Patricia Casey: However invisible it may be, a cult can have overwhelming power over a mind
The newspaper headlines have been suggesting that the Irishwoman found in London, having been enslaved for more than three decades, may have met her captors through a shared Maoist ideology that ultimately led to them living in a collective.
There are four women and one man, although one of the women is only 30 and it seems she has spent all of her life in captivity. If the story is correct she was a baby when this group first met.
Ultimately, we are told, the collective broke up and the two older women stayed on for reasons yet unknown. We do not know for certain if they were part of a cult or if they were there voluntarily, but if so, it suggests the power of indoctrination that is still rife in our world.
Alternatively, they may simply have been held captive against their will, just as Ariel Castro held three young women in captivity for 11 years in Cleveland until earlier this year.
Cults and sects have both been mentioned in relation to this case and they are often confused. Sects are splinter groups from mainstream religions.
The term is sometimes one of disapproval but not always. Cults on the other hand always carry a negative connotation and are not always religious. They may be secular or political.
They use a pyramidal structure of management within the organisation, which is deeply authoritarian.
Deception is used to recruit members and they are not told what the organisation does, what its goals are or what is expected of its members.
Most infamously, cults are known for the brainwashing techniques they use (also called mind control, coercive persuasion or thought reform) in which every aspect of the person's life is controlled.
It has to be pointed out that not all cult experts accept the idea of brainwashing, but most do. Isolation of members from the outside world leads to the absence of any countervailing ideas or attitudes.
This promotes intense and prolonged introspection and a distorted sense of reality.
New members may be prevented from meeting others in the organisation except those who are long-term and deeply committed members.
Contact with members may, in the initial stages, be supervised so as to prevent contamination by the opinions of others.
Any concerns that the individual may have about the organisation cannot be subject to any reality check. Indeed, the cult leaders may instil in the person the belief that outsiders are wrong, evil and even dangerous, generating a sense of "them and us". And of course separation from family is mandatory.
As well as this splitting and the belief that the world is a place of threat, every activity of the member is controlled, from the food they eat, to how they dress, to the amount of time spent alone.
Indeed there is no opportunity for self-analysis or scrutiny of what the organisation is about.
With the threat from others and the deprivation of critical thinking inculcated, increased dependency on the cult follows. Coupled with sleep deprivation, the individual is undermined so that talents they possess are scorned.
In this induced state of helplessness, the person has nowhere to turn except to the leader and other members of the organisation, and so they become enveloped.
The late 20th Century saw a number of major cult leaders. Jim Jones, a self-proclaimed atheist, preached "apostolic socialism". He was leader of the People's Temple.
In 1978, at Jonestown, Guyana, over 900 of its members, including children, died from cyanide poisoning. Jones took his own life by shooting.
David Koresh became leader of the Branch Davidians in 1988. Koresh believed that an apocalypse was imminent and began stockpiling weapons for his Army of God.
He also practised "spiritual weddings" with "God-chosen" young women of all ages.
When their compound, known as Mount Carmel, was raided in 1993, a 51-day standoff ensued. Koresh shot himself while 76 Davidians, including children, were killed in fires started in the compound.
Other cult leaders include Charles Manson and Osama bin Laden.
It is clear that cults can impact upon hundreds or just the few. But whatever the number, breaking free and returning to functional, day-to-day living poses enormous difficulties.
And one of the differences between being held captive as a result of kidnapping and having freely entered a cult, is the challenge to one's judgment and self-awareness that cult membership engenders.
On the face of it, there may be little difference between being held as a cult member and being kidnapped, since both curtail freedom. The dynamic of this, though, is much different between the two situations and it becomes immensely important in treatment and re-integration after the event.
Whatever the cause of the women's entrapment in the house in Brixton, the initial cause must be kept in mind in the months and years ahead, as they face their rehabilitation back into ordinary life.