Devi Sridhar warns phones have insidious impact on mental health even without social media
When Prof Devi Sridhar began teaching at Oxford in 2005, she held “office hours” a couple of times a week – literal time set aside for students to drop by and talk. Emails were formal and rare, reserved for matters that could not wait until a face-to-face conversation. Fast forward to 2026, and that pattern has been upended. Office hours have been replaced at many universities by a relentless stream of emails and Teams messages, with responses expected within hours or even minutes. The line between evenings, weekends and normal working hours has dissolved. The result, Sridhar observes, is that a single notification on her phone or laptop – before she even reads it – sends her stress levels rising. Modern communication, she argues, is pushing our minds to the limit, and not because of social media alone. Even older forms of digital messaging trap us in an “always on” way of being that our brains were never designed to handle.
From structured time to constant ping
The shift Sridhar describes is not unique to academia. Across the workplace and personal life, the expectation of instant replies has become normalised. The same technology that allows us to be in touch at any hour also erases the boundaries that once protected personal time. Every notification demands a small decision: respond now, later, or forget it? Multiplied by dozens of interruptions each day, this constant task-switching leads to cognitive fatigue and emotional exhaustion. Research cited in the briefing notes that it takes an average of 23 minutes to fully return to a task after an interruption – and most people experience multiple interruptions per hour. The prefrontal cortex, crucial for focus and decision-making, becomes overloaded by information from devices, producing mental fog and reduced clarity.
Why in-person communication matters for well-being
To understand why digital interaction feels so stressful, Sridhar points to human evolutionary history. Our brains and societies did not evolve in a world of instant, virtual communication. For most of our past, communication occurred face to face within small, stable groups of no more than about 150 individuals – the number of meaningful social relationships, prominent anthropologists say, that humans can maintain. In-person interaction provides context: facial expressions, vocal tone, eye contact, body language. We learn not only from words but from non-verbal cues. Modern digital messaging strips that dimension away, leaving short, text-based exchanges that are stripped of nuance and prone to misinterpretation. Studies bear this out. A 2022 study in Boston examined various forms of communication and found that days with more text messaging were linked to greater stress and more negative feelings, while days with in-person contact were linked to feeling more positive. A 2026 review of numerous studies on the same question reached the same conclusion: well-being is consistently higher with face-to-face interaction than with screen-based communication. Technology, Sridhar notes, can be better than no contact at all, but it is not as effective as in-person meetings. People are less engaged and report fewer positive emotional responses when communicating digitally.
The stress of digital interaction: read receipts, ghosting and micro-rejection
Digital communication has introduced new sources of stress that were absent from older methods. The arrival of read receipts – the two blue ticks that signal a message has been seen – has added a layer of emotional burden. From a neuroscience perspective, delayed or ignored messages can activate the same brain regions associated with physical pain, particularly the anterior cingulate cortex and anterior insula. This is known as social pain, and it reflects how our brains respond to exclusion or rejection. When someone abruptly ends communication without explanation – “ghosting” – it can feel deeply painful. For nearly all of human history, living in small, tight-knit groups meant that disappearing from someone’s life was not an option. Modern studies show that unexplained disconnection in romantic relationships activates biological alarm systems: raised stress levels, heart rate and blood pressure, pushing individuals to restore the bond or seek an explanation. “But why did they ghost me? What did I do?” Without a narrative, the brain has no way to resolve what happened.
Even shorter periods of being left “on read” – seeing that a message has been read but receiving no reply – can trigger feelings of micro-rejection. The brain is primed to detect tiny shifts in social availability, and this can be especially hard for those who already suffer from low self-esteem. A parallel group feels the pressure to reply quickly, especially when they have been seen online or their message marked as read. The ability to see when someone is typing or last online has intensified the sense that one must always be present, to avoid appearing rude or emotionally distant. Research indicates that a significant proportion of people feel ignored or anxious when their read messages are not responded to; some studies suggest people feel worse more quickly when waiting for a response to a “read” message than one left unread.
Cognitive overload and the toll on mental health
The constant availability demanded by digital tools has measurable consequences. Every notification represents a small decision, and the cumulative effect is cognitive fatigue and emotional exhaustion. Sridhar notes that study after study documents high rates of burnout, exhaustion and loneliness – not just in the UK but globally. We are more in touch than ever, yet more lonely and stressed than ever before. The UK, in particular, faces a loneliness crisis. The Global Mind Project ranked the UK 70th out of 71 countries for mental well-being, highlighting the depth of the problem. Loneliness is linked to increased risks of premature death and major health problems, and new data suggests that people reporting poor mental health are five times more likely to feel lonely than those with good mental health. Sridhar, who chairs global public health at the University of Edinburgh and directs the Global Health Governance Programme, argues that our nervous systems were designed for immediate, tangible threats – not for the constant ping of a notification in our pocket, nor for the stress of being left unread.
