Notes

This book gives general information. It isn't medical or psychological advice, and it's no substitute for a doctor or therapist who knows your situation.

I've kept sources out of the chapters so they read easily. Here they are by chapter, with the limits I'm aware of. Where a chapter isn't listed, it rests on my own reasoning. That includes the split between the concern and the worrying in chapter 1, the list of payments and costs in chapter 2, the alarm and the pen test in chapter 3, the argument about unworried events in chapter 5, and all of chapter 9.

A general caution applies to most of what follows. Much of the research on worry has been done with people who have generalised anxiety disorder, or with students who score high on worry questionnaires. I've applied it to everyday worrying. I think that's reasonable, since the studies that included both ordinary and severe worriers mostly found the same patterns in each. But it is a step beyond what the studies tested.

Chapter 2. The reasons people give for worrying are from Borkovec and Roemer, "Perceived functions of worry among generalized anxiety disorder subjects", Journal of Behavior Therapy and Experimental Psychiatry 26, 1995, pages 25 to 30. The participants were students. The group with severe worry stood out for a further reason, which was that worrying distracted them from more emotional topics. The finding that worry is mostly thoughts and not images is from Borkovec and Inz, "The nature of worry in generalized anxiety disorder: a predominance of thought activity", Behaviour Research and Therapy 28, 1990, pages 153 to 158. The idea that worry works as a way of avoiding emotional imagery is offered in that paper as a speculation. It has been developed since but it remains a theory.

Chapter 3. Watkins, "Constructive and unconstructive repetitive thought", Psychological Bulletin 134, 2008, pages 163 to 206. Level of thinking is one of three factors he identifies. The other two are whether the content is positive or negative, and the person's circumstances. Llera and Newman, "Worry impairs the problem-solving process: results from an experimental study", Behaviour Research and Therapy 135, 2020, article 103759. There were 185 participants, about half of them high worriers. The drop in confidence was found only in the high worriers. The drop in rated effectiveness was found in everyone. Davey, "Worrying, social problem-solving abilities, and social problem-solving confidence", Behaviour Research and Therapy 32, 1994, pages 327 to 330. A similar result with patients is in Ladouceur, Blais, Freeston and Dugas, Journal of Anxiety Disorders 12, 1998, pages 139 to 152.

Chapter 4. LaFreniere and Newman, "Exposing worry's deceit: percentage of untrue worries in generalized anxiety disorder treatment", Behavior Therapy 51, 2020, pages 413 to 423. The summary of the paper gives 91.4 per cent of worries as not coming true, and its table gives 91.3. The average per person was 89.6 per cent. There were 26 women and 3 men. The authors list the small sample, the narrow group of participants, and the restriction to short-term worries as limits. They also note that participants judged for themselves whether a worry had come true. The authors mention two earlier counts, reported briefly by Borkovec, Hazlett-Stevens and Diaz in 1999. In one, about 68 per cent of worries didn't come true, and in the other, 85 per cent turned out better than expected. Neither went through peer review, so I haven't used them in the chapter. You may have seen the 85 per cent figure quoted elsewhere without that caveat.

Chapter 5. Freeston, Rhéaume, Letarte, Dugas and Ladouceur, "Why do people worry?", Personality and Individual Differences 17, 1994, pages 791 to 802. The description of relief as a reward for worrying, and the word superstitious, are from Borkovec's work as summarised in Newman and Llera's 2011 review, listed under chapter 6. The argument from the events you didn't worry about is mine. So is the observation that the worst events often come from an unwatched direction. I know of no study that has counted that.

Chapter 6. Newman and Llera, "A novel theory of experiential avoidance in generalized anxiety disorder: a review and synthesis of research supporting a contrast avoidance model of worry", Clinical Psychology Review 31, 2011, pages 371 to 382. It's a theory with supporting studies, and other theories of worry compete with it. Sweeny, Reynolds, Falkenstein, Andrews and Dooley, "Two definitions of waiting well", Emotion 16, 2016, pages 129 to 143. Sweeny and Krizan, "Sobering up: a quantitative review of temporal declines in expectations", Psychological Bulletin 139, 2013, pages 702 to 724. The conclusion that bracing is best left until late is my reading of the two papers together, and the authors don't put it that way. Norem and Cantor, "Defensive pessimism: harnessing anxiety as motivation", Journal of Personality and Social Psychology 51, 1986, pages 1208 to 1217.

Chapter 7. Gilbert, Pinel, Wilson, Blumberg and Wheatley, "Immune neglect: a source of durability bias in affective forecasting", Journal of Personality and Social Psychology 75, 1998, pages 617 to 638. The studies show that people overestimate how long they'll feel bad. They don't show that bad events are painless, and they didn't include the most severe losses a person can suffer.

Chapter 8. Dugas, Gagnon, Ladouceur and Freeston, "Generalized anxiety disorder: a preliminary test of a conceptual model", Behaviour Research and Therapy 36, 1998, pages 215 to 226, which compared 24 patients with 20 other people. The experiment is Ladouceur, Gosselin and Dugas, "Experimental manipulation of intolerance of uncertainty", Behaviour Research and Therapy 38, 2000, pages 933 to 941. The trial is Ladouceur, Dugas, Freeston, Léger, Gagnon and Thibodeau, Journal of Consulting and Clinical Psychology 68, 2000, pages 957 to 964. Twenty of the 26 patients no longer met the criteria after treatment. The comparison group was a waiting list, which is an easy comparison to win. The list of small uncertainties to practise on is mine, in the spirit of their treatment.

Chapter 10. The twin study figure is from Hettema, Neale and Kendler, "A review and meta-analysis of the genetic epidemiology of anxiety disorders", American Journal of Psychiatry 158, 2001, pages 1568 to 1578, which put the heritability of generalised anxiety disorder at 0.32. The authors say the part played by family environment is uncertain. McGowan and Behar, "A preliminary investigation of stimulus control training for worry", Behavior Modification 37, 2013, pages 90 to 112. The original is Borkovec, Wilkinson, Folensbee and Lerman, "Stimulus control applications to the treatment of worry", Behaviour Research and Therapy 21, 1983, pages 247 to 251. Wegner, Schneider, Carter and White, "Paradoxical effects of thought suppression", Journal of Personality and Social Psychology 53, 1987, pages 5 to 13. The later analysis is Abramowitz, Tolin and Street, Clinical Psychology Review 21, 2001, pages 683 to 703.

Chapter 11. The worry slot is the stimulus control method above. The log is a simplified form of the worry outcome journal used by LaFreniere and Newman. The question about whether there's a step is a common tool in cognitive behavioural therapy, where it's often drawn as a diagram called a worry tree. Writing down the worst, the most likely and what you'd do is also standard practice in that therapy. Plans in "when, then" form are from Gollwitzer and Sheeran, "Implementation intentions and goal achievement", Advances in Experimental Social Psychology 38, 2006, pages 69 to 119. The six-part method as a whole is mine and hasn't been tested as a package by anyone.

Chapter 13. Worry about worry is a central part of Adrian Wells's account, set out in "Meta-cognition and worry: a cognitive model of generalized anxiety disorder", Behavioural and Cognitive Psychotherapy 23, 1995, pages 301 to 320. The advice on when to seek help follows the NHS page on generalised anxiety disorder and the National Institute for Health and Care Excellence guideline CG113, "Generalised anxiety disorder and panic disorder in adults: management", published in 2011 and last updated in 2020. Both are written for England, and services differ elsewhere. The advice about getting out of bed when you can't sleep is a standard part of behavioural treatment for insomnia.