Biological Bases of Psychological Disorders (7A) - Psych & Soc

Which option best matches the symptom type in schizophrenia: hallucinations and delusions are what type?

Positive symptoms. Added experiences (hallucinations/delusions) beyond normal function.
What is the diathesis-stress model of psychological disorders?

Disorder risk = predisposition plus environmental stressors. Combines genetic vulnerability with environmental triggers.
What is the key mechanism of typical (first-generation) antipsychotics?

D $_2$ receptor antagonism. Blocks dopamine D $_2$ receptors to reduce positive symptoms but may cause extrapyramidal side effects.
Which brain circuit is most associated with OCD pathophysiology?

Cortico-striato-thalamo-cortical (CSTC) loop. Dysfunction in this loop impairs inhibition of intrusive thoughts, central to OCD symptoms.
What does heritability ( $h^2$ ) represent in behavioral genetics?

Proportion of trait variance due to genetic differences in a population. Measures genetic contribution to phenotypic variation in populations.
What is gene-environment interaction in the context of psychological disorders?

Environmental effects on disorder risk depend on genotype (and vice versa). It describes how genetic factors moderate environmental impacts on psychopathology, or vice versa, influencing disorder manifestation.
What is the primary mechanism of selective serotonin reuptake inhibitors (SSRIs)?

Inhibit serotonin reuptake (block SERT) to increase synaptic 5-HT. Blocking the serotonin transporter prolongs neurotransmitter presence in the synapse, alleviating depressive symptoms.
Identify the hormone released by the adrenal cortex as the end product of HPA-axis activation.

Cortisol. HPA activation culminates in glucocorticoid release, mediating stress effects on brain and behavior.
Which neurotransmitter is most strongly linked to positive symptoms of schizophrenia?

Dopamine (especially increased mesolimbic activity). Hyperactive dopamine pathways cause hallucinations and delusions.
Which neurotransmitter is most associated with OCD in common MCAT frameworks?

Serotonin dysregulation. Altered serotonin signaling in frontostriatal circuits contributes to obsessive thoughts and compulsions.
Which neurotransmitter is classically linked to reward and is implicated in addiction?

Dopamine. Activates reward pathways; dysregulated in substance use disorders.
What is the core neurobiological mechanism of benzodiazepines?

Increase GABA-A receptor activity (greater Cl⁻ influx). Enhances inhibitory signaling by opening chloride channels.
What is the most common neuroimaging finding in major depressive disorder regarding the prefrontal cortex?

Decreased activity in prefrontal cortical regions. Hypoactivity impairs emotional regulation and executive function.
Which movement disorder is a common extrapyramidal side effect of antipsychotics (especially typical)?

Tardive dyskinesia. Long-term D $_2$ antagonism leads to involuntary movements due to dopamine receptor upregulation.
What is the primary mechanism of action of benzodiazepines in anxiety treatment?

Increase $GABA_A$ receptor activity (increase inhibitory signaling). Enhances GABA's inhibitory effect, reducing neural excitation.
What brain region degenerates in Parkinson disease to cause dopamine loss?

Substantia nigra pars compacta. Dopaminergic neurons die, causing movement disorders.
Which neurotransmitter is most associated with depression in the monoamine hypothesis?

Serotonin (also norepinephrine). The hypothesis posits low monoamine levels cause depressive symptoms, with serotonin and norepinephrine deficits central.
What is the monoamine hypothesis of depression?

Depression involves reduced 5-HT, NE, and/or DA signaling. Links depression to deficient serotonin, norepinephrine, or dopamine.
Which epigenetic mechanism typically decreases transcription by tightening chromatin?

DNA methylation. Methyl groups on DNA compact chromatin and silence genes.
Which study design most directly separates genetic from shared environmental effects?

Twin studies comparing monozygotic versus dizygotic concordance. MZ twins share 100% DNA; DZ share 50%, allowing genetic effect isolation.
What is the primary mechanism of benzodiazepines in treating anxiety?

Increase GABA $_A$ receptor activity (increase Cl $^-$ channel opening frequency). Allosteric modulation enhances GABA binding, promoting inhibition to reduce anxiety symptoms.
Which neurotransmitter is most associated with mood regulation and is targeted by SSRIs?

Serotonin (5-HT). Low serotonin linked to depression; SSRIs block its reuptake.
Which brain structure is most strongly associated with fear processing in phobias and PTSD?

Amygdala. Central to threat detection and fear response.
Which research design best estimates genetic influence by comparing MZ vs DZ twins?

Twin study. MZ twins share 100% DNA; DZ twins share 50%, allowing genetic estimation.
What structural brain finding is commonly associated with schizophrenia?

Enlarged ventricles with reduced cortical gray matter. Brain tissue loss leads to fluid-filled space expansion.
Which neurotransmitter is the primary inhibitory transmitter implicated in anxiety and targeted by benzodiazepines?

GABA. Reduced GABAergic inhibition heightens neural excitability, contributing to anxiety; benzodiazepines enhance it.
Which basal ganglia circuit is most implicated in OCD pathophysiology?

Cortico-striato-thalamo-cortical (CSTC) loop dysfunction. Hyperactive loop creates repetitive thoughts and behaviors.
Which neurotransmitter is the primary excitatory transmitter and is implicated in schizophrenia hypotheses?

Glutamate. NMDA receptor hypofunction may contribute to psychotic symptoms.
What is the HPA axis outcome that is commonly elevated with chronic stress-related disorders?

Increased cortisol secretion. HPA axis hyperactivity releases excess stress hormone.
What is the diathesis-stress model of psychological disorders?

Disorder risk = predisposition (diathesis) + environmental stressors. Vulnerability plus stress triggers disorder onset.
Which option best describes the monoamine hypothesis of depression?

Depression relates to reduced monoamine signaling (5-HT, NE, DA). Deficient serotonin/norepinephrine/dopamine causes depressive symptoms.
What is epigenetics in the context of psychological disorders?

Environment-driven changes in gene expression without DNA change. Heritable changes in gene activity without altering DNA sequence.
Which brain structure is often hyperactive in anxiety disorders and phobias?

Amygdala. Fear center shows increased activity during threat processing.
Which sleep abnormality is classically associated with major depressive disorder?

Shortened REM latency (earlier onset of REM sleep). REM occurs sooner after sleep onset in depressed patients.
Which brain region is central for episodic memory and is often reduced in chronic PTSD or depression?

Hippocampus. Stress hormones can damage this memory-forming structure.
What is the genetic mutation pattern that causes Huntington disease?

Autosomal dominant CAG trinucleotide repeat expansion. HTT gene mutation; >40 repeats causes disease.
Identify the neurotransmitter change most consistent with the dopamine hypothesis of schizophrenia.

Increased dopaminergic signaling (especially mesolimbic). Excess dopamine activity linked to positive symptoms.
What is the core neurobiological mechanism of typical (first-generation) antipsychotics?

D $_2$ receptor antagonism (dopamine blockade). Blocks dopamine receptors, reducing positive symptoms.
What HPA-axis pattern is commonly associated with major depressive disorder?

Hyperactive HPA axis with elevated cortisol. Chronic stress causes persistent cortisol elevation.
Which neurotransmitter is most associated with alertness and is implicated in anxiety arousal?

Norepinephrine. Part of fight-or-flight response; elevated in anxiety states.
Which neurotransmitter is most associated with reward pathways and positive symptoms of schizophrenia?

Dopamine. Hyperactivity causes hallucinations; hypoactivity causes anhedonia.
Which neurotransmitter is most associated with mood regulation and SSRI treatment targets?

Serotonin. Low levels linked to depression; SSRIs block its reuptake.
What does "heritability" mean in behavioral genetics of mental disorders?

Population variance fraction attributable to genetic differences. Measures genetic contribution to trait variation in a population.
What is the diathesis-stress model of psychological disorders?

Disorder risk = predisposition (diathesis) + environmental stress. This model explains how genetic vulnerabilities interact with stressors to precipitate disorders, emphasizing multifactorial causation.
Which neurotransmitter is classically linked to schizophrenia via the dopamine hypothesis?

Dopamine. Excess dopamine activity in certain pathways contributes to hallucinations and delusions in schizophrenia.
What two protein pathologies are characteristic of Alzheimer disease?

Beta-amyloid plaques and hyperphosphorylated tau tangles. Plaques form between neurons; tangles form inside neurons.
What neurotransmitter abnormality is most associated with Huntington disease?

Decreased GABA (and decreased acetylcholine) in the striatum. Loss of inhibitory control causes involuntary movements.
What is epigenetics as it relates to psychological disorders?

Environment-driven changes in gene expression without DNA sequence change. Modifies gene activity through mechanisms like methylation, linking early life stress to long-term disorder susceptibility without altering DNA.
Which mood disorder is strongly linked to decreased serotonin and increased HPA-axis activity?

Major depressive disorder. Low serotonin impairs mood regulation, while HPA hyperactivity elevates stress hormones, exacerbating symptoms.
Which brain region is critical for forming new declarative memories and is stress-sensitive via cortisol?

Hippocampus. Chronic cortisol exposure can cause hippocampal atrophy.
Which finding supports a genetic contribution: higher concordance in MZ than DZ twins?

Genetic factors contribute to the disorder. MZ twins share more genes, so higher concordance suggests genetic influence.
What is the primary mechanism of serotonin-norepinephrine reuptake inhibitors (SNRIs)?

Inhibit reuptake of serotonin and norepinephrine (block SERT and NET). Dual inhibition elevates both neurotransmitters in synapses, effective for depression resistant to SSRIs.
Which neurotransmitter is the primary inhibitory transmitter and is targeted by benzodiazepines?

GABA. Reduces neural excitability; enhanced by anti-anxiety drugs.
Which dopamine pathway hypoactivity is most associated with negative symptoms of schizophrenia?

Mesocortical pathway. Underactivity in this prefrontal pathway contributes to cognitive deficits and emotional blunting in schizophrenia.
Which neurotransmitter is most strongly linked to depression in the monoamine hypothesis?

Decreased serotonin (often with decreased norepinephrine). Monoamine hypothesis: low 5-HT (and NE) causes depressive symptoms.
Which neurotransmitter is most directly associated with anxiolysis via increased inhibition?

GABA. Primary inhibitory neurotransmitter; benzodiazepines enhance GABA.
What is the key limitation of heritability estimates for individuals?

They do not predict an individual's risk; they apply to populations. Heritability describes population variance, not individual genetic risk.
What neurotransmitter deficit is classically associated with Parkinson disease?

Decreased dopamine in the nigrostriatal pathway. Loss of DA neurons causes motor symptoms (tremor, rigidity).
What is the primary mechanism of benzodiazepines for acute anxiety?

Increase GABA $_A$ receptor activity (positive allosteric modulators). Enhance GABA's inhibitory effects at receptors.
Which neurotransmitter abnormality is classically linked to OCD in MCAT frameworks?

Serotonin dysregulation (often conceptualized as decreased 5-HT). SSRIs treat OCD by increasing serotonin availability.
Which dopamine pathway hyperactivity is most associated with positive symptoms of schizophrenia?

Mesolimbic pathway. Overactivity in this reward-related pathway underlies positive symptoms like paranoia and auditory hallucinations.
What neurotransmitter deficit is classically associated with Alzheimer disease?

Decreased acetylcholine (cholinergic deficit). ACh-producing neurons degenerate, especially in the basal forebrain.
Identify the HPA-axis hormone that is commonly elevated with chronic stress.

Cortisol. Primary stress hormone released by adrenal cortex.
What is the HPA axis response pattern commonly associated with chronic stress and depression?

Hyperactive HPA axis with elevated cortisol. Chronic stress dysregulates hypothalamic-pituitary-adrenal feedback.
What is the primary mechanism of SNRIs in depression treatment?

Inhibit serotonin and norepinephrine reuptake. Dual action blocks both SERT and NET transporters.
Which neurotransmitter is classically increased at the synapse by SSRIs to treat depression and anxiety?

Serotonin ( $5$ -HT). SSRIs block reuptake, increasing synaptic serotonin levels.
What is the diathesis–stress model of psychological disorders?

Disorder risk = predisposition (diathesis) + environmental stressors. Combines genetic vulnerability with life stress to explain disorder onset.
What is the core biological feature that distinguishes delirium from dementia?

Delirium is acute and fluctuating; dementia is chronic and progressive. Delirium develops rapidly with attention deficits; dementia develops slowly with memory loss.
Which brain region is commonly hyperactive in anxiety disorders and fear conditioning?

Amygdala. Processes emotional threats, with hyperactivity leading to exaggerated fear responses in anxiety.
What is epigenetics as it relates to psychological disorders?

Environmental effects on gene expression without changing DNA sequence. Modifies gene activity via methylation/histones, not mutations.
Which brain region supports executive control and is often hypoactive in ADHD?

Prefrontal cortex. Regulates attention, planning, and impulse control.
Which disorder is most associated with reduced hippocampal volume after chronic stress exposure?

Posttraumatic stress disorder (PTSD). Chronic stress in PTSD atrophies the hippocampus, impairing memory consolidation and fear extinction.
What is epigenetics in the context of psychological disorders?

Environment-driven changes in gene expression without DNA sequence change. Stress/trauma can alter gene activity via methylation/histones.
Which study design best separates genetic effects from shared environment by studying adoptees?

Adoption study (biological vs adoptive relatives). Compares adoptee traits to biological vs adoptive parents.
What is the primary mechanism of SSRIs in depression treatment?

Inhibit serotonin reuptake, increasing synaptic 5-HT. Blocks SERT transporter, keeping serotonin in synapse longer.
Which study design most directly estimates genetic influence by comparing MZ vs DZ twins?

Twin study (MZ vs DZ concordance comparison). MZ twins share 100% genes; DZ share 50%, revealing genetic effects.
Which brain region classically shows reduced volume in major depressive disorder?

Hippocampus. Stress and depression cause hippocampal atrophy.
What does heritability mean in behavioral genetics?

Proportion of trait variance in a population due to genetic variation. It quantifies the genetic contribution to phenotypic differences, estimated via twin and adoption studies.
Identify the hormone released from the adrenal cortex as the end-product of HPA axis activation.

Cortisol. Primary stress hormone; chronically elevated in depression.
Which brain region is most associated with executive control and impulse regulation?

Prefrontal cortex. Top-down control center for planning and inhibiting behaviors.
What is the core pharmacologic action of typical antipsychotics?

D $2$ receptor antagonism (dopamine blockade). Blocks dopamine receptors to reduce positive symptoms.
Which option best reflects gene–environment interaction (G $\times$ E) in psychopathology?

Genetic risk alters sensitivity to environmental stressors. Genes modify how individuals respond to environmental factors.
Which neurotransmitter is most associated with inhibitory signaling and anxiety reduction (target of benzodiazepines)?

GABA. Primary inhibitory NT; benzos enhance its calming effects.
What is meant by heritability in behavioral genetics?

Proportion of trait variance in a population due to genetic differences. Measures genetic contribution to population variation, not individual traits.
Which brain region is most associated with fear conditioning and is hyperactive in many anxiety disorders?

Amygdala. Processes threat detection and emotional salience.
Which brain structure shows reduced volume most classically associated with PTSD and chronic stress exposure?

Hippocampus. Stress hormones damage hippocampal neurons over time.
Which brain region supports executive control and is often hypoactive in depression and ADHD?

Prefrontal cortex. Reduced activity impairs planning, focus, and emotional regulation.
Which neurotransmitter is most associated with excitatory signaling and NMDA receptor hypotheses in schizophrenia?

Glutamate. Primary excitatory NT; hypofunction may contribute to psychosis.
What does heritability estimate in behavioral genetics represent?

Proportion of trait variance in a population due to genetic variation. Measures how much genes (vs environment) contribute to individual differences.
Which endocrine axis is commonly dysregulated in major depressive disorder and chronic stress?

HPA axis (hypothalamic-pituitary-adrenal axis). Overactive in depression, causing elevated cortisol levels.
Which dopamine pathway is most linked to positive symptoms of schizophrenia?

Mesolimbic pathway hyperactivity. Overactive reward pathway causes hallucinations and delusions.
Which brain region is most associated with fear conditioning and threat detection?

Amygdala. Processes emotional salience and triggers fear responses.
What is the core neurobiological mechanism of SSRIs?

Inhibit serotonin reuptake, increasing synaptic 5-HT. Blocks SERT transporter, prolonging serotonin's synaptic action.
What is the key limitation of twin studies that can inflate genetic estimates?

Equal environments assumption may be violated. MZ twins may be treated more similarly than DZ twins.
What is the core neurobiological mechanism of lithium in bipolar disorder (high-level description)?

Mood stabilizer that modulates intracellular signaling (e.g., second messengers). Affects multiple pathways including GSK-3 and inositol systems.
What is the primary mechanism of monoamine oxidase inhibitors (MAOIs)?

Inhibit monoamine oxidase, decreasing breakdown of 5-HT, NE, and DA. Prevents enzymatic degradation of monoamines, increasing their availability for mood regulation.
What neurotransmitter abnormality is most associated with schizophrenia?

Increased dopamine signaling (especially mesolimbic pathway). Dopamine hypothesis: excess DA activity causes psychotic symptoms.
Which neurotransmitter system is classically implicated in anxiety disorders?

GABA (reduced inhibitory signaling is associated with anxiety). Primary inhibitory neurotransmitter; deficiency increases anxiety.
What is concordance in the context of twin studies of psychological disorders?

Probability both twins show the same trait or disorder. If one twin has disorder, concordance = chance the other does too.
Which neurotransmitter is classically reduced in depression and is targeted by SNRIs and TCAs?

Norepinephrine. Low NE linked to mood/energy; SNRIs block its reuptake.
Which research design most directly separates genetic from shared environmental effects: twin or cross-sectional?

Twin study. Compares monozygotic and dizygotic twins to isolate genetic influences while controlling for shared environments.
What does HPA axis stand for in stress-related disorder physiology?

Hypothalamic-pituitary-adrenal axis. Regulates stress response, with dysregulation linked to disorders like PTSD and depression.
Which neurotransmitter is classically linked to reward, motivation, and positive symptoms of schizophrenia?

Dopamine. Excess dopamine activity linked to hallucinations/delusions.
Which brain structure is most associated with fear processing and is often hyperactive in anxiety disorders?

Amygdala. Overactivation triggers fear responses and anxiety symptoms.
Which medication class blocks $D_2$ receptors and is used to treat psychosis?

Antipsychotics (dopamine $D_2$ receptor antagonists). Blocking dopamine receptors reduces hallucinations/delusions.
Which dopamine pathway dysfunction is most linked to negative symptoms of schizophrenia?

Mesocortical pathway hypoactivity. Reduced frontal DA causes flat affect and avolition.
Which neurotransmitter deficit is most associated with Alzheimer disease and impaired memory?

Acetylcholine deficiency. Cholinergic neurons degenerate, impairing memory formation.
What is the classic structural brain finding associated with schizophrenia?

Enlarged ventricles (often with cortical volume loss). Reflects neurodegeneration and gray matter loss.
What is the best-known neurotrophic factor linked to depression via neuroplasticity?

BDNF (brain-derived neurotrophic factor). Promotes neuronal growth and plasticity; reduced in depression.
Which statement best describes heritability as used in biological bases of disorders?

Proportion of trait variance in a population due to genetic variation. Heritability = genetic variance/total variance (ranges 0-1).
Which brain region shows early prominent atrophy in Alzheimer disease?

Hippocampus (medial temporal lobe). Memory formation center shows early degeneration.
Which neurotransmitter is most associated with alertness and arousal and is targeted by SNRIs?

Norepinephrine. Part of fight-or-flight response; dysregulated in anxiety/depression.
Which term describes one gene influencing multiple traits, potentially linking a gene to several disorders?

Pleiotropy. Single gene affects multiple phenotypes simultaneously.
Which sleep stage abnormality is classically associated with major depressive disorder?

Decreased REM latency with increased REM density. REM occurs earlier and more intensely in depression.
What is the primary mechanism of MAO inhibitors (MAOIs)?

Inhibit monoamine breakdown, increasing 5-HT, NE, and DA. Prevents enzymatic breakdown of monoamines.
What is the key receptor profile of atypical (second-generation) antipsychotics?

5-HT $_2$ antagonism with weaker D $_2$ antagonism. Targets serotonin 5-HT $_2$ receptors primarily, with less D $_2$ blockade, reducing negative symptoms and extrapyramidal effects.
What is the primary mechanism of action of SSRIs?

Inhibit serotonin reuptake transporter to increase synaptic $5$ -HT. Blocks SERT protein, preventing serotonin removal from synapse.

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