Ecstatic seizures, also known as ecstatic epilepsy or as Dostoevsky's epilepsy, are a rare type of epilepsy that involve seizures with an intensely blissful, euphoric, or ecstatic aura. They are a form of focal epilepsy. Symptoms include intense positive affect, physical well-being, and heightened awareness, as well as time dilation and other symptoms. They are often described as mystical, spiritual, and/or religious, and have sometimes been said to be "life-changing".

Ecstatic seizures are thought to be caused by epileptic activation of an area of the brain known as the dorsal anterior insula. Electrical stimulation of this part of the brain can induce ecstatic seizures. It has been theorized that ecstatic seizures caused by activation of the insula may be due to a temporary block of prediction errors associated with uncertainty and negative affect. Conceptual and neurological parallels have been drawn between ecstatic seizures and other intensely positive or mystical experiences, for instance with drugs like MDMA ("ecstasy") and psychedelics, as well as with moving musical enjoyment and deep states of meditation.

The Russian novelist Fyodor Dostoevsky, who himself had epilepsy and ecstatic seizures, first described these seizures in his writings in the mid-to-late 1800s. The first cases of ecstatic seizures reported in the medical literature were published in the late 1800s and early 1900s. As of 2023, around 50 cases of ecstatic seizures have been reported. The involvement of the anterior insula in ecstatic seizures was first elucidated in 2009, and ecstatic experiences were first artificially induced by stimulation of this brain area in 2013. Some leading historical religious figures, such as Saint Paul the Apostle and Joan of Arc, have been suspected as having ecstatic seizures.

The symptoms variably include feelings of increased self-awareness, mental clarity, certainty, feelings of "unity with everything that exists" (including the external environment), intense positive affect, a sense of intense serenity or bliss, mystical, spiritual, or religious experiences, physical well-being, a sense of "hyper-reality", and time dilation, among others. The term "oceanic" has also been invoked in describing the experiences. The physical well-being includes a feeling of warmth ascending from the feet to the head or a feeling of the body being covered in velvet.

The key and essential definitional criteria of ecstatic seizures include:

The state seems to primarily involve an absence of doubts or uncertainty rather than a primary intense positive emotion. Ecstatic seizures have been compared to the bliss of enjoying music or orgasm and have been described as much better than sex. They have also been described as life-changing, for instance resulting in people no longer fearing death or converting from atheism to religion. Alternating ecstatic and unpleasant emotions, such as anxiety, have also been reported however.

A description of Russian novelist Fyodor Dostoevsky's ecstatic auras by his close friend Nikolay Strakhov was published as follows:

For several brief moments, I feel a contentedness which is unthinkable under normal conditions and unimaginable for those who have not experienced it. At such times, I am in perfect harmony with myself and with the entire universe. Perception is so clear and so agreeable that one would give 10 years of his life, and perhaps all of it, for a few seconds of such bliss.