RSPK Syndrome

Recurrent Spontaneous PsychoKinesis Syndrome (RSPK Syndrome) (反復性偶発性念力症候群 (RSPK症候群)) is a term used to refer a condition that affects the espers of Academy City, wherein an esper loses control over themselves, causing a subconscious and uncontrollable outburst of power. The manifestation of this phenomena varies by esper at an individual level.

Causes
Poltergeist (乱雑解放 (ポルターガイスト) ) (from German poltern, meaning "to rumble", "to make a noise" and Geist, meaning "ghost" or "spirit") is the common term used to refer to RSPK Syndrome, as the manifestation of the phenomena is similar to the actions of a poltergeist of lores, like moving objects or other unnatural occurrences. In the Power Curriculum Program, various methods are used to seperate one from normal reality, according Tsukuyomi Komoe, RSPK Syndrome occurs when espers cannot perceive reality properly due to mental 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 are happening all around Academy City, causing various amounts of damage. Because of these events, Judgment, Anti-Skill and Multi Active Rescue have formed a meeting on information about the recent earthquakes. With the help of Misaka Mikoto, Therestina Kihara Lifeline, the head of Multi Active Rescue were able to find Harumi and obtain custody of the children.

It is 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 plans to continue his experiment on achieving SYSTEM or level 6, by using Harumi's students as well as Erii. This wll cause an overload of their abilities, theoretically achieving SYSTEM, however it can cause the destruction of Academy City.

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