Friendships with mentally healthy peers protect adolescents from depression, University of Warwick-led study finds
A new study led by researchers at the University of Warwick shows that having friends with healthy moods does not harm others’ mental health—in fact, it can substantially lower the risk of developing depression and increase the likelihood of recovery among teenagers.
The research analyzed social connections among high school students in the United States and applied mathematical modelling, similar to methods used to study infectious diseases, to examine how moods circulate within adolescent friendship networks. Rather than finding that depression itself spreads, the team discovered that healthy mood among peers acts as a protective and restorative influence.
Professor Frances Griffiths, head of social science and systems in health at Warwick Medical School, commented: “Depression is a major public health concern worldwide. But the good news is we’ve found that a healthy mood amongst friends is linked with a significantly reduced risk of developing and increased chance of recovering from depression.”
The research, published in Proceedings of the Royal Society B under the title “Spreading of healthy mood in adolescent social networks,” draws on data from The National Longitudinal Study of Adolescent to Adult Health. The authors examined more than 2,000 adolescents within a US high school social network, classifying individuals as having depressive symptoms (low mood) or not (healthy mood) according to clinical score thresholds.
Using a non-linear complex contagion model, the team tested whether mood states behave like transmissible traits across friendships. Their results indicate that depression itself did not spread from friend to friend. Instead, the presence of sufficient friends with healthy moods dramatically changed an adolescent’s risk profile: it could halve the probability of developing depressive symptoms over a six- to twelve-month period and could double the likelihood of recovery in the same timeframe.
Quantitatively, the model suggests that adolescents with five or more mentally healthy friends have about half the chance of becoming depressed compared with those who have no healthy friends. Likewise, teenagers connected to around ten healthy friends were estimated to have twice the chance of recovering from depressive symptoms compared with peers who had only three healthy friends.
Edward Hill, a mathematics researcher at the University of Warwick and lead author of the paper, emphasized the scale of the effect: “In the context of depression, this is a very large effect size. Changing risk by a factor of two is unusual.” He added that the findings imply that promoting friendships can be both protective and curative because having depressed friends did not appear to increase an adolescent’s risk, while healthy friends produced measurable benefits.
The study complements existing evidence linking social factors to mental health. Previous work shows that living alone, childhood adversity, and weak social support can raise the likelihood of depression, while access to confidants and social resources aids recovery. This analysis focused specifically on the influence of friendship networks on the probability of developing and recovering from depression among adolescents.
Dr Thomas House, senior lecturer in applied mathematics at the University of Manchester and co-author of the paper, noted the public health implications: “It could be that having a stronger social network is an effective way to treat depression. More work needs to be done but it may be that we could significantly reduce the burden of depression through cheap, low-risk social interventions.” He suggested practical measures—such as providing youth clubs and other opportunities for positive social interactions—that could help adolescents build friendship networks dense enough to generate protective effects.
Other research on adolescent mental health from Warwick Medical School is being highlighted in an upcoming theatre production titled Cracked, performed by Santé Theatre Warwick, which explores issues around mental health among young people.
Source: Nicola Jones – University of Warwick
Image Source: The image is in the public domain
Original Research: “Spreading of healthy mood in adolescent social networks” by E. M. Hill, F. E. Griffiths, and T. House, Proceedings of the Royal Society B. Published online August 19, 2015. doi:0.1098/rspb.2015.1180
Abstract
Spreading of healthy mood in adolescent social networks
Depression is a major public health concern worldwide. There is evidence that social support and befriending influence mental health, and a clearer understanding of the social processes that shape depression could deliver important public health benefits. This study investigates mood transmission within an adolescent social network without assuming in advance whether low mood or healthy mood spreads. The analysis shows that depression does not spread between friends; instead, healthy mood among peers is associated with substantially reduced risk of developing depression and an increased chance of recovery. Using a non-linear complex contagion model, the researchers found that having sufficient friends with healthy mood can halve the probability of developing depression or double the probability of recovering from it over a 6–12 month period. These results suggest that encouraging friendships among adolescents could lower both the incidence and prevalence of depression.
“Spreading of healthy mood in adolescent social networks” by E. M. Hill, F. E. Griffiths, and T. House in Proceedings of the Royal Society B. Published online August 19, 2015. doi:0.1098/rspb.2015.1180