Neuropsychiatric Disorders and Autism Spectrum Diagnosis

Posted on May 27, 2026 in Psychology and Sociology

Eric John Ruiz (A18482438)

Week 4 – Neuropsychiatric Disorders: Diagnosis & Methods

Neuropsychiatric Disorders: Diagnosis and Methods

  • Mental Illness / Mental Health Disorders / Psychological Disorders
    • Patterns of thoughts, feelings, or actions that are “deviant,” distressing, and dysfunctional.
    • Disorders that affect mood, thinking, and behavior.
    • Associated with distress and/or problems with daily functions.

Key Terms and Epidemiology

Syndrome: Medical signs and symptoms associated with a particular disease or disorder; often interchangeable with “disorder.”

Epidemiology:

  • Prevalence: Percentage of people with a disorder.
    • Lifetime prevalence: At any point in life.
    • Point prevalence: At a specific point in time.
    • Period prevalence: During a given period of time.
  • Incidence: Number of new cases within a given period.

Etiology: The underlying cause of a condition.

Historical Figures in Psychiatry

  • Philippe Pinel: Pushed for better treatment of psychiatric patients.
    • Memoir on Madness (1794); advocated for moral therapy.
  • Antoine Laurent Bayle: Linked general paralysis of the insane (general paresis) to the pathological lesions of neurosyphilis; established clinical-pathological correlation.
  • Karl Kahlbaum: Identified classification commonalities among groups of patients.
  • Emil Kraepelin: Divided dementia praecox (schizophrenia) from manic-depressive illness.
    • Proponent of eugenics.

The Medical and Biopsychosocial Models

Medical Model:

  • “Mental” illness is due to physiology.
  • The same approaches used in medicine should be applied to mental illnesses.
  • Empirical proof is the best way to test medical theory.
  • An increased understanding of brain physiology will eventually improve patient care.

Biopsychosocial Model:

  • A holistic framework in healthcare positing that biological, psychological, and social factors interact to determine overall health and vulnerability to disease.
  • An alternative to the traditional medical model.

The Diagnostic and Statistical Manual (DSM)

Published by the American Psychiatric Association (APA):

  • DSM-I (1952): Classified 106 disorders.
  • DSM-II (1968): Focused on psychodynamic theory.
  • DSM-III (1980): Descriptive approach; removal of homosexuality as a disorder.
  • DSM-IV (1994): Classified 297 disorders; focused on disruption and distress.
  • DSM-5 (2013): Significant modifications; removed schizophrenia subtypes, recognized autism classifications under the umbrella of Autism Spectrum Disorders, and removed Axes categorizations.

Benefits of Standardized Classification

  • Standardizes diagnosis and treatment; diagnoses guide clinical care.
  • Provides verbal shorthand for symptoms; useful for research.
  • Patients may feel relief when they can name their symptoms.

Criticisms of the DSM

  • Oversimplification: Complicated by comorbidity, heterogeneity, and the continuation of symptoms.
  • Misdiagnoses and over-diagnoses (subjective nature).
  • Labeling and stigmatization.

Research Domain Criteria (RDoC)

  • A research framework for studying mental disorders focusing on dimensions of behavior and cognition.
  • Matrix of six major domains of human functions.
  • Units of analysis: Genes, molecules, cells, circuits, physiology, behaviors, self-report, and paradigms.

The Process of Modern Psychiatric Diagnosis

DSM classification is widely used for clinical diagnosis based on diagnostic criteria, though no “lab” test exists in most cases. For example, Major Depressive Disorder (MDD) is diagnosed by assessment.

  • Clinicians look at “signs and symptoms” rather than etiology.
  • Gathering information: The “LEAD Standard” uses reliable facts, medical records, and family reports rather than just the patient’s report.

Neuroimaging Methods in Psychiatry

  • Structural Imaging: MRI, DTI.
  • Functional Imaging: fMRI, PET, EEG, MEG, ECoG.

Structural MRI: Measures volume, cortical thickness, surface area, and shape. Volume is measured via manual tracing or automated software.

fMRI – BOLD Signal: Measures Blood Oxygen Level Dependent signal changes during tasks or at rest.

  • Functional connectivity: Correlation of BOLD activity between regions.
  • Resting state: Measures BOLD fluctuations when the subject is not performing a task.
  • Regions that are functionally related show highly correlated activity.

Common fMRI Studies:

  • Correlation between two regions (e.g., Left and Right motor FC).
  • Seed-based correlation (activity in one region vs. the rest of the brain).
  • Modular organization (functional systems).

Autism Spectrum Disorders: Methods and Diagnosis

Evaluating Neuroimaging Studies

When reviewing studies, consider:

  • Overinterpretations: Claims of finding the sole “cause” or single-function regions.
  • Reverse Inference: Assuming a mental state based on brain activation (e.g., “amygdala activation equals fear”).
  • Methodological Limitations: “The brain is not a bag of voxels.”
  • Common Confounds: Head motion, sample differences, and order effects.
  • Statistics: Misinterpreting lack of significance in one group as a definitive difference between groups.

The Evolution of Autism Diagnosis

  • Leo Kanner (1943): Credited with the first report, “Autistic disturbances of affective contact.”
  • Eugen Bleuler: Described schizophrenia detachment as “autistic.”
  • Pre-DSM-III: Broadly diagnosed as childhood schizophrenia or psychosis.
  • DSM-III (1980): Specified diagnostic criteria for autism.
  • DSM-IV (1994): Included Autistic Disorder, Asperger’s Disorder, and PDD-NOS.
  • DSM-5 (2013): Introduced the “spectrum” and collapsed subgroups into Autism Spectrum Disorder (ASD).

Clinical Features and Symptoms of ASD

ASD involves two major domains:

  1. Deficits in social communication and interaction:
    • Deficits in social-emotional reciprocity.
    • Deficits in nonverbal behaviors (eye contact, gestures, facial expressions).
    • Difficulties in developing and understanding relationships (struggles with irony, sarcasm, or shared play).
  2. Restricted and repetitive patterns of behavior:
    • Stereotyped motor movements (hand flapping) or repetitive speech (echolalia).
    • Insistence on sameness and routines.
    • Fixated interests of abnormal intensity.
    • Hyper- or hypo-reactivity to sensory input.

Epidemiology and Variability

  • Ratio: Approximately 3:1 or 4:1 male-to-female ratio.
  • Prevalence: Increased due to inclusive criteria, awareness, and methodology.
  • Comorbidity: Often occurs with ADHD, intellectual deficits, Fragile X syndrome, and epilepsy.
  • Diagnosis: Reliable by age 2, though many are diagnosed after age 4 or 6.

Cognition and Social Functioning

  • Face Processing: Eye-tracking shows reduced gaze toward eyes, declining between 2-6 months of age.
  • Joint Attention: Deficits in coordinating attention through eye contact or pointing.
  • Theory of Mind: Difficulty attributing mental states to others (e.g., failing the Change-of-Location False Belief Task).

Neuroanatomy and Treatment of Autism

Brain Structure:

  • Early Overgrowth: 5-10% enlarged brain volume in children aged 18 months to 4 years.
  • Synaptic Pruning: Evidence of failure in synaptic pruning in the temporal lobe.
  • Amygdala: Early enlargement noted in young children.
  • FFA (Fusiform Face Area): Altered activation during face processing.

Treatment:

  • Behavioral training: Applied Behavior Analysis (ABA) and CBT.
  • Speech, language, and occupational therapy.
  • Pharmacotherapy: Neuroleptics for aggression, SSRIs for anxiety, and Oxytocin for social bonding.

The Vaccine Controversy and Scientific Evidence

The Wakefield Study: Andrew Wakefield falsely claimed the MMR vaccine caused autism. The 1998 paper was fully retracted in 2010 after being discredited as fraudulent.

  • Anecdotal Evidence: Based on casual observations and confirmation bias; not scientifically reviewed.
  • Scientific Evidence: Peer-reviewed, large samples, statistically verified, and replicable.

The Danger of Vaccine Misinformation: Distracts from legitimate research and leads to the resurgence of deadly diseases like measles and pertussis (whooping cough).