Ketamine’s journey began in 1962 when it was first synthesised by American chemist Calvin Stevens. Initially developed as a veterinary anesthetic, it quickly found its way into human medicine, receiving approval for human use in 1970. Its rapid onset of action and short duration made it a valuable tool during the Vietnam War, where it was extensively used as a battlefield anaesthetic.
The 1980s saw ketamine’s darker side emerge as it began to be used recreationally, raising concerns about its potential for abuse and addiction. However, the 1990s marked a turning point as researchers started to explore its potential therapeutic benefits for mental health conditions, including depression and anxiety disorders.
A significant milestone was reached in 2019 when the FDA approved esketamine, a nasal spray formulation of ketamine, for the treatment of treatment-resistant depression. Today, ketamine is being studied and used as a treatment for a range of mental health conditions, including post-traumatic stress disorder, bipolar disorder, and chronic pain, showcasing its versatility and therapeutic potential.
Ketamine’s effects vary depending on dose, route of administration, and individual response. Below are its three main effects:
1. Anaesthetic Effects
- At high doses, ketamine induces a dissociative state, meaning patients may feel detached from their body and surroundings.
- It is widely used for surgical anesthesia, especially in emergency settings, pediatrics, and low-resource areas where anesthesiologists are not always available (Sinner & Graf, 2020).
- Unlike other anesthetics, ketamine preserves airway reflexes and breathing, reducing the risk of respiratory depression (Peltoniemi et al., 2016).
It’s important to monitor patients for potential side effects during or following ketamine infusion sessions. This is why assisted therapy should only be conducted under medical supervision.
2. Psychedelic Effects
- At moderate doses, ketamine produces altered states of consciousness, which include perceptual distortions, time dilation, and mystical-type experiences (Dore et al., 2019).
- These effects have led to the use of ketamine in psychedelic-assisted therapy, where guided experiences can help process trauma, depression, and existential distress (Dakwar et al., 2022).
3. Antidepressant Effects
- At lower doses, ketamine rapidly reduces symptoms of depression, often within hours – unlike traditional antidepressants, which may take weeks to work (Wilkinson et al., 2018). Ketamine infusion therapy, which involves administering ketamine intravenously, has shown promise in rapidly reducing symptoms of depression, particularly in treatment-resistant cases.
It enhances neuroplasticity, meaning it helps the brain form new connections, which may explain its long-term benefits for mood disorders (Zanos & Gould, 2018).
Benefits of Ketamine Treatment
One of the most remarkable benefits of ketamine treatment is its rapid antidepressant effect. Unlike traditional antidepressants that may take weeks to show results, ketamine can produce improvements in depressive symptoms within hours or days of treatment. This rapid onset is particularly beneficial for individuals with treatment-resistant depression, offering hope where other treatments have failed.
Ketamine also demonstrates significant anti-anxiety effects, reducing symptoms of anxiety disorders, including social anxiety disorder and post-traumatic stress disorder. For individuals suffering from anxiety symptoms or from chronic pain, ketamine has proven effective in providing relief, especially in conditions like complex regional pain syndrome.
Moreover, ketamine has been shown to improve cognitive function in individuals with depression and anxiety disorders, enhancing overall mental health. Some studies even suggest that ketamine may offer long-term benefits, continuing to provide relief even after treatment has been discontinued.
Which Conditions Can Ketamine Treat?
Although initially an anaesthetic, ketamine is now used off-label for psychiatric and pain conditions. Some of the main conditions include:
Treatment-Resistant Depression (TRD)
- One of the most significant breakthroughs in psychiatry, ketamine has been found to rapidly relieve depressive symptoms, particularly in people who have not responded to other treatments (Berman et al., 2000). For individuals suffering from severe depression, ketamine offers a potential lifeline, providing rapid relief from debilitating symptoms.
- The FDA-approved esketamine (Spravato®), a nasal spray derived from ketamine, for treatment-resistant depression in 2019 (Daly et al., 2018).
Suicidal Ideation
- Ketamine has been shown to reduce suicidal thoughts within hours, offering a life-saving option for individuals in crisis (Grunebaum et al., 2018).
Post-Traumatic Stress Disorder (PTSD)
- Research suggests that ketamine reduces PTSD symptoms by altering memory reconsolidation, making it a potential alternative to traditional PTSD treatments (Feder et al., 2014).
Chronic Pain Disorders
- Ketamine is used for conditions like neuropathic pain, fibromyalgia, and complex regional pain syndrome (CRPS) by modulating pain pathways in the nervous system (Michelet et al., 2018).
Obsessive-Compulsive Disorder (OCD) & Anxiety Disorders
Early studies indicate ketamine can help reduce compulsive behaviours and anxiety, particularly in patients who are living with depression symptoms and have not responded to standard treatments (Rodriguez et al., 2013).
Ketamine’s therapeutic potential extends to a variety of mental health disorders, offering hope for patients with conditions that are difficult to treat with conventional therapies.
