Mental health

Stress Response

• The sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis are key physiological systems involved in responding to stress
• They work together to prepare the body for "fight or flight" reactions to perceived threats

Sympathetic Nervous System (SNS)

• It is part of the autonomic nervous system, controlling involuntary bodily functions
• The SNS plays a central role in immediate, short-term responses to stress
• Activation leads to rapid physiological changes preparing the body for quick action

SNS Key Mechanisms

• Activation of the adrenal medulla leads to the release of adrenaline (epinephrine) and noradrenaline (norepinephrine) into the bloodstream
• Increased heart rate prepares the body to deliver oxygen and nutrients to muscles and vital organs
• Increased blood pressure occurs as blood vessels constrict to ensure blood flow to essential organs
• Pupils dilate to improve vision and awareness
• Airways dilate to allow more oxygen intake, supporting metabolic demands
• The liver increases glucose release into the bloodstream, providing energy for muscles
• Inhibition of non-essential functions like digestion and immune responses prioritizes immediate survival

Hypothalamic-Pituitary-Adrenal (HPA) Axis

• It regulates the body's long-term response to stress, involving hormone signaling to maintain homeostasis during prolonged stress

HPA Axis Key Mechanisms

• The hypothalamus activates upon stress perception, releasing corticotropin-releasing hormone (CRH)
• CRH stimulates the anterior pituitary gland to release adrenocorticotropic hormone (ACTH) into the bloodstream
• ACTH stimulates the adrenal cortex to release cortisol
• Cortisol increases glucose availability by promoting gluconeogenesis in the liver
• Cortisol has anti-inflammatory effects, suppressing immune responses in the short term
• Cortisol helps regulate the body’s circadian rhythm and manages longer-term energy needs
• Cortisol supports the body in coping with stress by enhancing alertness and memory formation

HPA Axis Feedback Loop

• It operates on a negative feedback loop
• Sufficient cortisol levels signal the hypothalamus and pituitary to reduce CRH and ACTH release
• This reduces cortisol production, preventing excessive secretion

Coordinated Action of SNS and HPA Axis

• The SNS provides an immediate "fight or flight" reaction, quickly mobilizing energy for physical responses
• The HPA axis initiates a more gradual response to manage prolonged stress
• Cortisol sustains increased energy demands and regulates other processes, like immune function

Interplay Between the Two Systems

• The SNS and HPA axis are distinct systems but interconnected
• SNS activation can activate the HPA axis
• Hormonal changes from the HPA axis, like cortisol release, enhance the SNS's stress response

Chronic Stress Effects

• It can dysregulate the HPA axis, leading to elevated cortisol levels
• This can cause immune suppression, sleep disturbances, and mental health conditions like anxiety and depression
• Chronic SNS activation can contribute to high blood pressure, cardiovascular problems, and gastrointestinal issues

Chronic Activation and Mental Illness

• Sustained stress response activation impacts the brain and body
• Prolonged release of stress hormones like cortisol and adrenaline, while helpful for acute adaptation, can be damaging when consistently high

Chronic Cortisol Release and Brain Structure

• Cortisol is crucial for energy and immune regulation, but persistent elevation due to stress harms brain areas for mood, memory, and decision-making

Brain Region Impact

• The hippocampus is critical for memory and emotional regulation
• Chronic high cortisol can shrink the hippocampus, impairing memory and increasing depression/anxiety vulnerability
  • Cortisol inhibits brain-derived neurotrophic factor (BDNF)
  • BDNF is needed for neuron growth and repair, especially in the hippocampus
  • BDNF reduction impairs neurogenesis and contributes to cognitive decline
• The prefrontal cortex (PFC) involved in higher cognitive functions like planning and emotion regulation
  • Chronic stress impairs PFC function, reducing emotional management and decision-making ability
  • Can lead to problems with impulse control and vulnerability to anxiety/depression
    • Chronic cortisol release may disrupt PFC connectivity, hindering emotional regulation and stress coping
• The amygdala, responsible for processing emotions, especially fear
  • Chronic stress increases amygdala activation, hyper-responsiveness to threats, heightened anxiety, paranoia, and emotional dysregulation
  • Contributes to anxiety disorders, PTSD, and panic attacks

HPA Axis and Mood Disorders

• A healthy HPA axis controls cortisol levels with feedback mechanisms
• In chronic stress, the system can become dysregulated

Consequences of HPA Axis

• Hyperactivity occurs when the HPA axis becomes overactive
  • This leads to consistently high cortisol even without stress
  • Commonly seen in depression
  • High cortisol is thought to contribute to emotional and cognitive symptoms
• Hypoactivity results from the HPA axis becoming underactive in chronic stress
  • Results in inadequate cortisol response when needed
  • Observed in some cases of PTSD
  • Impairs the ability to cope with future stressors
• HPA axis dysregulation creates a feedback loop
  • The body is unable to appropriately adjust cortisol levels
  • Increases susceptibility to mental health disorders like depression, anxiety, and bipolar disorder

Neuroinflammation and the Immune System

• Chronic stress increases inflammation in the body and brain
• Stress activates the immune system
• The activated immune system causes the release of pro-inflammatory cytokines, impacting brain function
• Implicated in several mental health disorders

Key Points

• Cytokines and Depression
  • Inflammation is linked to depression
  • Elevated pro-inflammatory cytokines disrupt neurotransmitter systems regulating mood, leading to depression symptoms
• Neuroinflammation and Anxiety
  • Chronic stress-induced inflammation affects the hippocampus and amygdala
  • Amplifies emotional/stress responses and contributing to anxiety, panic disorders, and PTSD

Altered Neurotransmitter Systems

• Chronic stress leads to dysregulation of brain neurotransmitter systems for mood regulation
• Particularly serotonin, dopamine, and norepinephrine
• These neurotransmitters regulate mood, energy, and motivation
• Disruptions are central to many mental health conditions

Neurotransmitter disruption results:

• Serotonin: Chronic stress may reduce serotonin levels or impair function
  • Contributes to depression, anxiety, and obsessive-compulsive disorder (OCD)
  • Serotonin is critical for emotional stability
  • Deficits can lead to mood swings, irritability, and hopelessness
• Dopamine: The dopamine system is involved in reward processing and motivation
  • Chronic stress can decrease dopamine production
  • Leads to symptoms of anhedonia (inability to feel pleasure)
  • Anhedonia is a hallmark of depression
• Norepinephrine: Elevated levels are associated with the "fight or flight" response
  • Elevated levels can lead to increased arousal, hypervigilance, and heightened anxiety
  • Dysregulation is often observed in PTSD and generalized anxiety disorder (GAD)

Mental Health and Sleep Disturbances

• Chronic stress often leads to sleep disturbances like insomnia or poor-quality sleep
• Sleep disturbances can exacerbate mental health problems
• Stress-related sleep disruptions increase the body's stress response, elevating cortisol and making brain recovery from stress more difficult

Sleep and Mood Disorders

• Cognitive Impairment occurs from a lack of restorative sleep
  • Can impair cognitive functions like attention, memory, and emotional regulation
  • Increases vulnerability to conditions like depression and anxiety
• Emotional Dysregulation occurs from sleep deprivation
  • Impacts the amygdala
  • Makes it more reactive to emotional stimuli
  • Exacerbates mood disorders

Impact on Coping Mechanisms and Behavior

• Chronic stress can weaken effective coping mechanisms and lead to maladaptive behaviors for mental illness

Includes:

• Avoidance behaviors
  • Chronic stress may lead to avoidance of situations that cause anxiety
  • Increases isolation, reinforcing feelings of helplessness and depression
• Substance abuse
  • People under chronic stress may turn to alcohol, drugs, or other substances as a way to self-medicate
  • Can lead to substance use disorders
  • Further exacerbates mental health conditions like depression and anxiety

Conclusion: Stress and Mental Illness

• Chronic activation of the stress response contributes to mental health disorders through:
  • Altering brain structures involved in emotional regulation
  • Dysregulating neurotransmitter systems critical for mood and motivation
  • Promoting neuroinflammation that disrupts normal brain functioning
  • Increasing vulnerability to mood disorders like depression, anxiety, PTSD, and substance use disorders
• Over time, these biological and behavioral changes create perpetuates the cycle of stress and mental illness making it harder for the individual to recover without intervention
• Underscores the importance of managing chronic stress through therapeutic strategies, such as cognitive behavioral therapy (CBT), mindfulness, relaxation techniques, and medication

Cortisol -Textbook Notes

• Cortisol has anabolic effects on protein metabolism by increasing the rate of protein synthesis and ribonucleic acid (RNA) in the liver
• Cortisol effect is countered by catabolic effect protein stores in other tissues
• Protein catabolism acts to increase levels of circulating amino acids
• Chronic exposure to excess cortisol can severely deplete protein stores in muscle, bone, connective tissue, and skin

Schizophrenia Symptoms

Schizophrenia

• Is a complex and chronic mental health disorder that affects how a person thinks, feels and behaves
• Schizophrenia characterized by a combination of positive, negative and cognitive symptoms that vary in intensity and duration

Positive Symptoms

• Positive symptoms refer to behaviors or experiences that are added to the persons normal functioning
• Positive symptoms exaggerate or distort normal thoughts, perceptions or behaviors and are associated with psychosis (loss of contact with reality)

Common Positive Symptoms

• Hallucinations: false perceptions that occur without external stimulus
  • Most common type of hallucination in schizophrenia: auditory hallucinations
  • Where person heards voices that others do not hear Other hallucinations can include: visual, olfactory (smelling) , or tactile
• Delusions: false beliefs that are strongly held despite evidence to the contrary.
  • Persecutory delusions: Beliefs that others are plotting to harm or spy on the person Thinking they are being followed or watched by the government
  • Grandiose Delusions: Beliefs the person has exceptional abilities wealth or fame or is on a special mission
  • Referential delusions: belief ordinary events , objects or people have special meaning or significance for the person Thinking news reports or songs are specifically directed at them.

Disorganized Thinking

• Disorganized Thinking (Speech) Disorganized thinking can result in incoherent speech or loose associations where thoughts may become fragmented or illogical and difficult for others to follow
  • Tangential speech: Moving off-topic without returning to the original point.
  • Word salad: A jumble of words that doesn’t make sense.
• Disorganized or Abnormal Motor Behavior: ranges of disruptive or bizarre behaviours Catatonia: range of behaviours with lack of movement or responsiveness or excessive, purposeless movement Inappropriate posturing or odd facial expressions.

Symptoms Impact

• Positive symptoms are often associated with schizophrenia and medical intervention
• These symptoms be managed with antipsychotic medications (e.g. dopamine antagonists) & reduce intensity of hallucinations/delusions.

Negative Symptoms

Negative Symptoms

• Consist of a diminishment or absence of normal functioning
• Affect an individuals ability to perform everyday tasks, engage socially, and feel motivated or connected

Common Negative Sx

• Avolition: a lack of motivation or drive to to initiate and complete activities. Neglect personal hygiene/ able to complete work or daily tasks or goals.
• Alogia: reduce speech output often referred to as poverty of speech.
  • Poverty of content: Speaking with long-winded explanations that ultimately lack meaning or substance.
  • Alogia: Limited speech that is brief and doesn’t elaborate , sometimes referred to as “poverty of speech."
• Anhedonia: A diminished ability to experience pleasure or interest in activities that once brought enjoyment interest in hobbies or social relationships.
• Flat Affect: A reduced emotional expression, appears emotionally blunted , monotone , lack of emotional depth , or unresponsive.
• Social Withdrawal: Lack of interest in interacting with maintaining and relationships. Isolation , withdrawal from family and friends and reduction in social engagement.

Negative Symptoms Impact

• Negative symptoms are challenging to treat and tend to be persistent to antipsychotics impacting an individuals daily functions and well being.

Cognitive Symptoms

Cognitive Symptoms Definition

• Relate to Impairments in functions such as memory , Attention, & executive processing and often occur alongside positive and negative symptoms
  • Are not readily apparent and affect individual in their ability to function effectively in society

Common Cognitive Symptoms:

• Impaired Attention : Difficulty focusing on tasks or conversation Inability to complete tasks or redirection.
• Working Memory Deficits: : forget recently said things inability to do simple tasks).
• Impaired Executive Functioning: difficulty planning and problem solving , decision-making & multi-tasking difficulty one's thoughts/actions.
• Processing Speed: difficulty keeping up completing tasks or responding in real-time.
• Impaired Insight: difficulty recognizing or understanding that they are experiencing symptoms of the illness. harder to seek help or comply to treatment.

Cognitive symptoms impact

• Affects person's ability function independently , memory , attention and executive process
• Cognitive impairments or rehabilitation