More people are relying on social media – such as TikTok, Instagram, YouTube and Reddit – to learn about mental health conditions and to interact with people who have shared experiences.

These aren’t only long-familiar disorders such as depression, anxiety and schizophrenia. They also include conditions often placed under the “neurodivergent” umbrella such as autism, ADHD (attention-deficit hyperactivity disorder), Tourette syndrome and dyslexia.

For instance, on TikTok the hashtag #adhd has had more than 50 billion views.

We wanted to explore how social media platforms shape how we understand mental health. So we analysed more than 14 million posts and comments about mental health on Reddit.

We show a shift in conversations toward ADHD and autism, and away from anxiety and depression.

Our findings have important implications for how people make sense of, and seek help for, mental health problems.

A complex relationship

Social media coverage of mental health has made it more visible, with some positive effects. It has probably reduced the stigma of mental illness and increased the use of mental health services.

However, it also has downsides. It can induce or exacerbate eating disorders, can contribute to the spread of symptoms (such as tic-like behaviours), and has been attributed to the rise of questionable self-diagnoses.

Misinformation is common in social media discussions of mental health. One study found a majority of the most popular TikTok videos on ADHD were misleading. Inaccurate information about many other mental health conditions on social media is common.

Discussions change and evolve

Mental health content has not merely risen in volume. Some conditions have increasingly attracted the spotlight, others have receded from view, and the relationships among them have shifted.

In our Reddit study published last year, we found that as the largest ADHD- and autism- related communities (subreddits) became increasingly more prominent from 2012 to 2022, their content gradually became more similar, and their users increasingly overlapped.

Discussions in both communities increasingly emphasised the experiences of adults, challenges in accessing diagnostic assessments, and struggles with personal relationships.

This growing convergence of these two conditions on Reddit illustrates how social media can reshape representations of mental health.

Our latest study takes this further

In our new study, we analysed more than 14 million posts and comments from several of the largest mental health communities on Reddit.

The 14 communities we studied included those related to mood, anxiety, trauma, personality, dissociation and psychosis, as well as those focused on conditions often placed under the “neurodivergent” umbrella, such as autism, ADHD, Tourette syndrome and dyslexia.

We investigated how the people belonging to these communities and the language they used changed from 2015 to 2022.

We explored which communities became more or less closely associated over time – sharing more or fewer members and containing posts and comments with similar or different linguistic content. We also looked at whether these changes reflected shifts in the amount of attention the 14 conditions received.

Although our analysis only covered a seven-year period, it revealed a striking pattern of changes. The two diagrams show how the 14 communities were interrelated at the beginning and end of the period.

The size of the circles represents the relative size of the communities. The width of the links between them indicates how closely they were associated.

In 2015, depression and anxiety were prominent mental health communities on Reddit. They were among the most active and their members and content overlapped with those of many other communities. In this sense, they were “central” to the network.

However, in 2022, ADHD and autism communities had become most popular and prominent, displacing depression and anxiety. ADHD, autism and other neurodivergent conditions became more closely associated with other communities, and consequently more central to the network.

These analyses suggest that on Reddit the mental health landscape has been re-configured. Mood and anxiety disorders once dominated discussions. But discussions of mental health have increasingly pivoted to discussing conditions related to being neurodivergent.

Reddit users do not represent the general population; they tend to be younger, male, more educated, and have a higher income. Nevertheless, our study offers important insights into changes in mental health discussions on one social media platform over time.

Why does it matter?

The rising prominence and centrality of ADHD and autism makes them increasingly popular explanations for mental health problems. This might promote accurate self-diagnosis by people who once would not have recognised the nature of their difficulties.

However, it could also lead people to misinterpret and mislabel their experiences as ADHD and autism when there’s another explanation.

The rising prominence of these conditions on social media may also lead people to interpret mood or anxiety symptoms as signs of ADHD or autism.

Misinterpretations can lead people to pursue inappropriate diagnoses or unhelpful treatment, delaying access to the help they need. This in turn places increasing pressure on mental health services, and can lead to other conditions being overlooked.

Jemima Kang receives funding from an Australian Government Research Training Program Scholarship, an Australian Academy of Technological Sciences and Engineering Elevate Scholarship, and a University of Melbourne Helen Macpherson Smith Scholarship.

Nick Haslam receives funding from the Australian Research Council.

Mike Conway does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

It’s the word of the decade. “A major signifier of our age.” “The invisible force that shapes our lives.”

But what is “trauma”? Although it occupies the cultural spotlight, its meaning has never been hazier. Can we bring it into focus?

“Trauma” derives from the ancient Greek for wound. According to the Oxford English Dictionary, this external bodily injury meaning dates back to 1684.

Late in the 19th century, “trauma” acquired a second meaning as psychological injury. In 1894, for example, the US philosopher and psychologist William James wrote of “permanent ‘psychic traumata’”, likening them to “thorns in the spirit”.

A third, figurative meaning emerged in the 1970s. “Trauma” now referred to suffering or adverse events in general. Just as “schizophrenia” and “hysteria” originated as clinical diagnoses and later picked up new, broader senses, trauma expanded and became a metaphor.

Everyone seems to be talking about trauma. Do we know more about it? Or has the meaning changed? In this five-part series, we explore the shifting definition of trauma, why talking about it doesn’t always help, and what else can work.

Trauma in psychology and psychiatry

In the mental health disciplines, the definition of trauma has followed a winding path. In 1952’s first edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM), it referred exclusively to physical injury.

No diagnosis corresponding to the psychological meaning of “trauma” appeared until 1980, when DSM-III introduced post-traumatic stress disorder (PTSD).

DSM-III listed an array of PTSD symptoms and a definition of the kind of traumatic events responsible for them. For a diagnosis to be made, the event would have to evoke significant distress in almost everyone and be “outside the range of usual human experience”.

Controversially, later editions of the DSM loosened this criterion. For example, events that were indirectly witnessed – rather than directly experienced – came to be included. Emphasis shifted from an event’s objective severity to the subjective distress it caused. Consequently, a wider range of experiences became traumatic.

These changing rules for diagnosing PTSD point to a fundamental ambiguity in the psychiatric meaning of “trauma”. It can refer to a harmful event, as when a catastrophe is described as a trauma. But it can also name the event’s psychological impact, as when a person is said to suffer from trauma.

As a result, “trauma” awkwardly straddles the objective and the subjective, cause and effect.

Concept creep

The relaxation of the DSM’s definition of a traumatic event is an example of “concept creep” – the gradual broadening of harm-related concepts. Studies have demonstrated this trend in large historical datasets.

For example, a study by my research group shows that “trauma” came to be used in a wider range of semantic contexts from 1970 to the late 2010s. That broadening is found in general text, such as news media and fiction, as well as academic articles.

“Trauma” is also increasingly used in less emotionally fraught contexts, implying that its connotations have become milder and normalised.

Interestingly, one driver of trauma’s broadening appears to be the growing cultural prominence of the concept. Books now mention it six times more often than they did half a century ago, and in psychology articles the factor is 25. The more we talk about trauma, the more it means.

The everyday uses of ‘trauma’

The public has embraced “trauma” and run with it. As a recent review observed, “the definition of trauma is more restricted in clinical psychology and psychiatry than in common parlance”.

Studies find that people define a wider range of adversities as traumas than the DSM, stretching the concept from so-called “big-T” traumas to relatively “small-t” traumas. For example, they extend it to experiencing poor housing conditions and street harassment.

Social media is implicated in these broadened definitions. TikTok videos commonly describe minor embarrassments as traumas (for example, “I sat in chocolate and didn’t realise”) and innocuous experiences, such as mind-wandering, as signs of it.

Some of these uses are tongue-in-cheek and knowing. They poke fun at broad definitions (for example, “trauma is when you open the cookie tin to find sewing materials”). In the same spirit, participants in a recent Irish study were ambivalent about such definitions, “welcoming trauma’s de-stigmatisation but deploring its potential trivialisation”.

Benefits and costs of broad definitions

This ambivalence points to a backlash against expansive definitions, but that backlash carries risks. Trivialising trauma may be wrong, but people can be harmed by events that are not “big-T” traumatic. Those who have experienced adversity deserve compassion whether or not their experiences meet diagnostic benchmarks.

People who question the concept creep of “trauma” are sometimes accused of lacking compassion, glossing over adversity and policing language. If someone wants to describe their experience as traumatic, who are you to invalidate them?

However, some objections to the inflation of “trauma” are legitimate and grounded in compassionate concern. Holding a broad definition may harm people.

One study found that people induced to hold such a definition experienced more distress and intrusive thoughts after viewing a confronting video clip than those induced to hold a narrow one. Another showed that people who held broader trauma concepts were more distressed by an upsetting clip.

Perceiving something to be traumatic may contribute to making it so. Attributing distress to trauma implies that the injury we have suffered is enduring, indelible, overwhelming and identity-defining.

For the writer Will Self, trauma has become:

the idea that certain species of experience have the ability to injure us in lasting ways, such that we carry the wound – and, indeed, the experience itself – forever with us, often without our even knowing.

Understanding the cause of our suffering in this way – beyond our control, permanent and profoundly impactful – is the opposite of what is likely to promote recovery. It is a pattern associated with depression and hopelessness.

Another reason to resist the expansion of “trauma” is conceptual clarity. If all adversities become trauma, and all distress is ascribed to it, the concept becomes a blunt instrument. “Big-T” trauma is already widespread – three quarters of Australian adults have experienced such an event, such as a life-threatening car crash or the unexpected death of a loved one – without diluting it with small-t troubles.

Read more: New study finds 2 in 5 Australians experience traumatic events as children

The expansive view of trauma promotes the increasingly popular view that distress can be explained by adverse life experiences alone. The idea we should move from asking what’s wrong with people to what happened to them sounds humane, but it can lead to simplistic trauma determinism.

Life experiences matter, but they’re not all that matters. Only 4% of people who experience a DSM traumatic event develop PTSD, for example. Many biological, psychological and cultural factors play a role in mental ill health, not just traumatic experiences.

Questioning the expansion of “trauma” is essential if we are to avoid diluting and misusing the concept. This expansion is driven by benevolent societal trends but it has a downside. At this cultural moment, when “trauma” is everywhere, we need to think clearly and critically about it.

Nick Haslam receives funding from the Australian Research Council.