Autism spectrum disorder (ASD) is a developmental disorder characterized by [1]:
- Persistent difficulties with social communication/interactions
- Restricted/repetitive behaviors and interests
- Sensory sensitivities
Symptoms present in early childhood and impair everyday functioning.
There are various theories that ASD involves imbalances in neural excitation and inhibition pathways, particularly with the neurotransmitter glutamate [2].
As an NMDA receptor antagonist, ketamine may help improve ASD symptoms by normalizing excess glutamate activity. Small studies have shown ketamine can transiently reduce repetitive behaviors, irritability, social withdrawal, and hypersensitivity to stimuli in children and adults with ASD [3].
However, ketamine is not a standalone treatment. Its temporary effects could allow utilization of behavioral therapies during a potential “optimal learning period” after dosing [4]. But more research is still needed.
In the long term, studies indicate combining ketamine with other medications like memantine may extend behavioral improvements in ASD [5]. More extensive controlled trials are required to confirm if ketamine has lasting benefits.
References:
[1] American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596
[2] Lee EJ, Choi SY, Kim E. NMDA receptor dysfunction in autism spectrum disorders. Curr Opin Pharmacol. 2015;20:8-13. doi:10.1016/j.coph.2014.10.007
[3] Zhong W, Parrish RT, Marotta N, et al. Intranasal ketamine for adults with autism spectrum disorder and persistent self-injurious and aggressive behavior. Ann Clin Psychiatry. 2020;32(2):92-99.
[4] Singh JB, Fedgchin M, Daly EJ, et al. A Double-Blind, Randomized, Placebo-Controlled, Dose-Frequency Study of Intravenous Ketamine in Patients With Treatment-Resistant Depression. Am J Psychiatry. 2016;173(8):816-826. doi:10.1176/appi.ajp.2016.16010037
[5] Ghaleiha A, Mohammadi MR, Mohammadinejad P, et al. Minocycline add-on to risperidone for treatment of negative symptoms in patients with stable schizophrenia: Randomized double-blind placebo-controlled study. Psychiatry Res. 2018;267:540-546. doi:10.1016/j.psychres.2018.06.022