Demand for mental health treatment has been growing nationally in the UK for several years, across a range of diagnoses. Rates of mental disorders are generally higher in areas of deprivation and social disadvantage. This trend starts in children and continues into old age. Determinants of mental disorders are likely to be found in the social environment and may accumulate over the lifespan. A work by Nicholas Christakis of Yale University, published more than a decade ago, deals with dynamic social networks. Common mental health problems like depression can spread between neighbors. In slums, people can share a common experience of being insecure about basic things like food, housing or heating. In the US, Senator Bernie Sanders emphasized that 60% of Americans live paycheck to paycheck.