Antidepressants and Psychiatric Medication

The main classes of psychiatric medication — antidepressants, antipsychotics, mood stabilisers, anxiolytics and stimulants — how they work, how well they work, side effects, and practical facts patients should know.

This article summarises general knowledge, not medical advice — decisions about medication should always be made with a qualified clinician.

Antidepressants

SSRIs (such as fluoxetine, sertraline, escitalopram) block serotonin reuptake and are usually first-line for depression and anxiety disorders. SNRIs (venlafaxine, duloxetine) also block noradrenaline reuptake. Others include bupropion (dopamine and noradrenaline), mirtazapine, older tricyclics and MAO inhibitors. Benefits usually emerge over 2–6 weeks. Large analyses show antidepressants outperform placebo on average — more clearly in moderate to severe depression — but responses vary and many people need to try more than one. Common side effects include nausea, sleep changes and sexual side effects. Young people may experience increased suicidal thinking early in treatment, so monitoring is important. Stopping suddenly can cause discontinuation symptoms; tapering with medical guidance is recommended.

Antipsychotics

Used for schizophrenia, bipolar mania and other conditions. First-generation drugs (chlorpromazine, haloperidol) strongly block D2 receptors and can cause movement side effects, including the potentially lasting tardive dyskinesia. Second-generation drugs (risperidone, olanzapine, aripiprazole and others) also act on serotonin receptors and tend to cause fewer movement effects but more metabolic effects such as weight gain. Clozapine is uniquely effective for treatment-resistant schizophrenia but needs blood monitoring. In 2024 a muscarinic-based drug (xanomeline-trospium) added a new mechanism.

Mood stabilisers

Lithium remains a gold standard for bipolar disorder and reduces suicide risk; it requires blood-level monitoring. Valproate, lamotrigine and carbamazepine (originally anti-seizure drugs) are alternatives; valproate carries serious risks in pregnancy.

Anti-anxiety and sleep medications

Benzodiazepines (diazepam, lorazepam) enhance GABA and act quickly, but tolerance and dependence limit long-term use; they are dangerous combined with alcohol or opioids. SSRIs, SNRIs, buspirone and therapy are preferred for long-term anxiety.

Stimulants

Methylphenidate and amphetamines for ADHD increase dopamine and noradrenaline signalling and are effective for many, with side effects such as reduced appetite and sleep problems.

The bigger picture

Medications are usually most effective as part of a wider plan including psychotherapy, lifestyle and social support. Researchers are working on faster-acting treatments (such as ketamine-related drugs) and ways to predict who will respond to which treatment.