Psychopharmacology is the study of substances that influence mental states. Such agents induce changes in mood, sensation, thinking, or behavior, and may be derived from plants or other natural sources or chemically synthesized in a laboratory.
Psychopharmacology encompasses medications used in the treatment of such conditions as depression, anxiety, and psychosis. It also includes agents that relieve acute and chronic pain, and others that curb insomnia and facilitate sleep.
While some psychoactive agents play an important role in reducing the suffering of those with illness, others, such as “smart drugs,” are of increasing interest for enhancing mental capabilities in healthy people.
Drugs are typically classified by their use, such as antidepressants and antipsychotics, or by their chemical makeup. Examples of the latter include opioids, often prescribed for pain relief, and benzodiazepines, often given to relieve panic and other anxiety disorders
Anxiety is one of the most common psychiatric conditions, and drugs that relieve anxiety in its many forms, from social phobia to PTSD, are collectively called “anxiolytics.” Most drugs that relieve anxiety in one way or another exert an effect on the neurotransmitter gamma-aminobutyric acid (GABA). The drugs differ in the speed with which they act to reduce symptoms and in how long the effects last.
Stimulants, including amphetamines and cocaine, boost mental alertness and energy. They are widely prescribed to heighten attention and mental focus in people with ADHD. Caffeine is also a central nervous system stimulant and may be the most widely used psychoactive substance in the world, consumed in beverages such as coffee, tea, and cola drinks.
Depression is a complex disorder, affecting many systems of the body and brain, and there is considerable debate on whether antidepressants work and for whom. They can take at least four weeks to have an effect, restoring appetite, reigniting motivation, and otherwise re-energizing sufferers. There is evidence that effective antidepressants stimulate the growth of nerve cells in the brain, creating new pathways of cognitive and behavioral flexibility.
Smart drugs, also sometimes called study drugs, are nootropics often used by students to boost academic performance, memory enhancers are the object of much research, and drugs that foster wakefulness, used to treat such disorders of excessive daytime sleepiness as narcolepsy, are of special interest to the armed forces for maintaining combat-readiness among troops on combat missions.
Some of the most promising therapies involve existing drugs used in novel ways to treat conditions that have eluded relief, such as PTSD. Ketamine, a longstanding anesthetic currently under study in depression, strengthens nerve-cell communication and seems to pave a pathway out of the fear response traumatized patients are stuck in. It is especially effective when combined with intensive psychotherapy, as is another agent with psychedelic properties—MDMA, commonly known as Ecstasy.
From anxiety to psychosis, many mental health disturbances respond to treatment with drugs. Agents with sedating effects are widely used to combat insomnia and help people fall asleep or maintain sleep, a major contributor to overall physical and mental health.
In some conditions, such as schizophrenia and bipolar disorder, medication is the only way of controlling symptoms, and treatment must be continued indefinitely to suppress symptoms. For disorders such as anxiety and depression, medication is often given for varying durations to relieve acute symptoms. It may take several trials to find the best drug in any particular case, and dosage must usually be adjusted periodically, as so many variables internally and externally influence medication effectiveness.
Research has repeatedly established that both medication and psychotherapy are equally effective for such common conditions as anxiety and depression, and the most effective treatment is a combination of the two. Drugs relieve symptoms of disorder while psychotherapy is aimed at removing the causes, particularly the habitual behavior and thought patterns that lead to episodes of acute distress.
Although psychoactive agents are widely prescribed, their use generates considerable controversy. Many question whether it is safe to use stimulants to manage ADHD in children or whether the potential for side effects outweighs the possible benefits of antidepressant medications. The controversy may largely reflect the lingering stigma attached to mental health problems and related fears that brain-based medications will alter fundamental attributes of personality; they don’t.
Many drugs— including the SSRI antidepressants such as Prozac, and stimulant medications—work directly or indirectly by altering levels of neurotransmitters, the chemical messengers in the brain. They may activate or inhibit the release of various neurotransmitters or block their reuptake in the nervous system, which increases their availability and beefs up their signaling power.
Overactivity in brain signaling pathways regulated by the neurotransmitter dopamine is thought to be responsible for the hallucinations and delusions that are characteristic of psychosis. Antipsychotic agents generally target dopamine receptors to reduce activity of the neurotransmitter. Because dopamine levels influence multiple functions in the brain, antipsychotic drugs can have unwanted side effects, especially in slowing movement.
Although at first glance it may seem paradoxical that stimulants can dampen a disorder marked by hyperactivity, it is not contradictory at the pharmacologic level. The drugs act on the neurotransmitters dopamine and norepinephrine to make them more available. The increased neurotransmitter, in turn, bolsters communication with brain areas responsible for such executive functions as the regulation of attention.
Like all other drugs, psychoactive agents have side effects in addition to their beneficial effects. Such agents typically act on one or another neurotransmitter, but since each neurotransmitter system influences many functions, the drugs can have an array of unwanted effects, from dry mouth with antidepressants to metabolic disturbances with antipsychotics. Treatment is best overseen by physicians with expertise in balancing the risks and benefits of each medication.