While paranoia is not infectious in the usual sense, it is certainly contagious. It can grow in favourable circumstances and take advantage of modern technology as a persuasive evangelical tool.

Paranoia is not classified as an infectious disease. It is not caused by a virus or a bacterium. It does not spread through infectious faeces or saliva. Social distancing will not prevent it; in fact such a strategy would only aggravate it.

Paranoia has always been with us. It exists along a spectrum – such a useful term in medicine these days. I find it helpful to see paranoia as a landscape, the kind you would see somewhere near the Rockies or the Himalayas.

Imagine a valley in front of you, with some rolling hills and wide fertile plains. A few of the hills are a little higher and rougher than the surrounding countryside. Beyond that you will see the foothills of the mountains, getting higher and a little more challenging to explore. The foothills then give way progressively to higher peaks. Those below the snow line are steep and rocky, clearly a very different environment to the valley below. Looking even higher, there are the steep, sheer peaks of the alps – covered in snow, forceful and dominating, a totally foreign environment. Thunder and lightning is common at those heights and avalanches threaten the lives of anyone who attempts to climb or conquer them.

In this analogy, the fertile plains and rolling hills represent the majority of the population, living close to one another, cooperating and productive, getting on

as a community. They don’t have to agree on everything but as a group they set the limits, agree on official roles and deal with dissent and infringements through accepted processes and sanctions.

The hills in the valley that are a little higher and rougher represent people in the community that are hard to get on with, less trusting, wishing to lead their own lives and be left alone by authorities they struggle to recognise.These people have paranoid personality traits. Their neighbours see them as eccentric oddballs but keep their distance and generally tolerate them as part of a diverse society.

The foothills are a further step away from the valley community. They are people whose paranoia becomes intrusive and more troublesome for both themselves and others. They see threats where others would see coincidences. They tend to become openly hostile. Some become vexatious litigants, repeatedly suing councils or governments over their perceived persecutions. They become involved in repeated neighbourhood disputes. If they are in a relationship, the paranoia may take the form of excessive jealousy and coercive control. These people have paranoid personality disorders. If they also have narcissistic and psychopathic, unfeeling personality traits, they are more likely to become violent, especially under the influence of alcohol or drugs.

The higher peaks of the mountain range, below the snow line, represent people whose paranoia goes yet a step further, to become clinically significant paranoid reactions. Suspicion, hyper-vigilance and frankly false beliefs come to dominate their lives and behaviour. These reactions may well be temporary. They may be triggered by life events, stress, drug abuse, social difficulties or

isolation and they may settle with improved circumstances and sobriety. But they may be sustained by apparent validation from others who come to share similar beliefs.

The highest, rockiest, snow covered peaks represent the most serious paranoid psychoses. Suspicion and distrust become consolidated and organised into firm delusional beliefs that are clearly out of touch with reality, not amenable to reason and often increasingly bizarre in content. These people suffer from the devastating effects of severe disorders such as delusional psychosis and paranoid schizophrenia, with their basis in brain abnormalities, often inherited.

So that is the paranoid spectrum, ranging from eccentric, even amusing, personality traits, through more and more troublesome paranoia from multiple causes and, at the serious end of the spectrum, the paranoid psychoses.

Paranoia is at its core a sense of distrust, fear of others, suspiciousness and a tendency to interpret events in a self-referential and potentially threatening manner. Grandiose ideas or delusions are often part of the mixture. In decades past, paranoia would often lead to social isolation and withdrawal from active participation in society. Forced isolation makes paranoia worse. Deafness and partial blindness has been reported in the past to lead to a tendency in some sufferers to misinterpret the environment in a paranoid way.

The shape of a paranoid delusion will vary with the times and the cultural setting. In the 1950s a person in our culture may have developed the belief that their ideas and the voices in their head were implanted by rays from the Soviet Union’s recently launched Sputnik satellite. A decade or so later, the ideas

might have been attributed to laser beams; later still the cause may be interpreted as due to a computer chip implanted in a tooth by a dentist or by a surgeon during a brain operation. Nowadays, malign use of mobile phones or the Internet is a more popular explanation. In other cultures, the influences of tree spirits or evil medicine men may feature in the person’s explanation. The delusional flesh changes with the times and personal experiences but the underlying skeleton of brain abnormalities is the same process.

So what might lead to paranoia becoming contagious and spreading from one individual to another? Outside influences playing upon an individual’s anxieties and insecurities hold the answer.

The simplest and well-known example is that phenomenon called by its French name “Folie à Deux” – Madness of Two. This is a shared psychotic disorder. One partner in a close relationship, most often a dominant male, suffers from a severe disorder – a delusional psychosis or paranoid schizophrenia – in a situation where the couple is isolated. The more submissive, possibly dependent, partner is subject to such control and influence that they come to share the paranoid beliefs of the dominant partner. In my earlier landscape analogy, the male is the highest alpine peak; his partner is like a peak below the snow line – suffering a paranoid reaction.

If such a couple comes to psychiatric attention and treatment, the first strategy is to separate the couple, temporarily preventing them from communicating with each other, while treating the dominant male with anti-psychotic medication. At the same time, education and therapy for the other partner, will usually achieve the development of insight and the resolution of that

individual’s delusional beliefs. The paranoid reaction is temporary and reversible, but the dominant partner’s psychosis will probably persist, albeit modified and controlled with long-term medication.

More widespread contagion of paranoia can be understood by recognising the relevant powerful influences that can seduce and enthrall others.

There have been some very notable and tragic past examples of paranoid contagion – but up until now they have been the exception that proved the rule. Those exceptions, however, had the same factors at play as we now see to be more widespread.  While the past outbreaks were more isolated and time-limited, they were nevertheless very damaging. If you like, it was like the Ebola virus outbreaks in Africa, very dangerous and frightening but contained by rapid control measures to eliminate wider spread.

The outbreaks of contagious paranoia that we have seen in recent history have been generated and orchestrated by charismatic, persuasive, narcissistic, grandiose and paranoid leaders. Some of them have organised their ideas within a religious framework, others in a more ideological political structure. These men have fed the insecurities, resentments and unmet desires of the people who became their followers, taking on the fervour and paranoid fanaticism of the leaders. Immersed in the emotions and drives of the leader’s movement, they became increasingly isolated and unable to recognise the destructive pathway down which they were being willingly led.

 The process that they were subjected to was initially subtle, based on some real issues or resentments in society, then gradually increasing in range, intensity

and momentum, playing on and exploiting their vulnerabilities until they felt there was no other path but to follow the leader.

This is the kind of process that resulted in the tragedies of the Waco siege; the Jonestown massacre, with the induced suicide of more than 900 disciples; and the Holocaust, where Hitler used his paranoid persuasive powers to influence a whole population to at least acquiesce and many members to actively collaborate in the murder of six million Jews, artists, homosexuals and disabled people. These few examples illustrate the possibility of the transmission of paranoia from one very deeply disturbed individual to many future disciples, through the exploitation of people’s fear, suspicion, resentment and despair.

There is a distinction to be drawn between these examples of contagious paranoia occurring as a distinct departure from their societal settings and other examples where, in a broad socio-cultural context, widespread fear and suspicion is the result of actions by governments and powerful leaders. Paranoia about the enemy is routinely highlighted and enhanced by Governments in wartime, to legitimize the sanctioned aggression necessary to further the goals of the protagonists. Throughout the world, there have been many examples over the centuries where despotic leaders exhibiting paranoid and narcissistic traits have expressed those traits by brutal suppression and subjugation of their subjects. No doubt those societies suffered lasting trauma, fear and resentment of authority. Suspiciousness and a degree of paranoia might well have then been handed down to future generations almost by birthright. That phenomenon is really the mass imposition of paranoid traits, different to the kind of infectious paranoia I have described in the above examples. Hitler was a leader who infected his people through malign inspiration and persuasion to carry out

a process of genocide of a targeted minority and therefore his is primarily an example of the most egregious type of contagious paranoia.

It is interesting to note that, in clinical diagnostic terms, the dangerous leaders of the ultimately self-destructive movements I have described were probably not suffering from the most severe paranoid schizophrenic illnesses, which would have been evident by florid psychosis and complete loss of touch with reality. A very severe psychosis can be recognised as bizarre by anyone close to the sufferer. Such a disturbed individual would likely be too disorganised and clearly unwell to attract and convince disciples to follow his path.

More likely, Hitler and the others had severe personality disorders with prominent paranoid and narcissistic traits and a good dose of psychopathy thrown in. They may have had some ideas of delusional depth but not severe pervasive psychosis. They had to be intelligent, persuasive, articulate and cunning to be able to achieve what they did. These same characteristics enabled them to lead their followers to eventual destruction. Such is the potential power of these paranoid disorders that clinically fall short of the most severe paranoid psychotic illnesses. These few examples of the contagion of paranoia beyond a family group were all eventually ended and contained by political and social forces that recognised lines had been crossed – but in each case not before much tragic loss of life.

These particular historical examples all occurred well before modern technology, in situations where there was no Internet, no mobile phones, no text messages and no social media. News and information was provided to the populace via mainstream print media, snail mail, in-person meetings, radio

broadcasts and newsreels at the cinema screened well after the actual events occurred. Those means of communication were all subject to editorial control and a degree of censorship. Clearly, these methods could be used by the powers-that-be in society. But it was all slower, more delayed, and more controllable than the way things are now.

Mobile telephony, the Internet and social media have brought radical change. We now have instant communication and sound bites. There is access to freedom to say or write anything and enable it to be seen immediately by hundreds, thousands or millions of people. Everyone can express their opinions, no matter what they are, with very little effective censorship. Everyone can research any topic or question that they fancy. Anyone can hold themselves up as knowledgeable and expert without any screening process, or make something up and post it as if it is gospel truth. Real news or video footage can be posted, but it can also be doctored and edited by others. Photos can be posted, distorted and faked. There is very little accountability.

The Internet and social media have not just made radical changes for individuals. These new ways of functioning have also been made available to governments. It is now possible for authorities to know almost everything about us – our health, our movements and activities. Terrorism has become a source of fear and a justification for increased surveillance by government. If the population is comfortable that this is a necessary intrusion on privacy and liberty to ensure safety, and if they feel that the government is sufficiently open and transparent, the balance may be workable. But if trust between the people and their political masters is eroded, fear and suspicion will increase, and along with that the likelihood of more paranoia being promulgated on social media.

This incredible change to the way in which ideas and knowledge are communicated and shared has led to a need to understand the contagion of paranoia and to completely re-think our understanding of paranoid disorders.

The Internet has provided a fertile ground for paranoid ideas to be promulgated, copied, elaborated and distributed. No longer is a paranoid person isolated in his or her own anxious and defensive cocoon. The walls of their existence have literally expanded from their home and immediate community to the whole world. On the Internet, their suspicions can be shared, their ideas shaped, extra dimensions can be added and their delusions can be given crystallised form, focus and validation. Paranoid suspiciousness arising from disease processes in the brain can coalesce around the latest theoretical frameworks in the quest for explanation.

We now live in an age where many people do hold prominent distrust of the prevailing institutions of Government and the rule of law. Confidence in the effectiveness of democratic systems has diminished. Trust in politicians has been eroded. Conspiracy theories arise in such an anxious environment. These various conspiracy theories provide, for paranoid individuals, a welcome framework around which they can weave their particular ideas. Ideas on the Internet that start with logic and reasonable beliefs can very well become twisted or misinterpreted and subsequently incorporated and elaborated into much more fanciful and highly illogical paranoid concepts. Validation on the Internet for paranoid ideation is seized upon as an explanation for the fears and emotions experienced as part of a paranoid disorder. Now the sufferer can see their problems as resulting from 5G or other malign influences from the

Government or other powerful leaders in society. There will be a great deal of “evidence” provided on the Internet to shore up those beliefs.

 A paranoid individual is using the psychological process of projection, placing the blame for his or her own fears onto others. People who are perceived to be powerful or influential often become the focus for this projection and they may then be incorporated into the individual’s paranoid beliefs or delusions. Thus we hear of “evil cabals” of the leaders of science, medicine, pharmacological companies and senior politicians allegedly out to destroy us all.

The Internet and social media have become tools for politicians and ordinary citizens to manipulate others for their own purposes. Manifestly false material can be spread and endlessly repeated, which makes it more and more believable for many vulnerable readers. “Fake News” becomes a pervasive thing, fear is spread and the latent anxieties and insecurities of billions of people are readily highjacked by people seeking political office or other means of power. However, what may start as some semi-legitimate and relatively harmless manipulation of the media can easily meld into increasingly outlandish and frankly paranoid exploitation, with much more dangerous potential consequences.

The Covid pandemic has come along and become a welcome hunting ground for those seeking to explain paranoid feelings or exploit the fears of others. The

whole world is feeling anxious and insecure; normal social interactions and family supports are disrupted; people are forced into isolation. But the Internet isn’t isolated. People still access news and information. Paranoid suspicions coalesce anew in regard to the origins of Covid and the reasons why

Governments use isolation and set vaccination rules. It has become increasingly difficult to clearly distinguish true research and expert opinion from fake news and manufactured distortions.

This produces a real dilemma for clinicians in diagnosing paranoid disorders that need treatment. How can we define a paranoid delusion as a true symptom and distinguish it from a socially contrived opinion or idea? The concept of a delusion being a “false, unshakeable belief not in keeping with the person’s social and cultural setting” suddenly seems rubbery and imprecise.

The most extreme conspiracy theories would be regarded by many as clearly a false set of beliefs – but if those ideas are widely promulgated on the internet and seen by a significant section of the population as in some way feasible, can they be regarded as evidence of delusional beliefs? What measure can be used to determine if an idea is not in keeping with the person’s social and cultural setting? Has the Internet worldwide community become the relevant social setting benchmark for the clinician to use in decision-making? Can the Internet itself be seen as in some respects delusional and psychotic? We have lost the traditional benchmark, but what do we replace it with?

The clinical problem is real. The devastatingly serious condition of paranoid schizophrenia still exists in our society – perhaps in one percent of us. Delusional Disorder still exists, often less obvious but potentially destructive and dangerous. Paranoid personality disorders are still prevalent. But how do

we distinguish the real clinical conditions from the manufactured copies shaped by the Internet?

Thinking about my analogy of the landscape, it is almost as if we are now looking at the mountains reflected in a lake – the high snowcapped peaks are now also seen at the bottom – this is like the Dark Web, where the most crazy ideas exist and where the true paranoid illnesses hold sway.

It is unclear whether paranoid disorders are now more prevalent than in the past. It may be that the Internet has just revealed the large number of sufferers who in past times would have been isolated and undetected, but who can now share their views with the world. It is more likely that the power the Internet has given to paranoid influences has increased anxiety and distrust in society, with more paranoid reactions being the result, through the contagion of ideas. There is also more possibility for paranoid individuals to form groups and provide escalating validity for shared paranoid ideas.

The most severe paranoid psychoses that have their origin primarily in pathological process in the brain are not likely to have significantly increased in real numbers, but they may have been revealed by their access to the Internet, whereas they would previously have been flying under the radar. Their potential is now to exert more influence on others to share their paranoid delusions.

We must remember that paranoid reactions and reversible paranoid influences can respond to education and reason and the provision of relevant supports, understanding and assistance. Increasing scientific knowledge and literacy for all of us will help in this process. If we understand how scientific research is carried out, peer-reviewed and vetted it will help us to be able to sift out the real science from the fake, and help us to understand which treatments are

legitimate and tested, rather than relying on wishful thinking and sham treatments.

To identify the serious clinical conditions we need to look closely at their evolution, the presence of any known causes and precipitants, and explore closely the presence of associated symptoms (such as hallucinations) and the overall effects of the condition on daily functions, lifestyle, relationships and personality.

As seen in the simplest example, Folie à Deux, paranoia can be infectious. Our task is to distinguish those who are the real sufferers with serious disease (who need treatment with anti-psychotic medication), from those who are secondarily, but potentially reversibly, showing the signs of infectious paranoid

reactions. The latter can eventually be assisted to recognise the world as it really is – hopefully before they get drawn into rash, illegal or dangerous behaviour at the behest of their paranoid influencers.

The earlier lessons of Hitler, Waco and Jonestown are that, at times, even the best of us can be subject to malign and damaging influences. In the age of the Internet, these influences have become much more prevalent, accessible and intrusive. We need to learn to immunise ourselves against them. We need to learn to be hard-nosed in differentiating real events from fake news, real science from fake science, real experts from charlatans; and proven treatments from wishful thinking and snake oil remedies.

We will benefit as a society if we can achieve by these means a safeguard population level of ninety percent immunity against the infectious disease that paranoia can become.

Dr Donald Grant is a forensic psychiatrist with wide experience in criminal and medico-legal practice.