Methylene blue is attracting growing interest in psychiatry for the treatment of complex disorders such as severe depression, schizophrenia and Alzheimer’s disease. Thanks to its antioxidant and neuroprotective properties and its action on neuroplasticity via BDNF, it represents a potential therapeutic option for patients resistant to conventional treatments. This article examines its mechanisms of action and its role in modulating brain function.
What mental disorders can be treated with methylene blue?
Several recent studies have highlighted the effectiveness of methylene blue in doses ranging from 15 mg to 300 mg per day in treating conditions such as :
Severe depression
Severe depression, characterised by intense feelings of sadness and despair, can be difficult to treat with conventional methods. Methylene blue (2) could offer a new option for patients who do not respond to conventional antidepressants.
Schizophrenia
This complex mental disorder, which affects the perception of reality and can lead to hallucinations and delusions, also shows signs of improvement with the use of methylene blue. Scientific studies (3) suggest that it could be used as an adjuvant treatment, boosting the effectiveness of antipsychotics.
Alzheimer’s disease
Alzheimer’s disease, a form of progressive dementia, is characterised by cognitive impairment. The antioxidant and neuroprotective properties of methylene blue (4) could help slow the progression of the disease and improve certain cognitive functions.
Manic-depressive psychosis
Also known as bipolar disorder, this condition involves extreme fluctuations in mood. Methylene blue has been studied (5) for its potential to stabilise mood and reduce manic episodes.
Bipolar disorder
Bipolar disorder involves alternating periods of depression and mania. Research (6) suggests that methylene blue may help reduce residual symptoms in bipolar patients, particularly during depressive phases.
These pathologies, which are often complex and difficult to treat, seem to respond positively to this innovative therapeutic approach. By incorporating methylene blue into treatment protocols, healthcare professionals could offer more effective, personalised solutions to patients suffering from mental disorders.
How does Methylene Blue work?
Methylene blue, a member of the thiazine class of compounds, is distinguished by its neuropsychiatric applications thanks to its unique mechanisms of action. Although its chemical structure shares similarities with certain tricyclic antidepressants and carbamazepine, its effects are based on specific biological interactions that promote neuronal health.
Methylene blue acts as an alternative electron transporter in mitochondria, supporting mitochondrial function by reducing the production of free radicals (ROS) and decreasing oxidative stress (1). This mechanism, essential in the action of methylene blue to protect neurons from oxidative damage, plays a key role in the prevention of neurodegenerative diseases such as Alzheimer’s and Parkinson’s. In addition, methylene blue increases the expression and activity of mitochondrial complex IV, which contributes to more stable energy production and minimises ROS.
By inhibiting GABA-A receptors and the enzyme monoamine oxidase A (MAO-A), methylene blue modifies the levels of neurotransmitters such as serotonin, noradrenaline and dopamine. This modulation supports neuropsychiatric functions, explaining its antidepressant and anxiolytic effects.
This property is particularly beneficial for patients suffering from mood disorders, notably bipolar disorder, as it prevents the manic swings associated with other treatments.
Methylene blue prevents the aggregation of tau proteins, a process associated with neurodegenerative diseases. By limiting the formation of neurotoxic deposits, it potentially slows the progression of neuronal degeneration, thereby protecting long-term cognitive function.
What is BDNF?
BDNF (Brain-Derived Neurotrophic Factor) is an essential protein for the proper functioning of the brain. This molecule plays a key role in the growth, survival and maintenance of neurons – the brain cells responsible for transmitting information. BDNF promotes neuroplasticity, i.e. the brain’s ability to restructure itself and form new neuronal connections in response to learning and experience.
BDNF is also involved in regulating mood and memory. High levels of BDNF are associated with better mental and cognitive health, while low levels are often observed in people suffering from mood disorders, such as depression, or neurodegenerative diseases, such as Alzheimer’s. By stimulating the production of BDNF, certain treatments or compounds, such as methylene blue or psychoplastogens, could therefore help to improve neuronal resilience and the response to treatments in these conditions.
Inhibition of NMDA receptors and increase in BDNF
By acting on glutamate NMDA receptors, it indirectly stimulates brain-derived neurotrophic factor (BDNF). This increase in BDNF, combined with the effects of methylene blue, could enhance neuroplasticity, thereby promoting neuronal adaptation and improving mood. This mechanism, similar to the rapid effects of psychoplastogens such as ketamine and psilocybin, offers innovative therapeutic potential for patients suffering from depression resistant to conventional treatments. Unlike traditional psychedelics, methylene blue does not induce altered consciousness, making it more compatible with standard psychiatric treatments.
These mechanisms give MB a promising role as a complementary therapy in the treatment of complex neuropsychiatric disorders, particularly those resistant to traditional treatments.
Use of methylene blue
MB is available in various forms, including drops and capsules. When administered orally, it is vital to follow the dosage indicated by the prescribing doctor. Careful attention to the form of preparation can influence the effectiveness of the treatment and the patient’s tolerance.
Methylene blue opens up innovative therapeutic prospects in psychiatry, particularly for complex disorders such as severe depression, schizophrenia and Alzheimer’s disease. Its antioxidant and neuroprotective effects, and its action on neuroplasticity by increasing BDNF, make it a unique candidate in the neuropsychiatric field.
Although promising, its use requires rigorous medical supervision due to its complex pharmacology and dose-dependent effects. For healthcare professionals, it is crucial to keep abreast of the latest research, so as to be able to potentially incorporate this compound as an effective alternative for patients who have often failed to benefit from treatment.
Read more:
- Poteet E, Winters A, Yan L-J, Shufelt K, Green KN, et al. (2012) Neuroprotective Actions of Methylene Blue and Its Derivatives. PLoS ONE 7(10): e48279.
doi:10.1371/journal.pone.0048279 - Naylor et al (1987): A controlled trial of methylene blue in severe depressive illness, where the results showed a significant improvement in depressive symptoms.
- Deutsch et al (1997): A study of the use of methylene blue as adjuvant therapy in schizophrenia, highlighting its potential to improve clinical outcomes.
- Oz et al (2009): Exploration of the effects of methylene blue in the context of Alzheimer’s disease, highlighting its beneficial properties on cognition.
- Narsapur and Naylor (1983): Treatment proposals for manic-depressive psychosis, extending the range of possible indications for methylene blue.
- Alda et al (2011): A double-blind study examining the effects of methylene blue on residual symptoms in bipolar disorder.
