"Turn illness into a weapon,” proclaimed the SPK. “The kidney stone that makes you suffer,” it declared, was the same as “the stone thrown into the control room of capitalism.” Published in 1972 by a group of students at Heidelberg University – with a foreword by Jean-Paul Sartre, who said he was “extremely impressed” by its ideas – the SPK’s manifesto stated that mental illnesses were the result of wider ills in capitalist societies. To heal the patient, the patient had to heal the system first – by violent means, if necessary.

Armed with such rhetoric, the SPK aimed to break up the encrusted structures of Heidelberg’s academic system and introduce ideas that form the foundation of modern psychoanalysis. But, as a new documentary, SPK Complex, screening this week at the Berlin film festival shows, kidney stones eventually became hand grenades: some of the collective’s members ended up joining the violent group Red Army Faction (also known as the Baader-Meinhof Group) and took part in bombings that did not cure but kill.

The story of the SPK starts in the early 1960s, at a time when the failure to address the country’s recent Nazi history was not only apparent in German politics and the arts, but also in the medical profession. Several doctors at Heidelberg University who had taken part in Hitler’s T4 euthanasia programme were still employed at the institution. Electroshock therapy was routinely practised.

Against this backdrop, Wolfgang Huber, a wild-haired assistant doctor at the university’s polyclinic, began to experiment with “anti-therapy” group treatments. “There should be no therapeutic act that has not been previously established as a revolutionary act,” he declared in 1970. “For the patient there is only one pragmatic way to combat their illness – namely the dissolution of our pathogenic, corporate-based, patriarchal society.”

Ewald Goerlich, a shy student who had struggled with depression and loneliness, was one day approached by Huber, who asked him if he, as a patient, could teach other patients. Goerlich, who was studying maths and physics in the picture-postcard town, felt out of his depth. “Listen,” he said. “I don’t really know how this works. Where did you get all your knowledge from?” “From Hegel,” his therapist replied, referring to the 18^th-century philosopher whose notion of dialectical materialism underpins Marxist thinking.

In short, says Gerd Kroske, director of SPK Complex, Huber believed capitalism made people ill. “Of course,” he says, “that was a flawed equation, because it implies that under a different system, such as socialism, illness would not exist. Which is nonsense.”

Initially, the SPK comprised 50 people, with problems ranging from childhood traumas to LSD hangovers, but numbers swelled to around 500 as the political climate in the town heated up. When former US defence secretary Robert McNamara visited Heidelberg in 1970, scuffles broke out between student protesters and police. The university reacted by banning the Socialist Student Union, whose ranks flooded the SPK, and then by firing Huber. Further protests against the expulsion followed, and eventually the university decided to continue paying Huber’s salary and gave him a couple of rooms where he could continue his work. Conveniently, they were located opposite the police station.

“At the beginning,” says SPK patient-therapist Goerlich, “we were something like a grassroots democracy, but we gradually slipped into something a lot more dogmatic.” A judge interviewed in the documentary film describes the logic that had taken root in the group as that of “a little jihad”.

One former member recalls a meeting in which a shady figure handed over a machine-gun and told the patients to rise up in armed struggle. While others question this account, in 1975, two SPK members played a part in a Red Army Faction hostage-taking at the West German embassy in Stockholm, during which two employees and two terrorists were killed.

By then, the SPK had been declared a criminal group and Huber was in prison, where he bit and spat at the doctors who tried to examine him and eventually embarked on a hunger strike. Ironically, Huber got to experience at first hand his ideas about psychiatry as a political instrument. Digging through the archives, Kroske discovered that the state prosecutor began to inquire about Huber’s mental health a year before he was due to be released, pushing the idea that he should perhaps go straight into a psychiatric unit.

In January 1976, Huber was released from prison and vanished. Although he was rumoured to be living in a commune in Spain until two years ago, Kroske was unable to track him down. Huber remains a ghostly non-presence in the film. However, the SPK still exists and even has a website, but has barricaded itself thoroughly behind incomprehensible jargon about “cosmic-social revolutionary reality-effectiveness”, “iatro-capitalism” and “thermomimetics”. It has, however, changed its name to the Patients’ Front – and its members have picketed screenings of Kroske’s documentary. There was a call threatening an attack on last Sunday’s premiere, leading to police with night-vision goggles patrolling the aisles during the screening.

All this is surprising, given that SPK Complex goes some way to assessing the group’s legacy without being blinded by its rapid descent into militancy. “From the perspective of the history of medicine,” says Kroske, “the SPK is actually a success story, because much of what was initiated at that time period is common practice today.” He points to the concept of patient care by laypersons, group living arrangements for the mentally ill, and the confrontation of Nazi legacies in German psychiatry.

“If you talk to psychiatrists today,” he adds, “many of them have a degree of sympathy for the SPK experiment, because they realise that they risked something in order to change the system.”

Philip Oltermann