Comprehensive Study Notes on Schizophrenia: Diagnostic Criteria, Symptoms, and Virtual Reality Research

Overview of Schizophrenia

• Schizophrenia is categorized as a psychotic disorder.

• It is characterized by significant disturbances across multiple aspects of an individual's life, including:

  • Thoughts

  • Feelings

  • Experience

  • Behaviour

Diagnostic Requirements According to ICD-11

• To receive a diagnosis of schizophrenia based on the International Classification of Diseases ($11^{th}$ Revision), the following criteria must be met:

  • At least $2$ symptoms must be present.

  • Included in these symptoms must be at least $1$ core symptom, categorized as items [a] to [d].

  • Symptoms must persist for a duration of at least $1$ month or more.

Categories of Symptoms and Clinical Presentation

• The ICD-11 identifies two primary categories of symptoms:

  • Positive symptoms

  • Negative symptoms

• Some individuals may experience prodromal symptoms prior to a formal diagnosis.

  • Prodromal symptoms are essentially weaker versions of the core symptoms.

Positive Symptoms of Schizophrenia

• Positive symptoms represent experiences that are "in addition to" or a "distortion" of normal experience.

• These symptoms add thoughts, feelings, or behaviours that were not previously there, generally referring to a distorted reality.

• Approximately $50-70\%$ of individuals with schizophrenia experience hallucinations, delusions, or both, according to Lindenmayer & Khan ($2006$).

Hallucinations

• Hallucinations involve the apparent perception of something that is not actually present. They can affect all five senses:

  • Auditory: Hearing things that are not real.

  • Visual: Seeing things that are not real.

  • Tactile: Feeling things that others do not feel, or the sensation of something touching the skin that isn't there.

  • Olfactory: Smelling odors that others cannot smell.

  • Gustatory: Tasting things that are not there.

Delusions

• Delusions are false beliefs held with strong conviction despite superior evidence to the contrary. They represent a significant misrepresentation of reality.

• Persecution (Paranoid): Fears that individuals, groups, or the government have malevolent intentions and are "out to get" the individual. This includes beliefs about being followed, harmed, poisoned, or tormented.

• Reference: The belief that gestures and words of others are specifically directed at the individual. This may involve the conviction that they are the focus of song lyrics, books, or comments made by a television presenter.

• Grandeur (Grandiose): The conviction that one possesses special powers, talents, or abilities. The individual may also believe they are a famous person or a specific character.

Disorganized Thinking (Thought Disorder)

• Irrelevant speech: Difficulty maintaining a coherent line of thought in conversation.

• Neologisms: The invention of new words or phrases (e.g., using "klipno" to refer to a watch).

• Word salad: Speech that is so incoherent it becomes entirely incomprehensible.

Experiences of Influence, Passivity, or Control

• The individual experiences their feelings, impulses, actions, or thoughts as being controlled by external forces. Specific examples include:

  • Thought insertion: The belief that thoughts are being put into one's mind.

  • Thought broadcasting: The belief that others can hear or perceive one's thoughts.

  • Thought withdrawal: The belief that thoughts are being taken out of one's head.

Negative Symptoms of Schizophrenia

• Negative symptoms occur when the level of functioning or experience falls below normal levels.

• These symptoms involve a loss or reduction in normal behaviour, thought, or feeling, particularly in areas of speech, affect, and motivation.

• Approximately $25\%$ of schizophrenics experience negative symptoms (Cohen et al., $2013$).

Types of Negative Symptoms

• Flat Affect: A lack of outward emotional expression. Signs include staring vacantly, motionless facial muscles, lifeless eyes, and replying in a flat, toneless voice without making eye contact.

• Asociality: A reduction in social initiative that impairs relationships. It manifests as poor social skills and a general social disinterest.

• Alogia: A significant reduction in the total amount of speech. Individuals do not talk much, give short one or two-word replies, and do not elaborate with additional detail.

• Avolition: A lack of motivation or an inability to persist in activities such as hobbies, school work, or social engagements.

• Anhedonia: A loss of interest in or a reported lessening of the experience of pleasure.

Psychomotor Disturbances

• Catatonia: Characterized by a lack of movement and communication. Specific features include:

  • Negativism: Showing little or no response to instructions or external stimuli.

  • Mutism: The inability to talk.

  • Posturing: Actively holding a posture against the force of gravity.

  • Waxy Flexibility: A state where an individual's limbs can be moved into a position by someone else and will remain in that position.

Case Study: Aneja et al. (2018)

• Subject: A $14$-year-old boy.

• Symptom Progression:

  • Age $11$: Academic decline, handwriting deterioration, irritable and sad behaviour.

  • Subsequent years: Hearing voices for two years, aggressive behaviour, resentment regarding eating with family, decline in daily routine performance, and preference for solitary activities.

• Clinical History:

  • Treated with sodium valproate at age $11$, but the diagnosis was deferred at that time.

  • Voices began appearing more clearly over the next year.

  • Diagnosed with early-onset schizophrenia.

  • The patient eventually dropped out of school and showed further deterioration in socialization and self-care.

• Treatment:

  • Multiple hospital admissions.

  • Administered various medications and treatments, including Elektroconvulsive Therapy (ECT), psychotherapy, and occupational therapy.

• Outcomes:

  • No episodes of violence in the final six months reported.

  • However, poor socialization, lack of motivation, apathy, and aversion to school remained unresolved.

Key Study: Virtual Reality and Persecutory Ideation (Freeman et al., 2003)

Context and Theory

• Virtual Reality (VR) was introduced to psychology in the early $1990\text{s}$ and $2000\text{s}$, proving useful for treating anxiety disorders and phobias via exposure therapy.

• Persecutory Ideation: The belief that others are being hostile or have negative feelings toward you. It is one of the most common symptoms of schizophrenia and can lead to total social withdrawal.

• VR allows for the study of persecutory ideation in non-clinical populations to understand this complex symptom better.

Aims and Hypotheses

• Aim 1: To investigate if VR technology permits the investigation of persecutory ideation.

• Aim 2: To study whether non-clinical individuals have persecutory thoughts in VR.

• Hypothesis: A small proportion of individuals would experience persecutory thoughts in a neutral VR environment and would correlate with higher trait paranoia and emotional distress.

Methodology

• Sample: $24$ non-clinical participants ($21$ students, $3$ administrative staff) from University College London (UCL).

  • $12$ males, $12$ females.

  • Mean age = $26$.

  • Recruited via volunteer sampling; no history of mental illness.

• Apparatus: VR simulation of a neutral library scene containing $5$ avatars exhibiting ambiguous behaviours (smiling, looking, talking).

• Design: Covert, non-participant observation and self-report (interviews, questionnaires, psychometric tests).

Procedure

1. Training: Participants were trained to use VR equipment.

2. Instructions: Participants were told to explore the room and form impressions of the avatars and what the avatars thought of them.

3. VR Task: Participants spent $5$ minutes in the virtual library.

4. Post-VR: Participants completed questionnaires and a short semi-structured interview (videotaped).

5. Compensation: Participants were paid for their time.

Measures and Psychometric Tests

• Brief Symptom Inventory (BSI): $53$ items assessing $9$ dimensions (e.g., interpersonal sensitivity, depression, anxiety, hostility, psychoticism).

• Paranoia Scale: $20$ items measuring ideas of persecution and reference. Scores range from $20$ to $100$.

• Spielberger State Anxiety Questionnaire: Measures current anxiety levels.

• VR Paranoia Questionnaire: A $15$-item, situation-specific scale devised for this study. Uses a $4$-point scale ($0$: Do not agree, $1$: Agree a little, $2$: Agree moderately, $3$: Totally Agree).

• Interview Rating: Videotaped interviews were rated on a $6$-point scale for persecutory content by a clinical psychologist.

• Priming Control: To check for priming, half the participants took questionnaires only after VR, and the other half took them both before and after.

Results and Findings

• General Impressions: Positive views of avatars were the most frequent.

• Persecutory Thoughts: Some participants reported ideas of reference or persecution (e.g., "Someone in the room had it in for me" or "They were talking about me behind my back").

• Specific Comments (Negative):

  • "They were very ignorant and unfriendly."

  • "One person was very shy and another had hated me."

  • "The two women looked more threatening."

  • "They were telling me to go away."

• Correlations:

  • Significant correlation between paranoia questionnaire scores and the interview-based paranoia score.

  • No significant difference in persecution scores between genders.

  • No significant difference between those tested before/after versus those tested only after.

  • Predictive Factors: Interpersonal sensitivity and anxiety (on the BSI) were significantly correlated with higher persecutory thoughts in VR.

Summary of Freeman et al. (2003)

• Individuals attribute mental states to VR characters, even knowing they are computer-generated.

• Vulnerability to perceiving persecutory intent arises partly from anxiety and interpersonal sensitivity.

• Interpersonal sensitivity is the most significant predictor of persecutory ideation in virtual environments.

• VR is a promising tool for evaluating and reducing persecutory thoughts effectively.