Phenylketonuria (PKU)

• Brain health influences behavior and is affected by genetics, life experiences, and epigenetic effects transmitted across generations.

Phenylketonuria (PKU)

• PKU is a condition where newborns develop symptoms leading to physical and cognitive disability.
• Symptoms: Musty odor in breath, skin, or urine, skin rashes, seizures, delayed development, hyperactivity, emotional, social, intellectual problems, and psychiatric disorders.
• PKU is caused by a single brain abnormality
• It is an autosomal recessive disorder affecting over 10,000 newborns globally each year.
• It is the most common inherited metabolic disease.
• PKU results from a defect in the gene for phenylalanine hydroxylase (PAH), an enzyme that breaks down phenylalanine.
• The defect causes excess phenylalanine to build up in the brain.
• Phenylalanine is a precursor molecule for neurotransmitters like norepinephrine and dopamine.
• Abnormality in PAH can be caused by more than 1000 naturally occurring mutations in the PAH gene.
• Both parents must carry a defective version of the gene to inherit PKU.
• The recessive condition can confer resistance to certain fungal toxins in some instances, and can be treated by restricting dietary intake of phenylalanine.
• High-protein foods like beef, fish, cheese, and soy contain large amounts of phenylalanine.
• A strict diet in infancy prevents brain damage, and maintaining a controlled diet throughout life ensures protection.
• Full understanding of PKU treatment requires understanding cultural, sex, and ethnographic differences in diet and protein metabolism.

Clinical Neuroscience

• Clinical neuroscience views the brain as the origin of behavior and studies diseases and disorders affecting it.
• It involves a variety of professionals diagnosing and providing therapy for behavioral disorders.
• Psychologists deal with behavioral problems.
• Psychiatrists deal with problems related to brain dysfunction.
• Neurologists deal with problems related to nervous system damage.
• Professionals should be considered the last line of defense for brain health.
• The World Health Organization defines health as including emotional, environmental, financial, intellectual, occupational, physical, social, and spiritual health.
• Family, friends, and community are the actual frontline workers for an individual's health and join practitioners as participants in treatment.

Behavioral Disorders

• Can be caused by genetic abnormalities, nervous system development, and environmental and epigenetic effects that modulate genetic and developmental expression.
• Diagnosable behavioral disorder affects 1 in 4 people in the US each year and nearly half the population over their lifetime.
• Only a minority receive treatment of any kind, and even fewer receive treatment from a mental health specialist.
• Behavioral, psychiatric, and neurological disorders are the leading cause of disability after age 15.

Diagnosing Behavioral Disorders

• Diagnostic information is gathered from both the patient and caregivers/family who know the patient.
• People are often not objective observers of their own behavior or that of a loved one.
• Nor are people often specific in identifying symptoms.
• Behavioral information about patients may be interpreted differently by general physicians, psychiatrists, neurologists, psychologists, social workers, and others.

Classifying Behavioral Disorders

• Classification systems help gain insights into biological processes and generate theories.
• The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) is the best-known and widely used classification system to aid diagnosis and treatment.
• The Research Domain Criteria (RDoC), launched by NIMH, aims to understand mental health and illness in terms of varying degrees of dysfunction in general psychological/biological systems.

Causes of Disordered Behavior

• Neuroscientists presume that abnormal brain functioning results in disordered behavior.
• General causes of abnormal brain function:
• Genetic errors that affect a chromosome, a constellation of genes, a single gene, or a single nucleotide polymorphism
• Epigenetic mechanisms that work prenatally, later in life, and even in succeeding generations.
• Progressive cell death from neurodegenerative causes
• Rapid cell death (as in stroke or traumatic brain injury), in which the circulatory system is interrupted or the brain is concussed or penetrated.
• Loss of neural function and connections
• Life stress, including inadequate developmental opportunities, poor nutrition, and PTSD.

Treating Behavioral Disorders

• Treatments for behavioral disorders do not have to be direct biological or medical interventions.
• Behavioral treatments focus on personal and environmental factors that influence behavior.
• Types of behavioral modification:
• Therapists apply principles developed in studies of learning by reinforcement conducted in laboratory settings, including operant and classical conditioning.
• Replace the maladaptive behaviors with more constructive ways of behaving.
• Systematic desensitization: training the individual to relax during systematic exposure.
• Cognitive Therapy: Operates from the perspective that thoughts intervene between events and emotions. Cognitive therapies challenge a person's self-defeating attitudes.
• Neuropsychological Therapy: Therapies for cognitive disorders resulting from brain trauma or dysfunction aim to retrain people in the fundamental cognitive processes they have lost and to exploit those that remain.
• Emotional Therapy: Talking about emotional problems enables people to gain insight and psychotherapies can serve as treatment.
• Physical Activity and Music as Therapy: Exercise and music have positive effects on attitudes, emotional well-being, and brain function.
• Real-Time fMRI: Individuals learn to change their behavior by controlling their own brain activation patterns; uses biofeedback; Thought of as neural plasticity
• Virtual Reality Therapy: Participants enter/interact with a virtual world displayed on a screen or through goggles.