RSPK Syndrome

Recurrent Spontaneous PsychoKinesis Syndrome (RSPK Syndrome) (反復性偶発性念力症候群(RSPK症候群))), commonly referred to as Poltergeist (乱雑解放(ポルターガイスト)), describes the condition of an esper where emotional stress causes them to express their power unconsciously. This expression is often destructive to their surroundings and will vary among espers and their levels.

Causes
Poltergeist (from German poltern, meaning "to rumble", "to make a noise" and Geist, meaning "ghost" or "spirit") is an alternative term for RSPK Syndrome. It is used because the phenomenon is similar to what people believe to be typical of a poltergeist. Examples include the unintentional movement of objects and an abnormal occurrence. In the Power Curriculum Program, various methods, such as medicine and suggestion, are used to separate one from reality; according to Tsukuyomi Komoe, RSPK Syndrome occurs when espers are unable to perceive reality properly due to emotional stress or trauma.

Interference on the AIM diffusion fields of espers can also cause simultaneous outbreaks of RSPK Syndrome to occur. Also when multiple overloaded espers (as with the case with Kiyama Harumi's students) with the same AIM diffusion fields are gathered together, their powers resonate and causes an occurrence of RSPK Syndrome.

Effects
Apart from the abnormal occurence of moving objects (like teacups and dolls) and other similar unnatural events, a poltergeist can also cause earthquakes. Poltergeist earthquakes occurs when the abilities of multiple out of control espers converge on a large scale, from a human sensory perspective they are perceived as earthquakes. A large enough occurence of poltergeist earthquakes can cause significant damage, and can seriously injure bystanders. In the worst case scenario, a city like Academy City could have 78% of its population be affected by a large enough occurence of RSPK Syndrome.

Sisters Arc
Terms "RSPK Syndrome" and "Poltergeist" were briefly mentioned during Tsukuyomi Komoe's talk about espers with Index and Himegami Aisa in the bathhouse.

Poltergeist Arc
Due to Kiyama Harumi's attempts at reviving her comatose students and Haruue Erii constant attempts to telepatheically contact one of them, Edasaki Banri, sporadic occurences of RSPK Syndrome occurred across Academy City, causing various amounts of damage. Because of these events, Judgment, Anti-Skill and Multi Active Rescue held a meeting on information about the recent earthquakes. With the help of Misaka Mikoto, Therestina Kihara Lifeline, the head of Multi Active Rescue was able to find Harumi and obtain custody of the children.

It was eventually revealed that Therestina is also the granddaughter of Kihara Gensei, the researcher who performed an experiment on analysing the overloading of esper abilities on Harumi's students, and planned to continue his experiment on achieving SYSTEM or level 6, by using Harumi's students as well as Erii. This would cause an overload of their abilities, theoretically achieving SYSTEM, however it would cause the destruction of Academy City.

With the efforts of Mikoto, Shirai Kuroko, Saten Ruiko, Uiharu Kazari and Harumi, they were able to stop Therestina and cure the students, thus ending the Poltergeist Incidents.