Ch. 15 - addiction, developmental, anxiety, and depressive disorders

Neuropsychiatric disorders exist…

On a spectrum

Disorders have influence from…

Genetic, epigenetic, and environmental factors

Much is still not…

Known about neuropsychiatric disorders, especially medication

Many neuropsychiatric disorder share…

Symptoms, causes, and genetics

Neuropsychiatric diagnoses can be…

Stigmatizing

Substance use disorder (addiction)

A pattern of compulsive behaviors such as drug taking or gambling

Measured by degree of harm it causes to the individual and those around them

Comes with social stigma

SUD: risk factors

adolescence and emerging adults, other disorders (anxiety, depression, personality disorders, PTSD), early trauma, stressful environment

SUD: negative reinforcement theory

take drugs to counteract withdrawal or negative statE

SUD: problems with negative reinforcement theory

some highly addictive drugs don’t cause severe withdrawal, relapse long after withdrawal symptoms, some drugs don’t promote addiction but do cause withdrawal

SUD: positive reinforcement theory

take drugs because they produce euphoric pleasurE

SUD: problems with positive reinforcement theory

euphoria goes away, some addictive drugs don’t cause euphoria, destruction of addiction outweighs pleasure

SUD: Incentive-Sensitization Theory

the MTDS becomes sensitized to drugs and stimuli

MTDS is activated, it creates strong craving

Classical conditioning

Instrumental conditioning of increased craving when stimuli are present, dorsal striatum plays large role

Even visual/environmental cues can trigger cravings

Sensitization is long lasting

SUD A&P: Mesotelencephalic Dopamine System (MTDS)

ventral tegmentum sends signals to the nucleus accumbens

Activated by addictive drugs, stimuli associated with drugs, and anticipation of reward (activated most when uncertainty about the reward)

Cravings (lead to relief not enjoyment of substance use)

SUD A&P: CREB

habituation and tolerance

Increase with NA in drug taking

Activated gene that produces dynorphin which reduced pleasurable feelings and causes increased dosage

SUD A&P: ΔFosB

causes sensation of cravings

Released when drug taking

Long lasting (after stopping drugs) so it influences relapse

Increases BDNF

Facilitates learning - increased learned behaviors surrounding substances so there is an increased risk of relapse or additional addiction

Autism Spectrum Disorder

difficulty with social interaction and communication, hypersensitive to stimuli, repetitive behavior, need for routine

ASD: Risk Factors

genetics, exposure to heavy metals, pesticide, herbicides, other disorders (down syndrome, fragile x, PKU), NOT vaccines

ASD and the Brain

NA reacts differently to rewards

Over activation of amygdala and PFC

Makes stimuli overwhelming

ASD: treatment

ABA, not many medications (maybe vasopressin and oxytocin)

Attention Deficit Hyperactivity Disorder

difficulty with executive functioning, focusing, paying attention, and regulating and controlling behaviors

Presentations: hyperactive (boys), inattentive, combined

ADHD: risk factors

boys (3x more likely), other disorders (ASD, anxiety, epilepsy), genetics, TBI, exposure to chemicals

ADHD and the Brain

under activation of PFC parietal lobes, limbic system, and striatum

Areas that control attention, inhibit unwanted stimuli, and are high in dopamine neurons

ADHD: treatment

psychostimulants, psychotherapy

Major Depressive Disorder

anhedonia, hopelessness, helplessness, worthlessness

Affects sleep, sex, appetite

Common disorder, twice as likely in women than men

Presents as anger or irritability in men (?)

Linked to anxiety, SUD, cardiovascular disease, suicide

It is normal to experience SOME depression

Depression treatments

MAOI’s, SSRI’s, SNRI’s, tricyclic antidepressants, CBT, ECT, tDCS, DBS

Depression: Monoamine hypothesis

Chronically low levels of monoamines (serotonin, norepinephrine)

Depression: monoamine oxidase inhibitors

Decrease monoamine oxidase, the enzyme that breaks up monoamines

Antidepressants are monoamine agonists

Depression: MAOI’s cheese reaction

side effect of eating certain foods (cheese, meat, red wine) which cause high BP

Depression: tricyclic antidepressants

Serotonin and Norepinephrine reuptake inhibitors

Not used as often anymore, can be fatal in high doses

Depression: selective serotonin reuptake inhibitors

most common, keeps serotonin in synapse, may restructure transporters and g-proteins

Prozac, zoloft, paxil

Depression: Norepinephrine reuptake inhibitors

keeps norepinephrine in the synapse

Depression: problems with antidepressants

Take a long time to work and for many, dont work at all

Depression: cognitive behavioral therapy

learn to recognize and replace negative thoughts or behaviors, medication and CBT is more effective

Depression: electroconvulsive therapy

given anesthetic and muscle relaxants, electrical currents are fired across brain

Patients don’t remember and offers fast relief of treatment resistant depression

Depression: transcranial direct current stimulation

reduced amps compared to ECT, mild forms of depression

Depression: deep brain stimulation

electrodes implanted into brain, level of electricity is controllable, used for treatment resistant MDD, mixed results

Bipolar disorder 1

mania, high risk of suicide or SIB

Bipolar disorder 2

hypomanic and depressive episodes, more functional

Bipolar disorder

depression with bouts of mania

Mania

extreme energy, irrational behavior, thoughts, delusions, sometimes hallucinations

Hypomania

less extreme than mania, fewer irrational thoughts and behaviors, more functional

Bipolar: treatment

mood stabilizers and therapy

Panic disorder

sudden feelings of fear and stress (panic attack) and fear of a future panic attack

Overactivation of SNS, amygdala, and PAG

Could be product of pH imbalance in brain

Obsessive-compulsive disorder

frequent, uncontrollable, anxiety producing thoughts, repetitive or ritualistic behaviors

Handwashing, checking locks/stove, counting

Increased activity in frontal cortex, striatum, cingulate cortex, and basal ganglia

Genetics? Infections? PANDAS?

Post-traumatic Stress Disorder

following extremely stressful event, problems with sleep, memory, intrusive thoughts, flashbacks

Self-destructive behaviors, depression

TBI, low activity of cortisol in response to stressors

Anxiety: treatment

Anxiolytics, benzodiazepine, antidepressants

Anxiety: benzodiazepine

prescribed anxiolytics, GABA agonists, addictive, can lead to overdose, stopping can heighten anxiety

Prescribed PRN (as needed)