U4 Psychiatric Disorders

Psychiatric Disorders

Incidence and Prevalence

  • Ubiquity in Society

    • Psychiatric disorders are common in contemporary U.S. life.

    • Estimated that 1 in 5 individuals suffer from a significant psychiatric disorder during any given year.

  • Age of Onset

    • More than 50% of psychiatric disorders begin before the age of 14.

    • 75% of disorders have their onset by age 24.

  • Major Psychiatric Disorders

    • 1 in 20 adults live with major psychiatric disorders such as schizophrenia, bipolar disorder, or major depression.

  • Risk Factors

    • Individuals who do not conform to binary sexual norms (gender nonconforming, LGBTQQIAAP) are at increased risk for mental health issues, including anxiety, depression, substance misuse, and suicidal ideation.

Coexisting Psychiatric Disorders

  • Individuals with physical or cognitive disorders show higher prevalence rates of coexisting psychiatric disorders.

  • 50% of those affected by substance use disorders also have a coexisting psychiatric disorder.

  • The most common mental health problems in the U.S. include depression, anxiety, and substance use disorders (Long, 2024, p. 537; Takahashi, 2023, p. 618).

Understanding Psychiatric Disorders

Etiology of Psychiatric Disorders

  • Emerging evidence supports that psychiatric disorders may have multiple etiologies.

  • Two Basic Frameworks (Traditional vs. converging theories)

    1. Environmental and Psychosocial Models (Nurture)

    • Based on psychoanalytic theories evolving from Freud's psychology

    • Psychological factors: stress, loss of a parent, neglect.

    • Environmental factors: dysfunctional family dynamics, cultural expectations, substance use (Long, 2024, p. 537).

    1. Biological Factors (Nature)

    • Include genetics, infections, brain defects or injury, malnutrition, toxin exposure, fetal developmental issues.

    • Chemical imbalances result from excess or deficiency of neurotransmitters; medications aim to restore balance.

    • Majority of individuals in public health systems have been impacted by severe trauma throughout their lives (Long, 2024, p. 537).

The Role of Genetics

Genetic Influence on Psychiatric Disorders

  • No definitive genetic links to specific disorders established.

  • Genetic vulnerability and environmental influences significantly interact:

    • Epigenetics: The interplay where the environment modifies gene activity.

    • Endophenotypes: Specific phenotypes that have a clear genetic correlation to psychiatric illnesses.

  • The mechanisms behind psychiatric disorders indicate a complex interplay of psychological, sociocultural, developmental, and biological factors (Long, 2024, p. 537).

The Stress-Diathesis Theory

Overview of the Model

  • Developed to explain how environmental stressors and genetic predisposition contribute to psychiatric disorders.

  • Individuals with genetic vulnerability may experience significant stressors (e.g., trauma or neglect), leading to the expression of psychiatric conditions.

  • Individuals without genetic predisposition may require more stressors to develop disorders.

  • For certain disorders (e.g., PTSD, phobias), extreme stress can trigger symptoms in those who might not be genetically predisposed

Trauma's Role

  • Trauma underlies many psychiatric disorders and medical illnesses.

  • More than 50% of people report experiencing at least one traumatic event; an average of 5 traumatic events per individual.

  • Individual response to trauma varies, affected by age, coping skills, support systems, cognitive deficits, neural physiology, and trauma nature (Long, 2024, pp. 537-538).

  • Adverse Childhood Experiences (ACEs) are correlated with later-life mental health issues and disorders such as alcohol use disorders and severe mental illness.

Neurochemicals

Overview

  • Neurochemicals and neurohormones mediate responses to stress.

  • Messenger Molecules: Include amino acids, hormones, neurotransmitters, immune cells, and neuropeptides.

  • More than 300 messenger molecules are identified as crucial.

  • Neurotransmitters facilitate signal transmission across synapses (Long, 2024, pp. 538-539).

Key Neurotransmitters

  • Important Neurotransmitters:

    • Acetylcholine: Both excitatory and inhibitory roles.

    • Dopamine: Also involved in reward mechanisms.

    • Glutamate: Excitatory neurotransmitter facilitating brain activity.

    • Gamma-Aminobutyric Acid (GABA): Inhibitory neurotransmitter functioning as a natural tranquilizer.

    • Norepinephrine and Epinephrine: Both have excitatory effects; related to stress responses.

    • Serotonin: Influences mood and anxiety regulation.

Hormonal Influences

  • Corticotropin-Releasing Hormone (CRH) and the HPA Axis regulate stress adaptation. ACES are disruptive to these systems.

  • Cortisol: Released during stress response; influences several bodily functions, but excessive levels can have damaging effects.

  • Dehydroepiandrosterone (DHEA): Released alongside cortisol; aids learning and may improve cognition under stress

Types of Psychiatric Disorders

Schizophrenia

  • Definition: Schizophrenia is a chronic debilitating psychotic disorder affecting approximately 1% of the population.

  • Characteristics: Impairment in thoughts, feelings, perceptions, and behaviors; interferes with environmental stimuli filtering.

  • Onset: Typically occurs between ages 16 and 30.

  • Genetic predisposition: Individuals with first-degree relatives have 10 times greater prevalence.

  • Dysregulation of dopamine and serotonergic systems

  • Symptoms include:

    • Delusions

    • Hallucinations

    • Impaired reasoning and social dysfunction

  • Diagnostic criteria: Presence of ≥ 2 psychotic manifestations lasting 6 months or more (Long, 2024, p. 541).

Mood Disorders

  • Prevalence: Estimated 50% of those needing treatment for mood disorders go undiagnosed.

  • 12-month prevalence: Approximately 9.5% in the U.S.

  • Lifetime prevalence: Roughly 16.2%.

  • Higher rates in families with a history of mood disorders.

  • Major depressive disorder more common in assigned-at-birth females than assigned-at-birth males after adolescence.

  • Depression rates are disproportionate among individuals living in poverty; 2-6% of children and adolescents affected

Depressive Disorders

  • Types: Eight recognized types of depressive disorders.

  • Variance in intensity; often recurrent.

  • Major Depressive Episodes (MDE): Occur annually in 6.7% of adults and 12.8% of adolescents.

  • Average onset: mid-30s, with increasing MDE rates in younger populations.

  • Older adults often present with confusion; untreated episodes can lead to neurocognitive disorders

Major Depressive Disorder (MDD)

  • Caused by depletion of serotonin, epinephrine, and/or dopamine in the CNS

  • Defining Characteristic: Loss of interest in activities, resistance to engagement.

  • One of the leading causes of disability

  • Common symptoms: Lack of appetite, inability to concentrate, feelings of worthlessness, and recurring thoughts of self-harm.

  • Diagnostic criteria: Symptoms present for ≥ 2 weeks, interfering with daily functioning

Persistent Depressive Disorders (Dysthymia)

  • Definition: Chronic but mild depressive state lasting at least 2 years.

  • Etiology is idiopathic; stress may play a role.

  • At least 2 symptoms for diagnosis: altered sleep pattern, eating patterns, fatigue, inability to concentrate, low self-esteem, hopelessness

  • Higher levels of C-reactive proteins→ depression is linked to chronic inflammation

Bipolar Disorder

  • Strong genetic component

  • Definition: Mood disorder with both manic and depressive episodes, lifetime prevalence of 2.5%.

  • Must have MDD symptoms

  • Median age at onset: 25 years; often presents during adolescence.

  • Individuals may go undiagnosed for 10 years following symptom onset s

  • Types: 4 bipolar disorders exist based on symptoms:

    1. Bipolar I Disorder: At least 1 manic episode.

    2. Bipolar II Disorder: Combination of MDD and at least 1 hypomanic episode.

    3. Cyclothymia: Less severe manifestations persist for 2 years (adult) or 1 year (children/adolescents).

    4. Rapid Cycling: 4 or more manic episodes annually

Anxiety Disorders

  • Definition: Characterized by intense, unfounded fear without a triggering event.

  • Patho: under-activation of serotonergic system and overactivation of adrenergic (cortisol), hyperactive amygdala, limbic and prefrontal cortex

  • Most prevalent psychiatric disorders, affecting about 18.1% of the U.S. population; higher prevalence in females.

Types of Anxiety Disorders

  • Generalized Anxiety Disorder (GAD): Characterized by excessive worrying about future events; difficulty controlling worry; potentially co-occurring depression. - Diagnosis requires chronic anxiety affecting daily relationships for ≥ 6 months

  • Common in older adults

  • Phobias: Irrational fear of minimal real threats; common types include situational and social anxiety disorders.

  • Panic Disorder: Characterized by recurrent panic attacks lasting 15-30 minutes; linked to early life traumas

Substance Use Disorders (SUD)

  • Definition: Encompasses both substance use and dependence associated with various substances (alcohol, opioids, etc.); U.S. annual prevalence is 8.1%.

  • Around 40% have co-occurring mental illnesses.

Neurophysiology of SUD Symptoms

  • Etiology is complex and multifactorial, with genetic and environmental factors both playing significant roles; dopamine pathways are notably affected

  • May be up to 50% inheritable

Disorders of Memory and Cognition

  • Cognition Definition: Processes wherein sensory input is stored, retrieved, and manipulated.

  • Memory Definition: Mental processes for acquiring, storing, and retrieving information crucial for reasoning and decision-making

Normal Cognitive Aging

  • Cognitive abilities decline slowly during aging; however, learning new information might be slower, while vocabulary remains intact

Neurocognitive Disorders (NCD)

  • Definition: Decline in mental function affecting daily activity capacity, not part of normal aging; affects 13.8% of individuals aged 72 and older

  • Individual NCDs present with unique manifestations across cognitive domains including memory, language, and social cognition