Psychopharmacology is a branch of Pharmacology and psychiatry that deals with medications used to treat mental disorders. This field has come a long way in recent years, and many effective treatments are now available for mental illnesses.

The study of medications and their effects on the human body is pharmacology, and the study of drugs only treating mental disorders is known as Psychopharmacology. 

Every day some discoveries help us understand how these drugs work, allowing medical experts to better treat mental disorders with an improved understanding of the mechanism of medicines on our brain and nerve system.

So, psychopharmacology is the scientific study of how different drugs affect mood, sensation, and thinking. Anyone who studies the effects of psychotropic drugs on the human brain is known as Psychopharmacologist. Psychopharmacologists need to understand all the clinically relevant principles of pharmacokinetics, and pharmacodynamics, such as protein binding half-life, which can vary greatly depending on everyone’s genes, mechanism of action of all psychotropic drugs, and interactions between different medications.

The use and application of psychoactive substances have been used throughout history. Still, it’s only recently that these applications have attained the same level as scrutiny given to lab-made compounds. The term “psychopharmacology” was likely coined by David Macht in the 1920s when he introduced this new field that studied how different drugs affect brain function.

Psychopharmacologists should understand basic concepts like how these psychoactive drugs work. This article will specifically discuss Neurotransmitters and Hormones because these drugs work by acting on them.

Neurotransmitter

Neurotransmitters are the messengers of our body’s systems. They are endogenous chemicals that allow signals to be passed between cells in different parts or organs while transmitting information from one cell type (such as muscle) to another through these receptor channels. Communication between two neurons happens in the synaptic cleft (the small gap between the synapses of neurons). The brain needs neurotransmitters like dopamine and serotonin because they regulate many important functions, including heart rate and many other functions.

Modern Psychopharmacology is largely due to advances in our understanding of chemical neurotransmission. Knowing about chemical neurotransmission is essential if you truly want to understand how drugs impact our brains.

Some of the most popular psychoactive drugs affect neurotransmitters and can be viewed as chemicals through which neurons primarily communicate. Following are some of the mechanisms by which psychoactive drugs affect the Neurotransmitter;

• One way they do this is by serving as a precursor for the Neurotransmitter;
• Others include the blocking of neurotransmitter production,
• Some drugs are also responsible for preventing the storage of neurotransmitters in the presynaptic vesicle.
• They can also wholly activate or inhibit the release of neurotransmitters,
• Sometimes they can restore or block the post-synaptic receptors,
• Primarily inhibit neurotransmitter reuptake by the presynaptic neuron.

Psychoactive drugs almost exert their mind-altering effects by acting on these neurotransmitters and modifying one or more aspects of synaptic transmission.

Here is a list of essential neurotransmitters affected by psychotropic drugs;

• Acetylcholine—this Neurotransmitter is involved in the body’s learning, memory, and mood. It’s a part of the autonomic nervous system that contracts smooth muscles, increases bodily secretions, dilates blood vessels, and slows the heart rate.
• Dopamine— is another neurotransmitter in motor circuits for reward and pleasure centers. This one is also involved in Parkinson’s Disease and Schizophrenia.
• GABA (Gamma Amino Butyric Acid)—This NT involves anxiety, epilepsy, fear, stress, and inhibitory neurotransmitter diseases. It blocks impulses between nerve cells in the brain; a low level of this NT can cause chronic pain, anxiety, and epilepsy. 
• Glutamate— is an amino acid and one of the brain’s most commonly found excitatory neurotransmitters. It helps in learning, memory, communication, and excitatory neurotransmitter diseases.
• Norepinephrine—(another name is Noradrenaline) is a naturally occurring chemical in the body that acts as a stress hormone and Neurotransmitter. The adrenal medulla in the human brain produces this hormone in reaction to low BP as it cause constriction of blood vessels, that’s why it causes an increase in blood pressure. Too much of this Neurotransmitter can cause anxiety, high blood pressure, increased heart rate, stress, and sleep disturbances. Norepinephrine can be crucial in your body’s “fight-or-flight” response.
• Serotonin— Also known as 5HT, is a monoamine neurotransmitter primarily found in the digestive system but involved in aggression, wound healing, bone health, depression, desire, mood, sleep, schizophrenia, and sexual desire.

Hormones

Hormones are secreted by endocrine glands into the bloodstream and convey messages within the body to act on the distant target cells. At the same time, the neurotransmitters are secreted by nerve cells in the brain and travel across the synapse to act on the nearby cells. Hormones work slowly, over time, affecting many different processes like growth, development, and metabolism, while the Neurotransmitter is fast and short-acting. 

Psychoactive drugs can also work by affecting the communication between cells through hormones. Hormones and neurotransmitters work in very different ways. Neurotransmitters can only travel a microscopic distance before reaching their target at the other side of your synaptic cleft. At the same time, hormones often have long-distance traveling abilities that allow them to reach cells anywhere throughout our bodies. Here is how the psychoactive drugs work on hormones;

• Psychotropic medications can change the secretion of many hormones;
• Hormones may also improve the behavioral responses to drugs.
• Some hormones themselves sometimes have psychoactive properties; and
• The secretion of some hormones, mainly those dependent on the pituitary gland, is controlled by neurotransmitter systems in the brain.

Psychotropic Medication/Drugs

Psychopharmacology [1] can be further classified into many different classes of psychotropic medications. In this section of the article, we will discuss them one by one;

Antidepressants

Antidepressants are a class of medications that can relieve symptoms in people who suffer from depression, social anxiety disorder, or other conditions.

Antidepressants are a medication that has been used for over 50 years. They’re increasingly popular these days, too.

These drugs can cause various side effects, including tremors, sleep disturbances, Nausea, nervousness, and sexual problems. 

The list of medications for depression is further classified into many different groups of drugs like SSRIs, SNRIs, Tricyclic antidepressants, MAO inhibitors, and Noradrenaline and specific serotoninergic antidepressants (NASSAs).

SSRIs (Selective Serotonin Reuptake Inhibitors)

SSRIs are the most commonly prescribed type of antidepressant. They work well in treating depression and have few side effects than other medications for this condition, making them popular among doctors who want something safe yet effective at relieving symptoms associated with major depressive disorder or seasonal affective disorders.

Other than treating depression, your doctor may also prescribe these drugs for obsessive-compulsive disorder (OCD), panic disorder, bulimia, bipolar disorder, generalized anxiety disorder, post-traumatic stress disorder (PTSD), premenstrual dysphoric disorder (PMDD), and anxiety. 

SSRIs increase serotonin levels in the brain as they work by inhibiting serotonin reuptake, which then stays in greater concentrations at nerve endings. This increased amount helps create an anti-depressive effect on moods and other physical symptoms such as insomnia or Nausea caused by too much 5HTP intake. This means there will be more 5HT in this area which can stimulate receptors allowing for stronger neurotransmission and better mental health overall.

The most commonly used SSRI drugs are 

• Citalopram, 
• Escitalopram, 
• Fluoxetine (Prozac, Sarafem), 
• Fluvoxamine, 
• Paroxetine, and 
• Sertraline.

Although they are still considered safe, they may cause side effects like Nausea, vomiting or diarrhea, headache, drowsiness, dry mouth, insomnia, nervousness, agitation or restlessness, dizziness, sexual problems, such as reduced sexual desire, difficulty reaching orgasm, or inability to maintain an erection (erectile dysfunction).

SNRIs (Serotonin and noradrenaline reuptake inhibitors)

SNRIs help treats major depression and mood disorders such as anxiety or obsessive-compulsive thoughts. They also may help treat ADHD if the person has failed treatment with another medication that causes side effects like irritability.

They work by increasing levels of serotonin and norepinephrine, two neurotransmitters in the brain that play a crucial role in mood stability. Typical SNRI drugs examples are 

• Venlafaxine, 
• Duloxetine, 
• Levomilnacipran and 
• Desvenlafaxine.

These drugs are thought to restore the levels of 5-HT and Noradrenaline by binding at their reuptake transporters, preventing degradation and reuptake of Noradrenaline. This leads to the accumulation of monoamines in your brain’s synapses, which returns it within normal ranges.

These drugs can cause side effects like Nausea and dry mouth (Very common). At the same time, they may also cause less frequent side effects like Tiredness, Loss of appetite, Constipation, Insomnia, Changes in sexual function, such as reduced sexual desire and erectile dysfunction, etc.

Tricyclic Anti Depressants

Tricyclic antidepressants or TCA medications have been around since the late 1950s. They work well for treating depression and are considered one of the first-line antidepressant drugs to hit markets alongside neurotransmitters like dopamine, producing feelings such as happiness or joyfulness through the brain’s reward system. Despite this treatment’s success, however, some drawbacks are still associated with its usage, including side effects that may be difficult to tolerate by specific individuals.

TCA also increases the level of Serotonin and Dopamine in the brain, but they do this with a different mechanism. Tricyclic antidepressants work in the brain to help elevate mood, and they do this by keeping more of these natural chemicals available for use so that you can be happy.

Commonly used Tricyclic antidepressant drugs are 

• Amitriptyline, 
• Amoxapine, 
• Desipramine, 
• Doxepin, 
• Imipramine, 
• Maprotiline, 
• Nortriptyline, 
• Protriptyline, and 
• Trimipramine.

These drugs can also cause side effects like drowsiness, blurred vision, constipation, dry mouth, drop in blood pressure, and urine retention. They may also cause other side effects not listed here. Please consult your doctor if you experience other side effects.

Antipsychotic Drugs

Antipsychotics are a class of medication that can manage psychosis, primarily schizophrenia and other disorders. They work best with mood stabilizers and make up the mainstay treatment for bipolar disorder.

Some of the most common antipsychotic drugs include 

• Risperidone, 
• Quetiapine, 
• Olanzapine, 
• Ziprasidone, 
• Paliperidone, 
• Aripiprazole, and 
• Clozapine.

Dopamine is one of the neurotransmitters present in our brain that carry messages from one part to another. It’s thought high levels of this Neurotransmitter may cause you to feel differently and develop symptoms like psychosis. Hence, doctors prescribe one of the above antipsychotic medications, which orally reduce or restore balance with other sources for this chemical imbalance.

Potential side effects of antipsychotic drugs include dry mouth, dizziness, blurred vision, movement effects, weight gain, sedation, loss of menstrual periods in women, dry mouth, sexual problems, fluid retention, and headaches.

Benzodiazepines

Benzodiazepines are drugs that can be prescribed to treat many conditions, including anxiety, panic attacks, seizures, and insomnia. The use in the long-term is not recommended because it may lead you towards dependence on the medication or adverse effects such as tolerance/resistance, which create problems with effectiveness over time.

Benzodiazepines work by binding to specific sites on the GABAA receptor, disinhibiting brain activity. This leads benzodiazepine users to feelings of calmness and relief from anxiety or other disorders causing problems for them in their lives.

Commonly used benzodiazepines approved by FDA include 

• Alprazolam, 
• Chlordiazepoxide, 
• Clonazepam, 
• Clorazepate, 
• Diazepam, 
• Estazolam, 
• Flurazepam, and 
• Lorazepam.

These drugs can cause drowsiness, light-headedness, confusion, unsteadiness, dizziness, slurred speech, muscle weakness, blurred vision, dry mouth, tremors, and memory problems. They may also cause other side effects. Please consult your doctor before using these drugs because they can cause tolerance and resistance to these drugs.

Stimulants

Stimulants, also known as central nervous system (CNS) stimulants, are drugs that speed up messages traveling between the brain and body. Depending on their kind, they can make you feel more awake, alert, or confident, but some common ones include caffeine, nicotine, amphetamines, and cocaine.

Cocaine is a powerful stimulant that can have many effects, including increased alertness and feelings of exhilaration. Cocaine’s interactions with neurotransmitters may also lead to decreased fatigue levels and users’ overall sense of well-being.

These are the most commonly prescribed drugs for Attention deficit hyperactivity disorder (ADHD) and Narcolepsy. They work by increasing dopamine and norepinephrine concentration in the brain. Dopamine is a neurotransmitter linked with motivation, pleasure, attention, and movement. 

Other drugs are used in Psychopharmacology, like hallucinogens, Hypnotics, Cannabis, opioids, etc. 

Commonly used Stimulants drugs are;

• Amphetamines 
• Dextroamphetamine
• Lisdexamfetamine
• Methamphetamine
• Methylphenidate

These drugs are generally safe when used as prescribed, but please note they carry a risk of misuse, abuse, and dependence, and they should only be used with doctor permission. These drugs also have a black box warning from FDA, which means that they cause addiction and abuse.

Bottom Line—Psychopharmacology

Although there is still much to learn about the workings of the human brain, we have come a long way in understanding how it affects behavior. The field of psychopharmacology has grown exponentially in recent years as researchers uncover new ways to treat mental health disorders using medication. As more and more people are diagnosed with conditions like anxiety or depression, the need for effective treatments will only continue to grow. So far, pharmacological interventions are highly successful in treating many mental health disorders. However, as with any treatment, there are risks associated with taking psychiatric medications. Before starting any medication therapy, you must discuss all potential risks and benefits with your doctor.