November 11, 2025

expert reaction to study of patterns of nighttime smartphone use and risk of suicidal thoughts and behaviours the next day, as published in JAMA Network Open

Scientists comment on study of patterns of nighttime smartphone use and risk of suicidal thoughts and behaviours the next day, as published in JAMA Network Open

Dr Nick Ballou, Postdoctoral researcher, Oxford Internet Institute, University of Oxford, said:

“The study should be thoroughly commended for its use of detailed smartphone logs differentiated by type of use (active vs passive), considered Bayesian analyses, and investigation of a topic of key importance, late night phone use, sleep, and subsequent suicidal ideation or other thoughts. That said, there are a few aspects of the study that make me hesitant to fully accept its conclusions. One of its key predictors, Maximum Nighttime Phone-Free Gap, is grouped into 4 categories, rather than treated as a continuous variable. Several of the authors’ conclusions then focus on the difference between the 4–7 hour and 7–9 hour group, but gloss over the fact that people in the >9 hour gap group had similarly high suicidal thoughts as those with a shorter gap—undermining the idea that shorter phone-free periods are inherently riskier. These other comparisons are omitted from the headline Figure 4. I also wish the article had analyzed the reverse temporal direction – the authors acknowledge “the observational nature of our study precluded causal inference; suicidal thoughts may drive late-night phone use, not just result from it”, but could have tested this directly (i.e., predicting late night phone use from that day’s suicidal ideation, rather than looking at the subsequent day’s). More generally, this kind of study is more convincing when preregistered, as readers cannot currently know how many analyses were tried but ultimately not included – the fact that several coefficients are barely significant (see e.g., “Hourly phone use” in Figure 4) increases the risk of selective reporting leading to misleading conclusions.” 

Dr Oliver Davis, Associate Professor of Biomedical Data Science, MRC Integrative Epidemiology Unit, University of Bristol, said:

“This is important research that highlights that the impact of screen time on mental health can be either positive or negative, depending on how we’re spending that screen time. We need to understand the nuances of how best to use technology to maximise the benefits and minimise the risks.”

Prof Ben Carter, Professor of Medical Statistics, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), KCL, said:

“This study assessed the nighttime smartphone use in young to middle aged adults and the impact on health outcomes. It is a small single site study analysing self reported use. There are many methodological challenges in the study design leading to caution needed over the generalisability of the population and findings. This study should be viewed as piecing emerging evidence of nighttime (and likely bedroom use) and the associated increased risk of signs of planning or suicidal ideation. During the night rest is needed and continued smartphone use is known to impact on poor sleep.

“Public health leadership is needed to guide nighttime smartphone use, and in particular where they are used (and not used) to maximise the benefits and minimise the harms. Whilst these findings make plausible biological sense, research is needed by public funded bodies looking to assess the harms rather than the benefits of smartphone use.”

Prof Chris Ferguson, Professor of Psychology, Stetson University, said:

“This paper makes some dramatic claims linking nighttime smartphone use to suicidal ideation.  These would be alarming if true.  However, there are many good reasons for parents not to worry about this.  As the authors acknowledge, they measure phone use in crude ways. Unfortunately, more depressed people tend to overestimate smartphone use, which can cause false correlations.  Most of the effect sizes in this study look quite small, small enough they could be unreliable noise rather than true effects.  The sample size is also quite small, further reducing the reliability of the study.  The authors do not meaningfully control for other variables such as family or school stress or bullying victimization which could explain both sleeplessness and more phone use.  Parents can be assured that most studies do not find a meaningful association between any smartphone use and suicide, and one small likely unreliable study is not worth worrying over.”

* ‘Passive vs Active Nighttime Smartphone Use as Markers of Next-Day Suicide Risk’ by Ross Jacobucci et al. was published in JAMA Network Open at 16:00 UK time on Tuesday 11 November

DOI: 10.1001/jamanetworkopen.2025.42675

Declared interests

Dr Nick Ballou: Nick Ballou has worked on scientific projects funded by government grants that used data from gaming companies provided under a data-sharing agreement, but has never worked for or received funding or compensation from the tech companies or other industries connected to the work presented here. 

Dr Oliver Davis: No interests to declare.

Prof Ben Carter: I have received funding by the:

Department of education Northern Ireland to deliver a pilot study on evaluating a smartphone restriction pouch in secondary schools in Northern Ireland

The MRC assessing the impact of smartphone use on self harm 

Prof Chris Ferguson: No conflicts of interest to report.