Depression is a hellish state of mind, far worse than just feeling down. The depressed divide into two main types. The “dependent” kind are plagued by feelings of loneliness, desperate to be comforted, nurtured and protected. The other category is called “self-critical” because they are afflicted by feelings of unworthiness, inferiority, failure, and guilt. This is the sort most commonly found in high achievers.

They are plagued by a fear of disapproval, criticism and lack of acceptance by others and are prone to harsh self-scrutiny. They may set themselves impossible standards, strive for excessive achievement and perfection, are often highly competitive and hard working, making huge demands on themselves yet never feeling lasting satisfaction even if they succeed.

Dozens of studies show that this often results from having had controlling parents.Achievement was rewarded by their extremely critical, insatiably demanding parents; high marks and outstanding performance were sought as ways to obtain love. They were more likely as children to be subjected to a torrent of negative, words like bad, stupid, inadequate, useless, unwanted. At least one in ten of all British children are exposed to such hyper-criticism.

Whereas the dependent type of depressive uses fantasies of a relationship in which they are loved to derive feelings of self-worth, glittering prizes are often the means for self-critics. The trouble is that, however much they succeed in adult life, their best is never good enough — as it never was for their parents.

The combination of this kind of parenting with the wholesale adoption of materialist values is what explains the vulnerability of high achievers to depression. A little-known body of scientific studies demonstrates that materialist values are bad for your mental health.

People who place a high value on money, possessions, appearances (social or physical) and fame are more at risk of depression, anxiety, substance abuse and personality disorders. This has been found in studies conducted in 15 different nations.

All humans need to feel secure, competent and part of a community. Materialists are less likely to feel all these. They have been shown to have low self-esteem, to feel they lack control over their lives, to feel insecure and to lack intimate relationships.

The likes of Zankel and Gallop are liable to have become isolated, joyless and empty, to feel they are only “living and partly living”, as T. S. Eliot famously put it.

Trapped on a treadmill of prize-chasing, from early childhood they have only ever looked outwards for definition. Sooner or later, however much money they have earned or however powerful they have become, their inner sense of worthlessness and impotence catches up with them.

Oliver James is the author of They F*** You Up: How to Survive Family Life. His next book, Affluenza Vaccines: How to be Middle Class, Successful and Sane, is published in September.