Orthorexia Nervosa (ON) and exercise addiction (ExAdd) are two phenomena believed to overlap. We conducted a meta-analysis exploring the link between ON and (addictive) exercise behaviors.
A systematic review of major databases and gray literature was carried out for studies reporting on ON and (addictive) exercise behaviors. Random effects meta-analyses were undertaken calculating correlations between ON and (addictive) exercise behaviors. A sub-group analysis investigated gender differences.
Twenty-five studies with 10,134 participants (mean age = 25.21; 56.4% female) were included. Analyses showed a small overall correlation between ON and exercise (21 studies, r = 0.12, 95% CI |0.06–0.18|) and a medium overall correlation between ON and ExAdd (7 studies, r = 0.29, 95% CI |0.13–0.45|). Gender differences were negligible.
Orthorexic eating correlated slightly and moderately with exercise and ExAdd, respectively, expressing some unique and shared variance of these behaviors. While this does not suggest ON and addictive exercising to be independent, it does not indicate substantial comorbidity. Future research should focus on clinical relevance, underlying mechanisms, vulnerability, and risk factors.
Numerous studies have provided evidence for orthorexia nervosa (ON), an eating pattern characterized by an almost manic obsession for and fixation on healthy eating, to be of epidemiological relevance. However, there is scientific debate on whether it is merely a behavioral or lifestyle phenomenon as compared to a mental disorder. Aim of this cross-sectional study was to explore whether ON is of epidemiological and clinical relevance, and whether ON can be distinguished from other mental health disorders and healthy lifestyle features.
An online survey including a measure of orthorexic behaviors [Duesseldorf Orthorexia Scale (DOS)], well-being and distress, eating behaviors, pathological eating, anxiety and depression, addictive behaviors, obsessive–compulsive symptoms, personality, and health behaviors was completed by 713 subjects (79.8% women, 18–75 years, median age: 25 years).
Twenty-seven subjects (3.8%, 21 women) showed significant orthorexic eating (DOS ≥ 30). ON cases reported lower well-being, lower satisfaction with life, and higher current stress levels than non-ON cases. The highest percentage of variation in ON was explained by pathological eating (R2 = .380), followed by eating style, Mediterranean diet, compulsive symptoms, and subjective social status. Importantly, ON provided hardly any additional predictive value for well-being when also considering pathological eating.
Discussion and conclusions
Our data confirmed the epidemiological and clinical relevance of orthorexic behaviors, but the strong conceptual overlap with other mental health problems and pathological eating raise initial doubts as to whether ON is a distinct mental health disorder category. This co-occurrence, unique symptoms, and underlying processes need further exploration by comparing ON cases with patients with other mental disorders.
Problematic pornography use can be conceptualized as an impulse control disorder or alternatively as a behavioral addiction. Stress is an important trigger in addiction, but less is known about the neural effect of stress in problematic pornography use. Therefore, we aimed at investigating the effect of stress during the anticipation and viewing of sexually explicit material while considering person characteristics related to potentially being at risk for developing problematic pornography use.
In an fMRI study (n = 157 men, age: mean = 25.46, SD = 4.11) we used a sexual incentive delay task. A social stress test was used to induce stress in half of the participants. Salivary cortisol was repeatedly measured and person characteristics were considered moderating the effects of cortisol response.
We found no group differences in the neural responses during the anticipation phase, but a higher reactivity to sexual stimuli in the dACC in the stress group. Acute stress activated a pronounced cortisol response, which positively correlated with neural activations in the reward system (NAcc, dACC) to sexual cues. Further, the individual time spent on pornography use moderated the effect of cortisol in some regions of the reward system (dACC, mOFC).
Discussion and conclusions
Our results suggest that acute stress related increases in cortisol can enhance the incentive value of cues announcing sexual stimuli. This might explain why acute stress is considered a trigger of pornography use and relapse and why individual stress response might be a risk factor for developing a problematic pornography use.
The use of pornography, while unproblematic for the majority, can grow into addiction-like behavior which in its extreme form is labeled as compulsive sexual behavioral disorder in the ICD-11 (WHO, 2018). The aim of this study was to investigate the addiction-specific reactivity to cues in order to better understand underlying mechanisms in the development of this disorder.
We have used an optimized Sexual Incentive Delay Task to study brain activity in reward associated brain areas during an anticipation phase (with cues predicting pornographic videos, control videos or no videos) and a corresponding delivery phase in healthy men. Correlations to indicators of problematic pornography use, the time spent on pornography use, and trait sexual motivation were analyzed.
The results of 74 men showed that reward-related brain areas (amygdala, dorsal cingulate cortex, orbitofrontal cortex, nucleus accumbens, thalamus, putamen, caudate nucleus, and insula) were significantly more activated by both the pornographic videos and the pornographic cues than by control videos and control cues, respectively. However, we found no relationship between these activations and indicators of problematic pornography use, time spent on pornography use, or with trait sexual motivation.
Discussion and conclusions
The activity in reward-related brain areas to both visual sexual stimuli as well as cues indicates that optimization of the Sexual Incentive Delay Task was successful. Presumably, associations between reward-related brain activity and indicators for problematic or pathological pornography use might only occur in samples with increased levels and not in a rather healthy sample used in the present study.