversible movement disorder characterised by repetitive, involuntary movements, usually developing after long-term antipsychotic use.

Toxoplasma gondii

A parasitic organism whose latent infection has been associated with increased risk of schizophrenia.

Tuberoinfundibular pathway

A dopamine pathway projecting from the hypothalamus to the pituitary gland, involved in regulation of prolactin secretion.