Psychological Disorders | Psychology and Sociology for MCAT PDF Download

Introduction to Psychological Disorders

• Psychological disorders are a characteristic set of feelings, thoughts, or behaviors that differ from the cultural norm and can cause distress to the individual suffering from them.
• The Diagnostic and Statistical Manual of Mental Disorders (DSM) is a standardized resource used to assist clinicians in classifying and diagnosing these disorders. There are 20 different classes of psychological disorders defined by the DSM. In recent decades, we have learned a great amount about the physiology of these disorders and are able to classify them with increasing specificity. Within this guide, we’ll go over several key types of psychological disorders, their biological basis, and much more.
• It may also be helpful to keep in mind the biomedical and biopsychosocial approaches to treatment. These are frameworks, or perspectives, used to guide professional therapies and treatment for a psychological disorder.
• The biomedical approach views the root of these disorders as a physiological imbalance or disturbance. If this is true, then the method of treatment should also be biomedical in nature, aiming to reduce the symptoms of the disorder through a strictly scientific, neurochemical approach. This is a much more narrow scope of approach than the biopsychosocial approach because this approach fails to focus on additional stressors and factors in an individual’s life that may contribute to or exacerbate the disorder. For instance, an anxiety disorder could be due to neurotransmitter imbalance within emotional regions of the brain (a biomedical explanation) but could also be due to patterns of neglect in a family (an environmental factor). 
• The biopsychosocial approach is a more holistic view of psychological disorders. This approach considers biomedical, psychological, and social factors when considering stressors that may exacerbate the disorder. As you may have presumed, biomedical factors refer to an individual’s physiology; psychological factors refer to their thoughts and emotions; and social factors come from environmental, societal factors that are beyond the individual’s control.  Under this framework, biopsychosocial treatment may combine direct therapy with a patient (such as prescribing medication or through one-on-one therapeutic sessions) and indirect therapy, which provides support for the individual with help from family, friends, or other components of the individual’s social network.

Psychotic, Depressive, and Related Disorders

Many psychological disorders appear to be somewhat hereditary or genetic. We will first address some of these disorders, starting with the psychotic disorders.

(a) Schizophrenia

• Individuals who suffer from psychotic disorders suffer from psychosis. Psychosis can manifest in feelings of paranoia, delusions, hallucinations, and a general loss of reality. 
• While the DSM lists several forms of psychotic disorders, the MCAT will focus on schizophrenia as the representative psychotic disorder. Schizophrenia is characterized by the presence of several positive symptoms that characterize psychosis, along with negative symptoms that further illustrate a deviation from normal behavior. 
• The prodromal phase, or prodrome, is a period of time directly before a diagnosis of schizophrenia. As this phase is primarily characterized by an abrupt change in behavior, family members and friends may notice “odd” behavior for a period of weeks or months, including a withdrawal from typical social activities and mood swings. The end of prodrome is marked by the onset of positive and negative symptoms of schizophrenia.
• Positive symptoms refer to behaviors or thoughts that are exhibited in addition to an individual’s normal behavior, such as delusions, hallucinations, or nervous tics.
• Positive symptoms come in many shapes and sizes. These behaviors are considered “symptoms” because they differ from the social norm of the culture in which they are observed. Hallucinations or delusions, for example, are considered commonplace in some Caribbean cultures as part of rituals, but in western culture, these may seem like symptoms. 
• Hallucinations are false observations that are not based on reality but are perceived as such. These can be auditory, like voices in someone’s head, or visual, like seeing a dead relative. Auditory hallucinations are more common than visual. 
• Delusions are held beliefs that directly contradict what is observed in reality. Delusions are usually firmly held onto by an individual and are generally not shared with multiple people. 
• Individuals may also begin to exhibit disorganized thoughts and behaviors. Patients with disorganized thought may be unable to express a cohesive narrative in conversation and instead express haphazard thoughts. Word salad is an extreme example of this, when the expressed thoughts are simply random words strung together. Disorganized behaviors follow a similar theme and refer to when an individual is unable to carry out their normal routine.
• Negative symptoms refer to the lack or absence of an individual’s normal behavior, like the inability to eat or lack of emotion (or lack of affect). Affect refers to the display and conveying of emotion. Someone with flat affect displays virtually no emotion at all, while someone with inappropriate affect displays affect that is discordant with the individual’s speech or behavior. 
• Schizophrenia is also often associated with the downward drift hypothesis, stating that the symptoms of schizophrenia can lead to a decline in social wealth and resources, putting the individual at greater risk for experiencing worsening social factors and increasing the intensity of symptoms. This leads to a vicious cycle of worsening schizophrenia and socioeconomic status. 
• Based on genetic studies, the onset of schizophrenia seems to have a high hereditary factor. On a neurotransmitter level, individuals with schizophrenia appear to have elevated levels of dopamine in the brain. Neuroleptics (dopamine receptor antagonists) are used to treat schizophrenia.

(b) Depressive Disorders
While mood swings and natural sadness may last for hours or days, depressive disorders are characterized by an abnormally long period of sadness or intense feeling. Major depressive disorder is a mood disorder and is characterized by at least one major depressive episode. To be diagnosed with a major depressive episode, the patient must experience feelings of depression or sadness for at least two weeks and experience at least five symptoms from the following list:

• low or depressed mood
• anhedonia (loss of interest in previously interesting activities)
• changes in appetite and weight gain or loss
• sleep disturbances
• persistent feelings of guilt 
• difficulty concentrating
• thoughts of death or suicide
• decreased energy in day-to-day activity

Depression is highly associated with an overactive amygdala: a small structure within the brain that controls basal emotions, such as fear and anxiety. The monoamine theory of depression describes a key physiological feature associated with depression: decreased levels of the neurotransmitters serotonin, dopamine, and norepinephrine levels.
Patients who experience depressed mood that is not severe enough to be diagnosed as a major depressive disorder may be diagnosed with dysthymia. Dysthymia is often diagnosed in individuals who experience a depressed and low mood for at least 2 years but who do not experience other symptoms of major depressive disorder.
Seasonal affective disorder (SAD) is not an isolated diagnosis in the DSM. Individuals who do not experience major depressive disorder or dysthymia may still experience a persistent depressive mood during the winter months. It is hypothesized that the lack of sunlight during the winter causes disruptions in melatonin metabolism, thereby affecting mood. As a result, bright light therapy is typically prescribed as a therapeutic method.

(c) Bipolar Disorders 

• Bipolar disorders are characterized by some combination of manic episodes (or hypomania) and depressive episodes. 
• Manic episodes are periods characterized by intensely high energy, high productivity, decreased need for sleep, and/or thoughts of grandeur. These episodes of elevated mood must last more than one week. Similarly, hypomania is an increased level of excitability; however, it is distinguished from mania as it does not inhibit the individual’s normal routines to the same degree. Depressive episodes will manifest similarly to the symptoms listed in the depressive disorders, with periods of persistent low mood and anhedonia. 
• There are three forms of bipolar disorder, each characterized by manic and depressive episodes occurring to differing degrees.
  • A diagnosis of bipolar I disorder requires documented manic episodes but may or may not require depressive episodes.
  • A diagnosis of bipolar II disorder requires documented hypomania, with at least one major depressive episode.
  • A diagnosis of cyclothymia requires a combination of hypomanic episodes and periods of dysthymia. Note that these periods of hypomania and dysthymia do not need to be as intense as periods of mania or depression.
• Bipolar I disorder, bipolar II disorder, and cyclothymia all involve differing degrees of mania and depression.
• The monoamine/catecholamine theory of depression explains the origin of mania and depression from a neurological transmitter. Under this theory, an overabundance or paucity of norepinephrine and serotonin leads to mania and depression, respectively.

(d) Personality disorders

• Personality disorders manifest in behavior patterns that appear to be erratic or strange by cultural standards. These disorders tend to warp the individual’s emotions, interpersonal functioning, and cognition in a way that results in impulsive actions and faulty explanations. Importantly, individuals with personality disorders tend to consider their behaviors and thoughts to be completely normal! They do not necessarily recognize these erratic thoughts and behaviors as abnormal or distressing. 
• While there are many subtypes of personality disorders, they are generally clustered into three overlapping groups. For the MCAT, it will be sufficient to distinguish disorders as belonging to Cluster A, Cluster B, or Cluster C. 
• Cluster A disorders include paranoid, schizotypal, and schizoid personality disorders. Paranoid personality disorder leads individuals to have a very strong distrust of others and their motives. Schizotypal personality disorders are characterized by eccentric thinking unaccepted by the cultural norm. Schizoid personality disorder applies to individuals who are disinterested in or detached from personal relationships with others. This cluster may be well-remembered as the “weird” disorders.
• Cluster B disorders include antisocial, borderline, histrionic, and narcissistic personality disorders. Antisocial personality disorder is marked by a disregard for the rights, emotions, or desires of others. It has also come to be known as sociopathy and is characterized by a lack of remorse for one’s actions. Borderline personality disorder is marked by instability in mood, interpersonal relationships, self-esteem, and behavior and tends to be diagnosed more often in females. Histrionic personality disorder is marked by high amounts of attention-seeking behavior, particularly through seductive actions or wearing colorful clothing. Narcissistic personality disorder applies to individuals with exaggerated demands for attention and reinforcement of self-esteem. This cluster may be well-remembered as the “wild” disorders.
• Cluster C disorders include disorders that lead to activities others might deem anxious or fearful. Avoidant personality disorder is characterized by an incredible fear of rejection. Individuals with avoidant personality disorder may isolate themselves from social situations even though they long for interaction to avoid failure and rejection. Dependent personality disorder is marked by a constant need for reassurance and comfort from others. Individuals with dependent personality disorder are unable to act on their own and are very codependent. Individuals with obsessive-compulsive personality disorder appear to have a strict need for order and neatness; they do not like to change their minds or routines and are very stubborn. (Note that this is not the same disorder as obsessive-compulsive disorder, which is discussed below.) This cluster may be well-remembered as the “worried” disorders.

(e) Somatic Symptom Disorders

• While the psychological disorders we have discussed occasionally result in erratic behavior, it is often the case that individuals do not notice abnormalities in behavior or do not consider them to be abnormal. In contrast, somatic symptom disorder is typically diagnosed when an individual has a somatic symptom—such as abnormal physical signs or sensory deficit—that is not necessarily caused by another medical condition or physiological abnormality. For instance, an individual may have chronically shaking hands, but all test results and scans indicate that the shaking is not due to a neurological condition. 
• Conversion disorder is similar to somatic symptom disorder in that individuals present with an unexplained somatic symptom. However, these symptoms typically follow traumatic events, such as feeling numbness in an arm after watching someone else lose a limb—though the muscles of the arm and the motor neurons have no noticeable injuries.
• Illness anxiety disorder refers to when a person is consumed with the thought of having an illness or disease. Individuals with an illness anxiety disorder may frequent hospitals and health clinics and excessively request medical exams out of concern that they may have various medical conditions.

Behavioral and Related Disorders

Several psychological disorders—including obsessive-compulsive disorder, post-traumatic stress disorder, and dissociative disorders—may be induced by an environmental cause or past event in an individual’s life. Treatment for these disorders often includes cognitive-behavioral therapy (CBT). During CBT, a therapist or trained medical professional works with the patient to investigate the patterns of negative thinking or reevaluate trigger events that may have led to the disorder.
CBT can be used in conjunction with medication but is primarily used to re-shape the behavior or pattern of thinking at the root of a psychological diagnosis. As CBT is used to evaluate the health and well-being of the patient as a whole, the therapist may also involve the patient’s support system (e.g., family, friends, or coworkers) to create a supportive environment and eliminate stressors.

(a) Obsessive-Compulsive Disorder

• Obsessive-compulsive disorder is characterized by obsessions and compulsions. Obsessions are thoughts that repeatedly return to the individual and are repetitive to the point of detriment.
• Compulsions are behaviors that relieve the tension caused by the obsession. These compulsions might be repeatedly returning to the door to ensure that it is locked or hand-washing multiple times—to relieve obsessions such as worrying whether the door is unlocked or hyperawareness of dirt on the body.

(b) Body Dysmorphic and Eating Disorders

• A person with body dysmorphic disorder holds an exceedingly negative perception of their appearance—a belief that deeply impacts their self-esteem and disrupts daily routines. While many of us may hold negative opinions about our bodies, such as thinking that we have a large nose or may need to lose a few pounds after the holidays, body dysmorphia only applies when these perceptions are preoccupations that disrupt day-to-day life. 
• Anorexia nervosa is a body-weight disorder in which individuals are overly concerned with being thin. These individuals may severely restrict their calorie intake, engage in extreme amounts of exercise, and/or binge and purge. Binging and purging refers to a cycle of eating large quantities of food (binging) and subsequently self-inducing vomiting to expel the food that was eaten (purging). These individuals are typically very thin and have a dangerously low body mass index (BMI). Despite their physical appearance, they may have a desire to become increasingly thinner.
• Bulimia is a similar body-weight disorder to anorexia. Individuals are similarly concerned with being thin and may engage in the same patterns of binging and purging. However, these individuals typically appear to be of healthy body weight and have a normal body mass index (BMI). 

(c) Post-Traumatic Stress Disorder

• Post-traumatic stress disorder (PTSD) occurs after experiencing a traumatic event such as war, death, or other tragedies. Individuals who suffer from this disorder experience a characteristic cycle of experiencing intrusive thoughts, exhibiting avoidance behaviors, and displaying physiological arousal symptoms. 
• Intrusive thoughts cause the individual to “relive” the event. Interactions with the environment or in the individual’s daily life may trigger the individual to believe that they are experiencing prior traumatic experiences again. When experiencing these thoughts, patients will struggle to return to reality—even though they may understand that they are not reliving past experiences. 
• Avoidance symptoms are attempts to avoid similar situations or triggers that can lead to PTSD episodes: including explicit removal of memories or avoidance of subject matter that may lead to further intrusive thoughts.
• Arousal symptoms are often also present but do not need to occur concurrently with intrusive thoughts or avoidance symptoms. These manifest as stimulations of the sympathetic nervous system and result in symptoms similar to irritability, anxiety, and a lack of sleep.

(d) Anxiety Disorders

• Anxiety disorders come in many forms. Generalized anxiety disorder is very common and refers to a persistent worry about many different environmental stressors. Symptoms of generalized anxiety can present as fatigue, muscle tension, and sleep problems.
• Specific phobias are irrational fears that are associated with specific objects or situations, such as spiders (arachnophobia) or the fear of enclosed spaces with no escape (agoraphobia). 
• Social anxiety disorder refers to anxiety in social situations that could lead to embarrassment. While it is normal and healthy for individuals to fear embarrassment when performing in a school play or asking questions in class, a social anxiety disorder can prevent individuals from acting in everyday, low-stress situations, such as ordering food at a restaurant or checking out at a grocery store.
• Panic disorder consists of repeated panic attacks, characterized by fear, sweating, and hyperventilation. Panic attacks are no joke! People who experience them actually feel like they are in immediate danger. Panic attacks heavily activate the sympathetic nervous system, activating the “fight or flight” instinct in response to some environmental stimulus.

(e) Dissociative Disorders

• Dissociative disorders are marked by an apparent “escape from reality” to avoid stressors in the environment. While individuals with dissociative disorders still have an understanding and grasp of reality, they tend to distance themselves from stress in a unique manner. 
• Dissociative amnesia leads to a breakdown of memories of past events. Here, patients will dissociate themselves from reality by presenting with amnesia that is not due to any underlying neurological conditions. 
• Dissociative fugue refers to a sudden departure from normal daily activities. An individual in dissociative fugue may even forget who they are or assume a new identity, with no recollection of their “past” life.
• Dissociative identity disorder (DID), formerly known as “multiple personality disorder,” refers to the apparent existence of two or more distinct identities within a single individual. These personalities may “compete” for control within an individual, resulting in a single person exhibiting markedly different personalities, personal histories, and mannerisms.
• Depersonalization is when an individual feels separated from their own mind and body—as in an “out of body experience.”  Derealization is when an individual feels separated from their surroundings, and the world appears dreamlike. Individuals who experience depersonalization or derealization may even feel as if they are watching a facsimile of themselves move through a fictional world. Importantly, they do not seem to experience delusions or hallucinations.
• Dissociative disorders are a very controversial group of psychological disorders, namely because scientific studies about dissociative disorders rely on the testimony of patients, and it is difficult to verify these testimonies. Further, diagnosis of dissociative disorders seems to be associated with cultural influences of the time, for instance, high-profile murder cases in which the murderer professes to have DID or television shows with DID patients. It is unclear whether DID is a genuine psychological disorder that requires treatment or is a cultural construct.

Additional Neurological Disorders

In this guide, we’ve discussed neurology in the context of stimulation of the sympathetic nervous system in PTSD or in elevated serotonin levels in individuals with bipolar disorder. The MCAT may test you on additional disorders with a strong neurological etiology.

(a) Aphasia

• Aphasia refers to an inability to produce or understand speech. There are two types of aphasia to be aware of: Broca’s aphasia and Wernicke’s aphasia. 
• Broca’s aphasia results from damage to Broca’s area, an area in the frontal lobe responsible for speech and language production. Individuals experiencing Broca’s aphasia are unable to produce complete and comprehensible sentences but are able to understand language well. 
• Wernicke’s aphasia results from damage to Wernicke’s area, an area in the temporal lobe responsible for language comprehension. Individuals experiencing Wernicke’s aphasia may be able to correctly pronounce words, but their sentences may lack correct meaning or sentiment.

(b) Parkinson’s disease

• Parkinson’s disease primarily affects elderly populations and manifests as a movement disorder. Individuals may experience tremors, or poor control of fine motor movements. They may also exhibit bradykinesia (slowed movements) and demonstrate a “shuffling” gait when moving or walking. 
• Parkinson’s disease seems to be caused by a downregulation of dopamine production in the substantia nigra. The substantia nigra is a region of the brain that helps promote the proper functioning of the basal ganglia through the use of dopamine. The basal ganglia are used to control smooth motor movements. L-DOPA is a dopamine precursor that is converted to dopamine in the brain, which can help therapeutically replace the dopamine that is lost due to Parkinson’s.
• Stem cell therapy has also been proposed as a treatment for Parkinson’s disease and other neurodegenerative diseases. Under this treatment method, stem cells would be used to regenerate and develop certain types of cells, including cells that develop dopamine, in the case of dopamine-deficient patients. When successful, stem cell therapy can become a long-term treatment solution.

(c) Alzheimer’s disease

• Alzheimer’s disease is a form of dementia (severe loss of cognitive ability beyond what would be expected from normal aging). It is most common in the elderly. Women are more likely to be diagnosed, and it is certainly genetically based.
• Alzheimer’s disease manifests in several hallmark neurological signs and must be diagnosed with additional brain scans and imaging. These include beta-amyloid plaques and neurofibrillary tangles of tau protein, abnormally large amounts of aggregated protein that are present in the brain. 
• Additional signs include reduced acetylcholine transmission and widespread atrophy of the brain. While there are several used therapies for Alzheimer’s disease, there is currently no known cause or cure. 

High-Yield Terms

• Psychological disorder: a characteristic set of feelings, thoughts, or behaviors that differ from the cultural norm and can cause distress to the individual suffering from them
• Biomedical approach: views the root of psychological disorders as a biomedical imbalance or disturbance
• Biopsychosocial approach: a broader view of psychological disorders that considers biomedical, psychological, and social factors when defining the origin of a disorder
• Direct therapy: helping the individual resolve their psychological disorder with medication or periodic meetings
• Indirect therapy: increasing support for the individual with help from family, friends, or other components of the individual’s social network
• Diagnostic and Statistical Manual of Mental Disorders (DSM): a standardized resource to assist clinicians to classify these disorders
• Psychotic disorders: a group of disorders that result in at least one of the following: delusions, hallucinations, disorganized thought or behavior, catatonia, or negative symptoms
• Schizophrenia: prototypical psychotic disorder; involves a period of prodrome before the onset of psychotic symptoms, which may include both negative and positive symptoms
• Prodromal phase/prodrome: a phase that occurs before the diagnosis of schizophrenia; often involves social withdrawal, deterioration, peculiar behavior, and other similar symptoms
• Positive symptoms: behaviors or thoughts that are added on to normal behavior, such as a nervous tick or hallucinations
• Negative symptoms: symptoms that represent the absence of normal behavior, like the inability to eat or lack of emotion
• Delusions: false beliefs not observed in reality and not shared by others in the individual’s culture; can include delusions of reference, persecution, or grandeur
• Hallucinations:  false observations that are not based in reality but are perceived as such; auditory hallucinations are more common than visual
• Disorganized thought: a positive symptom that refers to expressed words and thoughts strung together in a way that makes them very difficult to follow. 
• Catatonia: abnormal movements as a result of a disturbed mental state; can include spontaneous movements or the inability to move
• Flat affect: when there is virtually no evidence of emotion
• Inappropriate affect: when presented affect is discordant with the individual’s speech or behavior
• Avolition: lack of engagement or participation in goal-driven activities. 
• Downward drift hypothesis: postulates that schizophrenia leads to a decline in socioeconomic status, which in turn can lead to worsening symptoms; causes a vicious cycle of worsening schizophrenia and socioeconomic status
• Major depressive disorder: a mood disorder characterized by at least one major depressive episode that must last a period of at least 2 weeks
• Anhedonia: loss of interest in activities that used to be interesting
• Dysthymia: a depressed mood that isn’t severe enough to be classified as major depressive disorder
• Seasonal affective disorder (SAD): a major depressive disorder with a seasonal onset, typically the winter months
• Manic episodes: episodes of extremely elevated mood lasting at least one week
• Hypomania: an increased level of energy or optimism; distinguished from mania as it does not impair functioning and does not involve psychotic features
• Bipolar I disorder: alternating manic episodes that may or may not include depressive episodes
• Bipolar II disorder: hypomania with at least one major depressive episode
• Cyclothymic disorder: a combination of hypomanic episodes and periods of dysthymia
• Monoamine/catecholamine theory of depression: states that too much of the neurotransmitters norepinephrine and serotonin lead to mania, while too little leads to depression
• Generalized anxiety disorder: refers to a persistent worry about many different factors in the environment
• Specific phobias: irrational fears that are associated with specific objects or situations, such as spiders (arachnophobia) or the fear of enclosed spaces with no escape (agoraphobia)
• Social anxiety disorder: anxiety in social situations that could lead to embarrassment. 
• Panic disorder: consists of repeated panic attacks, characterized by fear, sweating, and hyperventilation
• Obsessive-compulsive disorder: characterized by obsessions (thoughts that repeatedly return to the individual and are repetitive to the point of detriment) and compulsions (behaviors that relieve the tension caused by the obsession)
• Body dysmorphic disorder: disorder in which the individual has an unrealistically negative perception of their personal appearance
• Anorexia nervosa: body-weight disorder in which individuals are overly concerned with being thin; often appear very thin and have a dangerously low body mass index
• Binging and purging: cycle of eating large quantities of food (binging) and subsequently self-inducing vomiting to expel the food that was eaten (purging)
• Bulimia: similar body-weight disorder to anorexia; individuals engage in the same patterns of binging and purging and typically appear to be of healthy body weight
• Post-traumatic stress disorder (PTSD): is onset after experiencing a traumatic event such as war, death, or other tragedies; individuals who suffer from this disorder experience intrusive symptoms, avoidance symptoms, negative cognitive symptoms, and arousal symptoms
• Dissociative disorders: marked by an apparent “escape from reality” to avoid stressors in the environment
• Dissociative amnesia: inability to recall past events; patients will dissociate themselves from reality by presenting with amnesia that is not due to any underlying neurological conditions
• Dissociative fugue: a sudden departure from normal daily activities; individuals in dissociative fugue may even forget who they are or assume a new identity
• Dissociative identity disorder (DID): formerly known as “multiple personality disorder”; an individual appears to have two or more personalities that share control of the individual
• Depersonalization: when an individual feels separated from their own mind and body
• Derealization: when an individual feels separated from their surroundings, and the world appears with a dreamlike quality
• Somatic symptom disorder: typically diagnosed when an individual has a somatic symptom that is not necessarily linked to an underlying medical condition
• Conversion disorder: similar to somatic symptom disorder in that individuals present with an unexplained somatic symptom; these symptoms typically follow traumatic events
• Illness anxiety disorder: a person is consumed with the thought of having an illness or disease
• Cluster A disorders: include paranoid, schizotypal, and schizoid personality disorders; may be well-remembered as the “weird” disorders
• Cluster B disorders: include antisocial, borderline, histrionic, and narcissistic personality disorders; may be well-remembered as the “wild” disorders
• Cluster C disorders: include avoidant, dependent, and obsessive-compulsive personality disorders; may be well-remembered as the “worried” disorders
• Stress-diathesis theory: postulates that genetics provide a biological predisposition for schizophrenia, but environmental stressors elicit the onset of the disease
• Neuroleptics: dopamine receptor antagonists used to treat schizophrenia
• Dementia: severe loss of cognitive ability beyond what would be expected from normal aging
• Beta-amyloid plaques: abnormal clusters of proteins found in the brain; a hallmark of Alzheimer’s disease
• Neurofibrillary tangles of hyperphosphorylated tau protein: abnormal clusters of proteins found in the brain; a hallmark of Alzheimer’s disease
• Parkinson’s disease: characterized by poor control of fine motor movements; seems to be caused by decreased dopamine production in the substantia nigra
• Cognitive-behavioral therapy (CBT): commonly used treatment for behavioral psychological disorder; a therapist or trained medical professional works with the patient to investigate the patterns of negative thinking or reevaluate trigger events that may have led to the psychological disorder
• Selective serotonin reuptake inhibitors (SSRIs): common therapy for depressive disorders; slows down the process of reabsorbing serotonin from synaptic clefts in the brain