Motor Neuron Lesions

Signs of an upper motor neuron lesion include weakness, increased reflexes, increased tone (spasticity), mild atrophy, an upgoing plantar response (Babinski reflex), and clonus. On the other hand, signs of a lower motor neuron lesion include atrophy, weakness, fasciculations, decreased reflexes, and decreased tone. It is important to differentiate between the two types of lesions as they have different underlying causes and require different treatment approaches. A thorough neurological examination can help identify the location and extent of the lesion, which can guide further diagnostic testing and management.

Classical Conditioning: A Learning Theory by Ivan Pavlov

Classical conditioning is a learning theory developed by Ivan Pavlov. It suggests that events that occur together are associated and acquire a similar meaning. Unlike operant conditioning, which focuses on responses to behavior, classical conditioning looks at responses to stimuli. In classical conditioning, animals behave as if they have learned to associate a stimulus with a significant event. Pavlov demonstrated that innate responses, such as a dog salivating when it sees food, can be associated with a neutral stimulus, such as ringing a bell, so that ringing the bell can cause salivation even in the absence of food.

Important terms used in classical conditioning include stimulus generalization and discrimination, higher order conditioning, spontaneous recovery, and aversive conditioning. Extinction is the laboratory analogue of exposure therapy for anxiety disorders, while Counterconditioning involves pairing a feared conditioned stimulus with a positive outcome. Incubation occurs in fear responses, and reciprocal inhibition is a technique that aims to replace an undesired response with a desired one by counterconditioning. Some stimuli are more prone to conditioning than others, which is referred to as stimulus/biological preparedness.

The septum pellucidum is a thin layer that divides the front sections of the left and right lateral ventricles in the brain. It extends as a flat structure from the corpus callosum to the fornix.

Dementia Pugilistica: A Neurodegenerative Condition Resulting from Neurotrauma

Dementia pugilistica, also known as chronic traumatic encephalopathy (CTE), is a neurodegenerative condition that results from neurotrauma. It is commonly seen in boxers and NFL players, but can also occur in anyone with neurotrauma. The condition is characterized by symptoms such as gait ataxia, slurred speech, impaired hearing, tremors, disequilibrium, neurobehavioral disturbances, and progressive cognitive decline.

Most cases of dementia pugilistica present with early onset cognitive deficits, and behavioral signs exhibited by patients include aggression, suspiciousness, paranoia, childishness, hypersexuality, depression, and restlessness. The progression of the condition leads to more prominent behavioral symptoms such as difficulty with impulse control, irritability, inappropriateness, and explosive outbursts of aggression.

Neuropathological abnormalities have been identified in CTE, with the most unique feature being the abnormal accumulation of tau in neurons and glia in an irregular, focal, perivascular distribution and at the depths of cortical sulci. Abnormalities of the septum pellucidum, such as cavum and fenestration, are also a common feature.

While the condition has become increasingly rare due to the progressive improvement in sports safety, it is important to recognize the potential long-term consequences of repeated head injuries and take steps to prevent them.

Antipsychotics and Sexual Dysfunction: Causes, Risks, and Management

Sexual dysfunction is a common side effect of antipsychotic medication, with the highest risk associated with risperidone and haloperidol due to their effect on prolactin levels. Clozapine, olanzapine, quetiapine, aripiprazole, asenapine, and lurasidone are associated with lower rates of sexual dysfunction. The Arizona Sexual Experiences Scale (ASEX) can be used to measure sexual dysfunction before and during treatment. Management options include excluding other causes, watchful waiting, dose reduction, switching to a lower risk agent, adding aripiprazole, considering an antidote medication, of using sildenafil for erectile dysfunction. It is important to address sexual dysfunction to improve quality of life and medication adherence.

Types of Hallucinations

Reflex hallucinations occur when a stimulus in one sensory modality leads to hallucinations in another sensory modality. Autoscopy is the experience of seeing one’s own body projected into external space, typically in front of oneself. Extracampine hallucinations are those that occur outside of an individual’s sensory fields. Écho de la pensée refers to the experience of hearing voices that repeat one’s thoughts immediately after thinking them. Functional hallucinations occur when an external stimulus triggers hallucinations that are experienced simultaneously and in the same modality as the initial stimulus.

It is advisable to maintain the medication and regular monitoring as a QTC of 410 ms is within the normal range.

Amantadine and QTc Prolongation

Amantadine is a medication used to treat Parkinson’s disease and influenza. It has been associated with QTc prolongation, which can increase the risk of Torsades de points. Therefore, caution should be exercised when prescribing amantadine to patients with risk factors for QT prolongation. If a patient is already taking amantadine and develops a prolonged QTc interval, the medication should be discontinued and an alternative treatment considered. It is important to monitor the QTc interval in patients taking amantadine, especially those with risk factors for QT prolongation.

Although the occurrence of the post-injection syndrome is rare, patients must still be observed for three hours after receiving the depot injection.

, coma, respiratory depression (rare)

Inheritance Patterns and Examples

Autosomal Dominant:
Neurofibromatosis type 1 and 2, tuberous sclerosis, achondroplasia, Huntington disease, and Noonan’s syndrome are all examples of conditions that follow an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene is needed to cause the condition.

Autosomal Recessive:
Phenylketonuria, homocystinuria, Hurler’s syndrome, galactosaemia, Tay-Sach’s disease, Friedreich’s ataxia, Wilson’s disease, and cystic fibrosis are all examples of conditions that follow an autosomal recessive inheritance pattern. This means that two copies of the mutated gene are needed to cause the condition.

X-Linked Dominant:
Vitamin D resistant rickets and Rett syndrome are examples of conditions that follow an X-linked dominant inheritance pattern. This means that the mutated gene is located on the X chromosome and only one copy of the gene is needed to cause the condition.

X-Linked Recessive:
Cerebellar ataxia, Hunter’s syndrome, and Lesch-Nyhan are examples of conditions that follow an X-linked recessive inheritance pattern. This means that the mutated gene is located on the X chromosome and two copies of the gene are needed to cause the condition.

Mitochondrial:
Leber’s hereditary optic neuropathy and Kearns-Sayre syndrome are examples of conditions that follow a mitochondrial inheritance pattern. This means that the mutated gene is located in the mitochondria and is passed down from the mother to her offspring.

The development of tardive dyskinesia is thought to be caused by an increased sensitivity of postsynaptic D2 receptors in the nigrostriatal pathway. Therefore, clozapine is recommended as a treatment option since it has minimal binding affinity for D2 receptors.

Tardive Dyskinesia: Symptoms, Causes, Risk Factors, and Management

Tardive dyskinesia (TD) is a condition that affects the face, limbs, and trunk of individuals who have been on neuroleptics for months to years. The movements fluctuate over time, increase with emotional arousal, decrease with relaxation, and disappear with sleep. The cause of TD remains theoretical, but the postsynaptic dopamine (D2) receptor supersensitivity hypothesis is the most persistent. Other hypotheses include the presynaptic dopaminergic/noradrenergic hyperactivity hypothesis, the cholinergic interneuron burnout hypothesis, the excitatory/oxidative stress hypothesis, and the synaptic plasticity hypothesis. Risk factors for TD include advancing age, female sex, ethnicity, longer illness duration, intellectual disability and brain damage, negative symptoms in schizophrenia, mood disorders, diabetes, smoking, alcohol and substance misuse, FGA vs SGA treatment, higher antipsychotic dose, anticholinergic co-treatment, and akathisia.

Management options for TD include stopping any anticholinergic, reducing antipsychotic dose, changing to an antipsychotic with lower propensity for TD, and using tetrabenazine, vitamin E, of amantadine as add-on options. Clozapine is the antipsychotic most likely to be associated with resolution of symptoms. Vesicular monoamine transporter type 2 (VMAT2) inhibitors are agents that cause a depletion of neuroactive peptides such as dopamine in nerve terminals and are used to treat chorea due to neurodegenerative diseases of dyskinesias due to neuroleptic medications (tardive dyskinesia).

ADHD medications can be classified into stimulant and non-stimulant drugs. The therapeutic effects of these drugs are believed to be mediated through the action of noradrenaline in the prefrontal cortex. Common side effects of these drugs include decreased appetite, insomnia, nervousness, headache, and nausea. Stimulant drugs like dexamphetamine, methylphenidate, and lisdexamfetamine inhibit the reuptake of dopamine and noradrenaline. Non-stimulant drugs like atomoxetine, guanfacine, and clonidine work by increasing noradrenaline levels in the synaptic cleft through different mechanisms. The most common side effects of these drugs are decreased appetite, somnolence, headache, and abdominal pain.

The sphenoid bone contains a saddle-shaped depression known as the sella turcica. The anterior cranial fossa is formed by the frontal, ethmoid, and a portion of the sphenoid bones. The middle cranial fossa is formed by the sphenoid and temporal bones, while the posterior cranial fossa is formed by the occipital and temporal bones.

Memory Forms

Memory is the ability to store, retain, and retrieve information. There are different forms of memory, including sensory memory, short-term/working memory, and long-term memory.

Sensory memory is the capacity for briefly retaining the large amounts of information that people encounter daily. It includes echoic memory (gathered through auditory stimuli), iconic memory (gathered through sight), and haptic memory (acquired through touch).

Short-term memory is the ability to keep a small amount of information available for a short period of time. Atkinson and Shiffrin’s multistore model (1968) suggests the existence of a short-term storehouse with limited capacity. Baddeley and Hitch (1974) further developed the concept of short-term memory, which eventually became known as Baddeley’s multi-storehouse model (2000). This model includes the central executive, visuospatial sketchpad, phonological buffer/loop, and episodic buffer.

Long-term memory includes declarative (of explicit) memories, which can be consciously retrieved, and nondeclarative (of implicit) memories, which cannot. Declarative memory includes episodic memory (stores personal experiences) and semantic memory (stores information about facts and concepts). Non-declarative memory includes procedural memory (recalls motor and executive skills), associative memory (storage and retrieval of information through association with other information), and non-associative memory (refers to newly learned behavior through repeated exposure to an isolated stimulus).

Overall, memory is a complex and essential cognitive function that plays a crucial role in learning, reasoning, and understanding.

Abnormal movements known as athetoid movements are commonly associated with issues in the basal ganglia.

Cerebellar Dysfunction: Symptoms and Signs

Cerebellar dysfunction is a condition that affects the cerebellum, a part of the brain responsible for coordinating movement and balance. The symptoms and signs of cerebellar dysfunction include ataxia, intention tremor, nystagmus, broad-based gait, slurred speech, dysdiadochokinesis, and dysmetria (lack of finger-nose coordination).

Ataxia refers to the lack of coordination of voluntary movements, resulting in unsteady gait, difficulty with balance, and clumsiness. Intention tremor is a type of tremor that occurs during voluntary movements, such as reaching for an object. Nystagmus is an involuntary movement of the eyes, characterized by rapid, jerky movements.

Broad-based gait refers to a wide stance while walking, which is often seen in individuals with cerebellar dysfunction. Slurred speech, also known as dysarthria, is a common symptom of cerebellar dysfunction, which affects the ability to articulate words clearly. Dysdiadochokinesis is the inability to perform rapid alternating movements, such as tapping the fingers on the palm of the hand.

Dysmetria refers to the inability to accurately judge the distance and direction of movements, resulting in errors in reaching for objects of touching the nose with the finger. These symptoms and signs of cerebellar dysfunction can be caused by a variety of conditions, including stroke, multiple sclerosis, and alcoholism. Treatment depends on the underlying cause and may include medications, physical therapy, and surgery.

Throughout his career, Szasz contended that mental illness is merely a metaphor for difficulties in human existence, and that mental illnesses lack the objective reality of physical ailments like cancer. He opposed many aspects of the contemporary psychiatric system in developed countries.

Antipsychiatry is a movement that emerged in the 1960s and challenges the traditional medical model of mental illness. It argues that mental illnesses are not biological of medical conditions but rather social constructs that reflect deviations from social norms. The movement has been associated with several famous figures, including Thomas Szasz, R.D. Laing, Michel Foucault, and Franco Basaglia. These individuals have criticized the psychiatric profession for its use of involuntary hospitalization, medication, and other forms of coercion in the treatment of mental illness. They have also advocated for alternative approaches to mental health care, such as community-based care and psychotherapy. Despite its controversial nature, the antipsychiatry movement has had a significant impact on the field of mental health and continues to influence the way we think about and treat mental illness today.

The serum concentration of valproic acid may be elevated by chlorpromazine, although the reason for this is not fully understood. However, this outcome is widely acknowledged.

Chlorpromazine: Photosensitivity Reactions and Patient Precautions

Chlorpromazine, the first drug used for psychosis, is a common topic in exams. However, it is important to note that photosensitivity reactions are a known side effect of its use. Patients taking chlorpromazine should be informed of this and advised to take necessary precautions. Proper education and awareness can help prevent potential harm from photosensitivity reactions.

The college is evaluating your comprehension of the term ‘caseness’ through this question. The GHQ is an established instrument used to detect individuals who meet the criteria for ‘caseness’.

Defining ‘Caseness’ in Psychological Rating Scales

When utilizing a psychological rating scale for screening purposes, it is crucial to establish a clear definition of ‘caseness.’ This refers to the threshold at which a respondent of participant is identified as a case, typically represented by a numerical cutoff value. Without a defined caseness, the results of the screening may be ambiguous of inconsistent. Therefore, it is essential to establish a clear operational definition of caseness to ensure accurate and reliable screening outcomes.

Antidepressants can cause sexual dysfunction as a side-effect, although the rates vary. The impact on sexual desire, arousal, and orgasm can differ depending on the type of antidepressant. It is important to rule out other causes and consider non-pharmacological strategies such as reducing the dosage of taking drug holidays. If necessary, switching to a lower risk antidepressant of using pharmacological options such as phosphodiesterase inhibitors of mirtazapine augmentation can be considered. The Maudsley Guidelines 14th Edition provides a helpful table outlining the risk of sexual dysfunction for different antidepressants.

Mahler’s Separation-Individuation theory of child development proposes that personality development occurs in distinct stages. The first stage, the Autistic phase, occurs during the first few weeks of life, where the child is mostly sleeping and cut off from the world. The second stage, the Symbiotic phase, lasts until around six months of age, where the child sees themselves and their mother as a single unit. The third stage, Separation-Individuation, has four subphases. The first subphase, Differentiation, occurs between six to ten months, where the child begins to see themselves as an individual and experiences separation anxiety. The second subphase, Practicing, occurs between ten to sixteen months, where the child explores connections with the external world and people other than the mother. The third subphase, Rapprochement, occurs between sixteen to twenty-four months, where the child struggles to balance their desire for independence and proximity to the mother, often resulting in tantrums and the use of transitional objects. The fourth subphase, Object constancy, occurs between twenty-four to thirty-six months, where the child accepts the idea of object constancy and is more comfortable with the mother being separate for periods of time.

Antipsychotics and Sudden Death: Thioridazine and QTc Prolongation

Antipsychotic medications are known to carry a risk of sudden death, particularly due to their effects on cardiac function. Thioridazine, in particular, has been found to have pronounced effects on potassium channels and significantly prolongs the QTc interval, which is a measure of the time it takes for the heart to repolarize after each beat. This prolongation can lead to a potentially fatal arrhythmia known as torsades de pointes. As a result, thioridazine is most strongly associated with sudden death among antipsychotics.

However, all antipsychotics carry some degree of risk for QTc prolongation and should be closely monitored for changes in this interval. This is especially important for patients with preexisting cardiac conditions of other risk factors for arrhythmias. Regular electrocardiogram (ECG) monitoring may be necessary to detect any changes in QTc interval and adjust medication accordingly. By carefully monitoring patients and taking appropriate precautions, healthcare providers can help minimize the risk of sudden death associated with antipsychotic use.

Lewy body dementia is a neurodegenerative disorder that is characterized by both macroscopic and microscopic changes in the brain. Macroscopically, there is cerebral atrophy, but it is less marked than in Alzheimer’s disease, and the brain weight is usually in the normal range. There is also pallor of the substantia nigra and the locus coeruleus, which are regions of the brain that produce dopamine and norepinephrine, respectively.

Microscopically, Lewy body dementia is characterized by the presence of intracellular protein accumulations called Lewy bodies. The major component of a Lewy body is alpha synuclein, and as they grow, they start to draw in other proteins such as ubiquitin. Lewy bodies are also found in Alzheimer’s disease, but they tend to be in the amygdala. They can also be found in healthy individuals, although it has been suggested that these may be pre-clinical cases of dementia with Lewy bodies. Lewy bodies are also found in other neurodegenerative disorders such as progressive supranuclear palsy, corticobasal degeneration, and multiple system atrophy.

In Lewy body dementia, Lewy bodies are mainly found within the brainstem, but they are also found in non-brainstem regions such as the amygdaloid nucleus, parahippocampal gyrus, cingulate cortex, and cerebral neocortex. Classic brainstem Lewy bodies are spherical intraneuronal cytoplasmic inclusions, characterized by hyaline eosinophilic cores, concentric lamellar bands, narrow pale halos, and immunoreactivity for alpha synuclein and ubiquitin. In contrast, cortical Lewy bodies typically lack a halo.

Most brains with Lewy body dementia also show some plaques and tangles, although in most instances, the lesions are not nearly as severe as in Alzheimer’s disease. Neuronal loss and gliosis are usually restricted to brainstem regions, particularly the substantia nigra and locus ceruleus.

Culture bound illnesses are psychiatric conditions that are specific to one particular culture. There are many different types of culture bound illnesses, including Amok, Shenjing shuairuo, Ataque de nervios, Bilis, colera, Bouffee delirante, Brain fag, Dhat, Falling-out, blacking out, Ghost sickness, Hwa-byung, wool-hwa-byung, Koro, Latah, Locura, Mal de ojo, Nervios, Rootwork, Pibloktoq, Qi-gong psychotic reaction, Sangue dormido, Shen-k’uei, shenkui, Shin-byung, Taijin kyofusho, Spell, Susto, Zar, and Wendigo.

Some of the most commonly discussed culture bound illnesses include Amok, which is confined to males in the Philippines and Malaysia who experience blind, murderous violence after a real of imagined insult. Ataque de nervios is a condition that occurs in those of Latino descent and is characterized by intense emotional upset, shouting uncontrollably, aggression, dissociation, seizure-like episodes, and suicidal gestures. Brain fag is a form of psychological distress first identified in Nigerian students in the 1960s but reported more generally in the African diaspora. It consists of a variety of cognitive and sensory disturbances that occur during periods of intense intellectual activity. Koro is a condition that affects Chinese patients who believe that their penis is withdrawing inside their abdomen, resulting in panic and the belief that they will die. Taijin kyofusho is a Japanese culture bound illness characterized by anxiety about and avoidance of interpersonal situations due to the thought, feeling, of conviction that one’s appearance and actions in social interactions are inadequate of offensive to others. Finally, Wendigo is a culture bound illness that occurs in Native American tribes during severe winters and scarcity of food, characterized by a distaste for food that leads to anxiety and the belief that one is turning into a cannibalistic ice spirit.

Piaget’s Stages of Development and Key Concepts

Piaget developed four stages of development that describe how children think and acquire knowledge. The first stage is the Sensorimotor stage, which occurs from birth to 18-24 months. In this stage, infants learn through sensory observation and gain control of their motor functions through activity, exploration, and manipulation of the environment.

The second stage is the Preoperational stage, which occurs from 2 to 7 years. During this stage, children use symbols and language more extensively, but they are unable to think logically of deductively. They also use a type of magical thinking and animistic thinking.

The third stage is the Concrete Operational stage, which occurs from 7 to 11 years. In this stage, egocentric thought is replaced by operational thought, which involves dealing with a wide array of information outside the child. Children in this stage begin to use limited logical thought and can serialise, order, and group things into classes on the basis of common characteristics.

The fourth and final stage is the Formal Operations stage, which occurs from 11 through the end of adolescence. This stage is characterized by the ability to think abstractly, to reason deductively, to define concepts, and also by the emergence of skills for dealing with permutations and combinations.

Piaget also developed key concepts, including schema, assimilation, and accommodation. A schema is a category of knowledge and the process of obtaining that knowledge. Assimilation is the process of taking new information into an existing schema, while accommodation involves altering a schema in view of additional information.

Overall, Piaget’s stages of development and key concepts provide a framework for understanding how children learn and acquire knowledge.

Theories of aggression can be categorized into three main perspectives: psychodynamic, sociological/drive, and cognitive and learning. Psychodynamic theory, proposed by Freud, suggests that aggression arises from a primary instinct called thanatos, which aims for destruction and death. Sociobiological/drive theory, proposed by Lorenz, suggests that aggression is instinctual and necessary for survival, and that stronger genes are selected through aggression. Cognitive and learning theory, proposed by Berkowitz, Rotter, Bandura, and Anderson, suggests that aggression can be learned through observational learning and is influenced by environmental factors. Bandura’s work introduced the concept of reciprocal determinism, which suggests that behavior is influenced by both the environment and the individual’s behavior. Rotter’s social learning theory emphasizes the interaction between the individual and their environment, while Anderson and Bushman’s general aggression model considers the role of social, cognitive, developmental, and biological factors on aggression.

Kraepelin’s Mixed States: A Historical Overview

Kraepelin’s six types of mixed states were based on various combinations of mood, will, and thought processes. These mixed states are less common than pure mania of pure depression. Dysphoric mania and depressive mixed state are the two types of mixed states that have been reduced over the years. Other terms used to describe mixed states include agitated depression, anxious depression, irritable depression, and mixed hypomania. Despite the reduction in the number of mixed states, they remain a relevant psychopathological syndrome in modern times.

Broca’s and Wernicke’s are two types of expressive dysphasia, which is characterized by difficulty producing speech despite intact comprehension. Dysarthria is a type of expressive dysphasia caused by damage to the speech production apparatus, while Broca’s aphasia is caused by damage to the area of the brain responsible for speech production, specifically Broca’s area located in Brodmann areas 44 and 45. On the other hand, Wernicke’s aphasia is a type of receptive of fluent aphasia caused by damage to the comprehension of speech, while the actual production of speech remains normal. Wernicke’s area is located in the posterior part of the superior temporal gyrus in the dominant hemisphere, within Brodmann area 22.

When monoamine oxidase inhibitors (MAOIs) are present, the enzyme that breaks down norepinephrine is inhibited. This can lead to a hypertensive crisis if a high tyramine meal is consumed. Broad bean pods contain tyramine, which increases the release of norepinephrine. Therefore, it is important to avoid certain foods when taking MAOIs, including dried, aged, smoked, fermented, spoiled of improperly stored meat, poultry and fish, aged cheese, tap and unpasteurized beers, Marmite, and soy products.

Graves’ disease is a specific type of hyperthyroidism that is characterized by unique signs such as lid lag and retraction, exophthalmos, and pretibial myxoedema. Other signs of hyperthyroidism include low body weight and hyperactivity. However, signs such as periorbital edema, dry skin, and hoarse voice are associated with hypothyroidism.

The tuberoinfundibular pathway links the hypothalamus with the pituitary gland, rather than the pineal gland.

Neurotransmitters are substances used by neurons to communicate with each other and with target tissues. They are synthesized and released from nerve endings into the synaptic cleft, where they bind to receptor proteins in the cellular membrane of the target tissue. Neurotransmitters can be classified into different types, including small molecules (such as acetylcholine, dopamine, norepinephrine, serotonin, and GABA) and large molecules (such as neuropeptides). They can also be classified as excitatory or inhibitory. Receptors can be ionotropic or metabotropic, and the effects of neurotransmitters can be fast of slow. Some important neurotransmitters include acetylcholine, dopamine, GABA, norepinephrine, and serotonin. Each neurotransmitter has a specific synthesis, breakdown, and receptor type. Understanding neurotransmitters is important for understanding the function of the nervous system and for developing treatments for neurological and psychiatric disorders.

Catecholamines are a group of chemical compounds that have a distinct structure consisting of a benzene ring with two hydroxyl groups, an intermediate ethyl chain, and a terminal amine group. These compounds play an important role in the body and are involved in various physiological processes. The three main catecholamines found in the body are dopamine, adrenaline, and noradrenaline. All of these compounds are derived from the amino acid tyrosine. Overall, catecholamines are essential for maintaining proper bodily functions and are involved in a wide range of physiological processes.

Chlorphenamine, also known as Piriton, is classified as a first-generation antihistamine that functions by obstructing the H1 receptor. This sedative antihistamine is utilized to treat allergic conditions like hay fever. Additionally, it is present in certain cough medicines as it reduces the production of mucus.

MAOIs: A Guide to Mechanism of Action, Adverse Effects, and Dietary Restrictions

First introduced in the 1950s, MAOIs were the first antidepressants introduced. However, they are not the first choice in treating mental health disorders due to several dietary restrictions and safety concerns. They are only a treatment option when all other medications are unsuccessful. MAOIs may be particularly useful in atypical depression (over eating / over sleeping, mood reactivity).

MAOIs block the monoamine oxidase enzyme, which breaks down different types of neurotransmitters from the brain: norepinephrine, serotonin, dopamine, as well as tyramine. There are two types of monoamine oxidase, A and B. The MOA A are mostly distributed in the placenta, gut, and liver, but MOA B is present in the brain, liver, and platelets. Selegiline and rasagiline are irreversible and selective inhibitors of MAO type B, but safinamide is a reversible and selective MAO B inhibitor.

The most common adverse effects of MAOIs occurring early in treatment are orthostatic hypotension, daytime sleepiness, insomnia, and nausea; later common effects include weight gain, muscle pain, myoclonus, paraesthesia, and sexual dysfunction.

Pharmacodynamic interactions with MAOIs can cause two types of problem: serotonin syndrome (mainly due to SSRIs) and elevated blood pressure (caused by indirectly acting sympathomimetic amines releasers, like pseudoephedrine and phenylephrine). The combination of MAOIs and some TCAs appears safe. Only those TCAs with significant serotonin reuptake inhibition (clomipramine and imipramine) are likely to increase the risk of serotonin syndrome.

Tyramine is a monoamine found in various foods, and is an indirect sympathomimetic that can cause a hypertensive reaction in patients receiving MAOI therapy. For this reason, dietary restrictions are required for patients receiving MAOIs. These restrictions include avoiding matured/aged cheese, fermented sausage, improperly stored meat, fava of broad bean pods, and certain drinks such as on-tap beer. Allowed foods include fresh cottage cheese, processed cheese slices, fresh packaged of processed meat, and other alcohol (no more than two bottled or canned beers of two standard glasses of wine, per day).