Psychology › Therapy & treatment
Psychiatric medicine: drugs and brain treatments
Modern era from 1949· Therapy or method
Well replicatedStrong, repeated evidence.
Drugs and device treatments that act on the brain to relieve mental disorders, mostly developed since 1949.
See it on the Psychology map →What it says
Many early drugs were found by accident: lithium for mania (1949), chlorpromazine, the first antipsychotic (1952), the first antidepressants (1957) and Valium (1963). Prozac (US 1987) launched the SSRI era; about 13 percent of US adults took an antidepressant in a given month in 2015–18. Prescribers weigh benefits against side effects such as weight gain, sexual problems or movement disorders. Along with policy changes, drugs helped shrink US mental hospitals from about 560,000 patients in 1955.
Why it matters
Medication let many people with severe illness live outside institutions, and turned psychiatry toward biology and brain chemistry.
The evidence
Placebo-controlled trials (the FDA has required proof of effectiveness since 1962) and large meta-analyses such as Andrea Cipriani's 2018 study of 21 antidepressants in about 116,000 patients.
Open questions
Why many drugs take weeks to work, why responses vary so much between people, and why placebo responses in trials have grown are all unresolved.
Inside this (8)
Connections (6)
▸Psychiatric medicine: drugs and brain treatments treats severe forms of Mental disorders: what they are and how commonWell replicated
The connection
Medication is central for severe conditions such as schizophrenia, bipolar disorder and severe depression, and widely used for ADHD, anxiety and opioid addiction. Drugs can ease symptoms faster than therapy alone, and combining the two often works best for moderate to severe illness.
Who showed it and when
Worldwide since the 1950s; in the US most antidepressants are prescribed by primary-care doctors rather than psychiatrists.
The evidence
Placebo-controlled trials and large meta-analyses show benefits, which are largest in severe illness and smaller in mild depression.
Open questions
The size of antidepressant benefits over placebo in milder cases, and the long-term effects of many drugs, remain debated.
▸SSRI antidepressants (e.g., Prozac) are among the most prescribed drugs in Psychiatric medicine: drugs and brain treatmentsWell replicated
The connection
SSRIs were safer and simpler to prescribe than the older tricyclic antidepressants, which could be fatal in overdose. Family doctors began prescribing them widely, and they became a pillar of psychiatric medicine for depression, anxiety, OCD and PTSD.
Who showed it and when
From Prozac's 1987 US approval; US antidepressant use rose from roughly 2 to 3 percent of people in 1988–94 to about 13 percent of adults in 2015–18.
The evidence
CDC national health surveys track use, and sertraline and escitalopram rank among the most prescribed drugs in the US.
Open questions
Critics argue they are overprescribed for mild distress, where benefit over placebo is small; others note many people with depression still go untreated.
▸Lithium for bipolar disorder launched the modern era of Psychiatric medicine: drugs and brain treatmentsWell replicated
The connection
Cade's 1949 discovery was the first time a drug clearly treated a specific mental illness rather than simply sedating patients. With chlorpromazine (1952) and the first antidepressants (1957), it launched modern psychopharmacology and the idea that mental disorders have treatable biology.
Who showed it and when
Melbourne, Australia, 1949; little noticed until Mogens Schou's Danish trials in the 1950s–60s won wider acceptance.
The evidence
Cade's published report and histories of psychiatry, such as Edward Shorter's, document lithium as the first modern psychiatric drug.
Open questions
Some historians give chlorpromazine more credit, since it spread worldwide within a few years while lithium took two decades to be widely adopted.
▸Antipsychotic medications transformed Psychiatric medicine: drugs and brain treatmentsWell replicated
The connection
Chlorpromazine was the first drug that reliably reduced psychosis, launching modern psychopharmacology. Together with policy changes, it helped empty overcrowded state hospitals and moved psychiatry from custodial care and drastic procedures such as lobotomy toward medication and outpatient treatment.
Who showed it and when
Chlorpromazine reached the US as Thorazine in 1954, when state mental hospitals held over half a million patients; the numbers fell steadily afterward.
The evidence
Hospital census records trace the timing, and controlled trials in the 1950s–60s, including a large 1964 NIMH study, confirmed the drugs worked.
Open questions
Historians debate how much deinstitutionalization owed to drugs versus Medicaid funding and civil-rights reforms, and how underfunded community care fed homelessness and imprisonment.
▸Brain stimulation: ECT and TMS is the device-based branch of Psychiatric medicine: drugs and brain treatmentsWell replicated
The connection
Alongside drugs, psychiatry uses devices that act on the brain directly: ECT, which triggers a brief seizure; TMS, which uses magnetic pulses; and vagus nerve and deep brain stimulation. These are typically used when medication and therapy have not worked.
Who showed it and when
ECT in Rome, 1938; vagus nerve stimulation approved for depression in 2005; TMS cleared in 2008; deep brain stimulation for severe OCD allowed under a special exemption in 2009.
The evidence
Sham-controlled trials support ECT and TMS for depression; evidence for vagus nerve and deep brain stimulation is weaker.
Open questions
Newer approaches, such as rapid, brain-scan-guided TMS courses cleared in 2022, show promise, but long-term results and how they work are still unclear.
▸The placebo effect sets the bar for Psychiatric medicine: drugs and brain treatmentsWell replicated
The connection
Because people with depression, anxiety and pain often improve on dummy pills, a psychiatric drug must beat placebo in blinded randomized trials to prove it works. High placebo responses make that bar hard to clear, and many promising drugs have failed it.
Who showed it and when
US law since the 1962 Kefauver-Harris Amendments requires proof of effectiveness, usually from placebo-controlled trials; Henry Beecher at Harvard had championed such controls.
The evidence
Analyses of FDA trial files by Arif Khan, Irving Kirsch and others show roughly 30 to 40 percent of placebo patients in antidepressant trials count as responders.
Open questions
Why placebo responses in psychiatric trials have risen over decades; theories include higher patient expectations, more trial sites and looser enrollment.