This study is novel in its assessment of a broad range of variables that relate not only to psychopathology, but also to young people’s experiences of COVID-19, the impact on their learning and relationships, as well as a range of lifestyle factors, including sleep, exercise and screen time. To our knowledge, existing adolescent studies focus on the mental health impact of the pandemic on young people (e.g. [12, 18, 19]) or lifestyle factors (e.g. ) or worry, concern and behaviour change related to COVID-19 (e.g. ), but not these factors collectively. Assessing these variables in the same sample is necessary to form a rich and complete picture of the disruption to young people’s lives, mental health and well-being. The benefit of this approach is demonstrated by our findings; for example, we demonstrate, for the first time, that the use of technology for the purposes of social connection (rather than just technology use per se) is associated with a greater sense of well-being and lower levels of loneliness. This important advance in knowledge can help guide the way teenagers can be encouraged to use technology to maintain social connection, when face-to-face interactions are not possible.
The results of our study also showed that adolescents with a self-reported history of depression or anxiety experienced heightened levels of loneliness, greater trouble sleeping, more uncertainty about the future, higher levels of health anxiety, greater psychological distress and lower levels of well-being, relative to those without a depression or anxiety history, in response to the pandemic. The proportion of participants reporting a history of depression or anxiety was comparable to lifetime prevalence estimates for adolescents , suggesting respondents were broadly representative of the general population in terms of psychiatric history. This is the first finding to indicate that Australian adolescents with a history of depression or anxiety experience greater levels of psychopathology and disruption to daily life in response to a crisis; in this case, the COVID-19 pandemic. Moreover, these results are consistent with findings examining adolescents in Canada  and adults in Australia and the US [5, 6], which collectively suggest that a history of mental illness is a vulnerability factor for deterioration in mental health during the pandemic.
There are important implications that follow on from this finding. First, from a practical perspective, the knowledge that challenges, such as a pandemic, lead to an exacerbation of mental illness among those with a history of anxiety and/or depression suggests that psychological treatments for these disorders could incorporate symptom management plans for challenging situations likely to exacerbate symptoms, as a component of therapy. Moreover, an immediate and much needed policy change is needed to expand existing mental health services for young people. There has already been an increased burden on these services  and for services to continue to provide care to young people with exacerbations in existing mental health problems, while simultaneously supporting those presenting to services for the first time, an expansion of such services is imperative. Evaluations of the impact of the pandemic on existing services and their response to the crisis (e.g. [42, 43]) may guide such an expansion and inform policy to deal with future periods of increased mental health service need. Similarly, the placement of clinically trained staff into schools to support students either face-to-face when possible, or via telehealth when not, would do much to reduce the burden on external services. Finally, another method to reduce overburdening existing services is to consider the use of effective digital mental health interventions, and blended modalities that combine digital with clinician support, which will likely improve the efficiency with which young people with mental health problems can be supported . In the longer term, a greater focus on the prevention of mental illness and upskilling young people with effective strategies to manage their mental health, especially at times of vulnerability, will have a downstream impact on ensuring services do not become overburdened, particularly during times of crisis. Taken together, the findings reported in this study underscore the need for a proactive mental health response to support young people through this tumultuous and disruptive time in their lives, through changes at both the practice and policy level.
Although respondents had little direct or indirect experience with COVID-19, more than three quarters were worried about contracting the virus, replicating findings with adults  and adolescents . Most young people believed they could reduce their risk of contracting COVID-19 and engaged in behaviors to lower their risk (e.g. handwashing and social distancing), in contrast to common portrayals by the media suggesting young people are not compliant with restrictions (e.g. ). Our results showed that worry about contracting COVID-19 was associated with greater levels of overall behaviour change, demonstrating a practical benefit of some degree of worry.
This study also sheds light on the disruption and impact of the pandemic on young people’s lives. Almost the whole sample (> 95%) had engaged in online learning, and most reported a negative impact. At the time our survey was undertaken, schools and families had to adapt to online learning from home with little-to-no preparation time. While meta-analyses have shown that with optimal delivery and support, online formats can be as effective as face-to-face in terms of learning outcomes for adults , there is no evidence to suggest this is the case for young people. Indeed, because school education is primarily face-to-face, data about the effectiveness of online schooling is lacking. Online learning requires a greater level of independence, motivation, and discipline than classroom learning, and these are skills which young people may not have fully developed .
Participants reported a negative effect of the pandemic on friendships, and feelings of loneliness, which were associated with higher psychological distress and lower well-being. Adolescents are at a crucial stage of development involving the formation of a sense of self and identity through shared interests and values with their peers . Given a lack of social connection has negative consequences on social and cognitive development , and loneliness increases the risk of the development of depression and other disorders , mental health prevention and intervention efforts need to focus on improving social connection, particularly in areas that have containment measures in place for prolonged periods. Until restrictions are lifted, the use of technology to connect with others might mitigate the potential disruption to adolescents’ social needs. With widespread smartphone use , it is reassuring that studies have found that core components of quality face-to-face interactions can be replicated online . Consistent with expectations, our study found that nearly three quarters of participants reported increased use of technology to connect with others and this was associated with lower levels of loneliness and a greater sense of well-being. This finding aligns with research from China showing increased smartphone and social media use at the height of the pandemic . Most adolescents in our study reported spending about 4 h a day connecting with others online. Whether this will mitigate potential long-term consequences of social deprivation associated with lockdowns will need to be addressed by future longitudinal studies.
Most respondents indicated that the pandemic had increased stress levels within their family and half reported an impact on the job of a parent or carer. Viewed in this context, together with adjusting to online learning and the requirement for parents to manage their own professional responsibilities with caring and supporting their child’s learning, it is not surprising this has been a stressful time for families . This aligns with findings from around the world that are beginning to highlight higher levels of stress and mental ill-health experienced by certain sub-groups of the population, including women, who are more likely to be in caring roles, as well as parents and young people [3, 7]. Despite this increased family stress, > 50% of adolescents indicated that their relationships with family members had remained unchanged, and an additional 18.7% reported an improvement; something that has not previously been found in an adolescent sample. It could be the case that in some families, more time at home with family members has some advantages, and feeling more connected to loved ones is a benefit of COVID-19 that has been found in adults .
Encouragingly, > 50% of the adolescents continued with or increased their regular levels of exercise. There are well-documented links between exercise and reduced risk of depression and anxiety across the lifespan  and the relationship between exercise and lower levels of psychological distress and great well-being in our sample is consistent with this broader literature . Given that even the strictest lockdowns in Australia have allowed for up to 1 h of exercise per day, exercise could be promoted in public health campaigns to prevent deteriorating mental health should the lockdown and period of restrictions continue. Relatedly, a significant proportion of adolescents also reported increased difficulty sleeping, and exercise is one way in which sleep quality and duration can be improved , which was supported by our correlational analyses.
Of concern was that about half of the sample reported a worsening in their physical health, since the pandemic began, while 75% reported a negative effect on their mental health. The worsening of mental health in our sample was markedly consistent to that of a recent adult Australian survey , which found that 78% of their respondents had reported worsened mental health. Overall, adolescents reported greater psychological distress and lower levels of well-being relative to normative data available from population surveys conducted prior to the pandemic [55, 56], with rates of psychological distress indicative of probable mental illness increasing almost twofold from 24.3% before the pandemic , to 48.3% in this survey. This finding accords with studies from China and Germany showing elevated mental illness in young people [8, 19]. It is important to note that the K6 is not a diagnostic interview and so without information about the exact duration of the symptoms, degree of interference in daily life and distress to the individual, drawing diagnostic conclusions is not possible. We also cannot rule out the heightened levels of psychological distress as being at least in part attributable to sampling bias, inherent with online surveys. With these limitations in mind, our data nonetheless suggest that there are significantly elevated rates of psychological distress , providing insight into the acute effects of the COVID-19 pandemic on adolescent mental health.
There are several study limitations. First, as a convenience sample recruited online due to the ease of rapid administration, 72% were female, limiting the generalizability of findings to the broader adolescent population. The importance of sampling approach has been noted as a key concern during COVID-19 . Follow-up studies should use diagnostic assessments, to provide an independent assessment of mental health. The study was cross sectional and so causal conclusions cannot be drawn.
Despite these limitations, this study has provided insight into the impact of the COVID-19 pandemic on multiple facets of young people’s lives. Marked deterioration in the mental health of adolescents, evidenced by three quarters of respondents reporting a negative impact of the pandemic on mental health and almost half reporting psychological distress levels indicative of a probable mental illness (a twofold increase from pre-pandemic levels), emphasises the need for adequate infrastructure to support the mental health and recovery of this already vulnerable population. This study showed worse outcomes for those with pre-existing mental health conditions, further indicating the need for adequate services during times of crisis, but also the need for current treatments to provide young people with skills to manage their mental health during times of adversity.