Schizophrenia Spectrum and Psychotic Disorders

Comprehensive practice flashcards defining core vocabulary, diagnostic criteria, clinical phases, symptom types, and aetiological concepts for the schizophrenia spectrum and psychotic disorders based on lecture notes.

Psychosis

A general umbrella term describing a split from or loss of contact with reality, characterized by an inability to discern what is real versus not real, or internal self-generated experiences versus external other-generated experiences. In the DSM, it is restricted to the presence of active symptoms like delusions or hallucinations.

Lifetime Prevalence of Schizophrenia

Approximately $1\%$ of the population across North America and Europe.

Prodromal Phase

The subclinical initial phase of schizophrenia marked by a noticeable deterioration in functioning (often described as a "personality change"), featuring odd, peculiar, or bizarre behaviour, unusual perceptual experiences, tension, restlessness, angry outbursts, and social isolation.

Active Phase

The acute phase of schizophrenia during which diagnostic criteria are fully met, requiring active psychotic symptoms (such as delusions, hallucinations, or disorganised speech) to be present for a significant portion of time during a 1-month period (or less if successfully treated).

Residual Phase

The phase following an active episode where active psychotic symptoms have subsided or reduced in severity but still impair functioning, and negative symptoms typically persist.

Positive Symptoms

Symptoms of schizophrenia that reflect an excess or distortion of normal psychological functioning, including delusions, hallucinations, and disorganised speech or behaviour.

Negative Symptoms

Symptoms of schizophrenia characterized by a deficiency or absence of normal psychological functioning, such as diminished emotional expression (blunted affect), avolition, and alogia.

Psychotic Features (Criterion A1 & A2)

The hallmark active-phase features of schizophrenia and related psychotic disorders, specifically comprising delusions (A1) and hallucinations (A2).

DSM-5 Symptom Duration Criterion for Schizophrenia

Continuous signs of the disturbance must persist for at least 6 months, which must include at least 1 month of active-phase symptoms (or less if successfully treated) across prodromal, active, and residual phases.

Key Indicator Symptoms (DSM-5 Criterion A)

The three core symptoms of which at least one must be present to establish a diagnosis of schizophrenia: delusions, hallucinations, or disorganised speech.

Delusion

An idiosyncratic, clearly false ("preposterous"), and unshakeable belief based on incorrect inferences about external reality that is firmly maintained despite conflicting evidence or demonstrated reality, and is not shared by family or cultural peers as an article of faith.

Hallucination

A compelling sensory perception occurring in the absence of an external stimulus that is interpreted as real, differing from an illusion which involves the misinterpretation of an actual external stimulus.

Delusion of Persecution

A delusional conviction that one is being attacked, harassed, cheated, spied upon, or conspired against by others or external forces.

Delusion of Grandeur

A delusional theme involving an exaggerated, highly inflated sense of personal self-worth, power, specialized knowledge, personal identity, or unique connections with a deity or famous person.

Delusion of Being Controlled

A delusional belief that one's feelings, impulses, thoughts, or physical actions are not under one's own volition, but are manipulated or directed by outside forces or individuals.

Hypnogogic and Hypnopompic Hallucinations

Transient sensory perceptions occurring while falling asleep (hypnogogic) or waking up (hypnopompic) that represent normal physiological phenomena and do not qualify as psychotic symptoms.

Formal Thought Disorder

A disturbance in the organization and flow of thought, clinically inferred from disorganised or disordered speech patterns that impair verbal communication and cannot be explained by low formal education or primary linguistic impairments.

Tangentiality

A type of disorganised speech in which a person gives rambling answers that are completely unrelated or obliquely related to the questions asked.

Derailment (Loose Associations)

A form of disorganised speech where a person's train of thought constantly breaks apart, jumping unpredictably from one topic to another unrelated thought.

Word Salad

Severe speech disorganization characterized by highly fragmented words and phrases that fail to follow linguistic grammatical conventions, rendering communication incomprehensible.

Alogia

An impoverishment in thinking reflected in speech that conveys very little information due to being repetitive, over-concrete, or over-abstract ("poverty of content") or speech characterized by extremely brief, laconic replies ("poverty of speech").

Avolition

A core negative symptom defined in DSM-5 as a marked reduction in the drive, energy, or initiative to initiate and pursue goal-directed activities.

Catatonia

A state of profound behavioural abnormality and altered reactivity to the environment, manifesting as motoric immobility (stupor or catalepsy), unresponsiveness, awkward postures, or purposeless, repetitive motoric excesses (such as pacing or hand wringing).

Schizophrenia Subtype Removal in DSM-5

The elimination of classic clinical subtypes (paranoid, catatonic, hebephrenic/disorganized) in DSM-5 due to their poor empirical reliability (e.g., catatonic $\kappa = 0.39$, hebephrenic $\kappa = 0.43$) and low diagnostic stability over time.

Attenuated Psychosis Syndrome (APS)

A condition proposed for DSM-5 but relegated to Section III as a "condition for further research," defined by subthreshold delusions, hallucinations, or disorganised speech with relatively intact reality testing, occurring at least once weekly for the past month and worsening in the past year.

Diathesis-Stress Model

An explanatory framework proposing that schizophrenia manifests when underlying biological or genetic vulnerabilities (diathesis) interact with neuromaturational events and psychosocial or environmental stressors (e.g., family conflict, adverse life events).

Expressed Emotion (EE)

A family relational climate characterized by high levels of criticism, overt hostility, and emotional overinvolvement, which strongly predicts relapse in individuals recovering from active schizophrenia episodes.

Clinical High Risk for Psychosis (CHR-P)

A clinical designation for individuals, particularly adolescents and young adults, demonstrating attenuated psychotic symptoms or marked functional decline that indicate vulnerability for transitioning to overt psychosis.

Psychotic-Like Experiences (PLEs)

Subclinical psychotic phenomena reported in young people that do not meet full criteria for a psychotic disorder but indicate elevated risk; strongly correlated with early use of substances including cannabis, alcohol, tobacco, and amphetamines.

Antipsychotic Medications

The primary pharmacological frontline treatment for schizophrenia (first and second generation), functioning primarily via blockade of dopamine $D_2$ receptors to control active psychotic symptoms and delay relapse.