Mental health

How does the body function

• The body functions through biochemistry and chemical signaling.

• Hormones, neurotransmitters, and other biochemical molecules regulate cognition, memory, sleep, and higher-order functions.

How do many mental illnesses start?

from chemical imbalances in the brain

Brain

• The brain controls both autonomous (unconscious) and voluntary (conscious) functions.

• It regulates behavior, self-control, sleep, and emotions.

• Some behaviors are controllable, while others (e.g., OCD) are compulsive and harder to regulate.

Genetics and Personality

• Genetics influence mental health and personality traits.

• Different neurotransmitter balances contribute to different personalities.

• Genome sequencing helps identify susceptibility to mental illnesses like Alzheimer's and Parkinson’s.

Historical Perspectives on Mental Health

• In the past, mental illnesses were attributed to supernatural causes (e.g., demons).

• Early treatments included trepanation (drilling holes in the skull), lobotomies, and electroshock therapy.

Development of Psychiatric Medications

• 1950s saw the emergence of effective psychiatric drugs.

• Schizophrenia involves loss of reality, hallucinations, paranoia, and anxiety.

• Early treatments included antihistamines (e.g., Promethazine, Thorazine), which helped calm patients but did not fully address all symptoms.

• Histamines (chemical messengers) play roles in both allergic responses and brain function (e.g., sleep-wake cycles).

• Some psychiatric drugs induce sleep by blocking histamines, which can help with anxiety but not other symptoms of mental illness.

How do antidepressants work?

• Many antidepressants work by preventing the reuptake of neurotransmitters (e.g., serotonin, norepinephrine, dopamine) in the synaptic cleft, increasing their availability and enhancing mood.

Monoamine Oxidase Inhibitors

• Monoamine Oxidase (MAO) is an enzyme that breaks down neurotransmitters like serotonin.

• MAOIs inhibit this enzyme, leading to higher serotonin levels and mood enhancement.

• However, early MAOIs caused serious side effects, such as liver toxicity (hepatotoxicity), leading to their discontinuation in favor of safer drugs.

TCAs

• were early antidepressants that worked by blocking serotonin and norepinephrine reuptake.

• They were effective but had major side effects, including:

  • Drowsiness (due to histamine receptor antagonism).

  • Dry mouth and memory issues (due to acetylcholine receptor antagonism).

  • Cardiovascular risks, making them dangerous in overdose situations.

SSRIs (Selective Serotonin Reuptake Inhibitors)

• Specifically target serotonin reuptake without affecting histamine, dopamine, or acetylcholine systems.

• Fewer side effects compared to TCAs and MAOIs.

• Better safety profile, making them more suitable for long-term use.

Obsessive-Compulsive Disorder (OCD

• OCD is linked to serotonin dysregulation, leading to compulsive behaviors, obsessive thoughts, and anxiety.

• Symptoms include:

  • Ritualistic behaviors (e.g., repeatedly checking locks, excessive handwashing).

  • Perfectionism over minor details (e.g., aligning objects in a specific order).

• SSRIs like Prozac are commonly used to increase serotonin levels and alleviate OCD symptoms.

• Newer MAO inhibitors also show promise in treating OCD.

Bipolar Disorder and Chemical Imbalance

• Bipolar disorder causes extreme mood swings, with alternating manic (high-energy) and depressive (low-energy) episodes.

• Early theories (e.g., John Cade’s toxin hypothesis) suggested that toxins in the blood caused manic episodes.

• Today, research points to neurotransmitter dysregulation, particularly involving serotonin, dopamine, and norepinephrine.

• Lithium is the primary treatment, helping stabilize mood by modulating neurotransmitter activity.

Anxiety Disorders & Treatments

• Related to increased adrenergic (adrenaline) response.

• Barbiturates (discovered in 1864) were found to have anti-anxiety effects.

• Barbiturates target GABA receptors, reducing neuronal activity (anxiolytic & hypnotic).Benzodiazepines (e.g., Valium, Xanax) replaced barbiturates as a safer alternative.

• Benzodiazepines amplify GABA signaling by increasing receptor sensitivity.

Psychiatric Medications & Challenges:

• Psychiatric drugs (e.g., Prozac, Valium) alter neurotransmission.

• Critics argue they lack precise control over brain chemistry, leading to side effects.

• Placebo effect plays a significant role in drug efficacy, influencing patient response.

• Some psychiatric drugs are highly addictive and cause withdrawal symptoms.

Placebo Effect in Clinical Trials:

• Placebos (sugar pills) are used as a control to measure drug effectiveness.

• Placebo responses can mimic drug effects, making efficacy assessment complex.

• Some individuals experience side effects from placebos (e.g., nausea, headaches, rashes).

Limitations in Psychiatric Drug Development:

• Progress in psychiatric drugs has been slow compared to other fields like computing.

• Most new drugs are minor modifications of older ones, reducing side effects but offering little improvement in efficacy.

• The brain's extreme complexity makes developing precise treatments challenging.

• The brain contains over 90 billion neurons and trillions of synapses, making targeted drug development difficult.