Climate change, the responsible for temperature rise, together with floods, hurricanes, and bushfires, represents the long-term shift in temperatures and weather patterns mostly caused by human activities [UN, 2024]. Several studies have reported adverse effects of climate change on the mental health of individuals [WHO, 2023]. Climate issues have been associated with psychological distress [Austin et al., 2018], psychiatric disorders [Boscarino et al., 2014; Waite et al., 2017], increased risk for hospitalizations for psychiatric diseases [Trang et al., 2016; Wang et al., 2014; Rizzo Pesci et al., 2024], higher rates of mortality [Page et al., 2012] and suicide among people with mental disorders [Carleton, 2017; Preti et al., 2007]. Vulnerable groups, such as the youngest, people with previous mental disorders, and indigenous populations, such as the Inuit, seem to be mostly involved [Cunsolo Willox et al., 2013; Jones et al., 2012; Brophy et al., 2023].

Recently, new psychological issues linked to climate change have emerged, such as eco-concern, eco-anxiety, eco-guilt, and eco-grief [Ágoston et al., 2022b, Qi et al., 2022; Kurth and Pihkala, 2022]. At present, these conditions do not have a univocal definition. Eco-anxiety refers to the distress caused by climate change with either the appearance of anxiety related to the future or the onset of chronic fear or non-specific concern about environmental catastrophe [Coffey et al., 2021; Pihkala, 2020]. Eco-guilt has been described as the sense of guilt people experienced when they fail to meet personal or social environmental standards or when they perform activities with a negative impact on the environment [Ágoston et al., 2022b]. Finally, eco-grief was defined as the grief related to ecological loss due to environmental change [Ágoston et al., 2022b; Cunsolo and Ellis, 2018]. The relationships between eco-concerns and mental health have been assessed by a few cross-sectional studies [Schwartz et al., 2022; Searle and Gow, 2010]. Eco-anxiety was directly associated with generalised anxiety disorder (GAD) in 284 US students aged 18–35 years [Schwartz et al., 2022]. Climate change distress was found to be higher in younger and females, and it was directly related to symptoms of depression, anxiety and stress in 275 healthy adults [Searle and Gow, 2010]. In a cross-national study involving 25 countries, climate-related negative emotions (such as tension, anxiety, worry, etc.) were assessed via questionnaires using data from >11,000 participants across all continents. These emotions resulted to be associated both to self-rated mental health and predictors of insomnia symptoms in most countries [Ogunbode et al., 2021].

Recently, an increased incidence of eating disorders [Pastore et al., 2023; López-Gil et al., 2023] and orthorexia nervosa [Horovitz and Argyrides, 2023] has been reported. Eating disorders are defined as serious psychiatric disorders characterized by abnormal eating or weight-control behaviours (Treasure et al., 2020). Orthorexia nervosa is defined as “a strong preoccupation with one's eating behaviour and with self-imposed rigid and inflexible rules which are strictly controlled and include spending an excessive amount of time for planning, obtaining, preparing and/or eating one's food” (Donini et al., 2022). We hypothesized that adverse mental issues linked to ecological changes may have been involved in this phenomenon. A case of bulimia nervosa associated with eco-anxiety has been described [Runfola and Safer, 2024], and the impact of climate change on eating disorders has been proposed as an urgent topic of research [Rodgers et al., 2023]. No data about orthorexia nervosa is available at present.

The aim of the present study was, therefore, to investigate the relationships between eco-concerns and the risk of eating disorders (EDs) and orthorexia nervosa (ON) in a group of adults without known psychiatric diseases.

This was a cross-sectional study. Data was collected by questionnaires accessible by link or QR-code using social channels. The study was conducted from September 1st, 2024, to October 31st, 2024.

Inclusion criteria were as follows: age 18 to 64 years; the ability to fill in a questionnaire and to express informed consent. Exclusion criteria were age <18 and ≥65 years, self-reported history of psychiatric illnesses, including eating disorders, and treatment with psychotropic drugs.

The study protocol was approved by the Bioethics Committee of the University of Torino (number 0565135, September 27, 2024) and was in line with the declaration of Helsinki. Data were collected online and anonymously, according to the recommendations of the Association of Internet Researchers [Franzke et al., 2020]. Participants were informed about the aims of the study and about the confidentiality of collected information, which would be used for research purposes only. Participants were required to accept their data sharing and privacy policy before starting to fill in the questionnaire.

The questionnaire was distributed via social media using a link or a QR-code. Forms were submitted through Qualtrics® (Qualtrics, Provo, UT). Qualtrics® has privacy standards, including data protection.