Global intrusive thoughts: A commentary

The main aims of this huge unprecedented multi-national study of intrusive thoughts were to ascertain the prevalence of the phenomenon, determine whether it is dimensional or categorical in nature, and the extent to which the thoughts reflect cultural differences. The answers to the first two questions were clear. Intrusive thoughts are extraordinarily prevalent and dimensional in nature. There were several national differences, especially in the frequency of certain thoughts, notably sexual and religious. However, the means of dealing with the thoughts were similar across countries. The use of a standardized interview for collecting the key information is a methodological advance but has limitations. Some gaps in current information about the intrusions are noted and six suggestions for further research are set out. & 2014 Elsevier Inc. All rights reserved. The occurrence of intrusive thoughts is intrinsically interesting, and also has important implications for understanding obsessions. Intrusive thoughts interrupt the stream of consciousness and also can interrupt or disrupt ongoing behaviour. Most of the interruptions of the stream of consciousness are not too significant and are easily dismissed; they are transient. However, if the thought carries personal significance – if the person interprets it as being personally unacceptable or repugnant – it is disturbing and likely to return. For example, the thought of harming a vulnerable person, child or adult, is unacceptable and repugnant. Attempts to control the thought or block its recurrence are difficult. These uninvited, unwanted, and recurrent intrusive thoughts are the bedrock of clinical obsessions. Not all uninvited thoughts are unacceptable. Some are pleasant, some amusing, and some can be creative. For example Mozart and Beethoven described how some of their musical thoughts “intruded”. Mozart's often arrived fully formed, and Beethoven had many that “pounded into his head.” The phenomenon of intrusive thoughts became a subject of considerable attention in the 1970s during the search for an explanation for obsessions. The treatment of observable compulsive behaviour, the other manifestation of OCD, had progressed well; but obsessions presented an awkward problem because of the barrier to studying patients’ thoughts. Under the shadow of radical behaviourism, which regarded thoughts as “private events”, not observable and outside the remit of scientific psychology, obsessions were inaccessible. Attempts to explain obsessions as maladaptive conditioned responses, and related approaches, floundered. The infusion of cognitive construals enabled a fresh approach. The early research by de Silva and Rachman carried out at the Institute of Psychiatry, London University, on patients with OCD led to the recognition that the content of some obsessions resembled common intrusions, and it was postulated that unwanted intrusive thoughts are commonly, perhaps universally experienced (Rachman & de Silva, 1978). Their studies on patients with OCD and on non-clinical participants supported the proposition and it was subsequently replicated with other samples (e.g., Salkovskis, 1985). This proposition was used as the basis for a cognitive theory of obsessions in which it was proposed that obsessions arise when a person seriously misappraises the personal significance of their intrusive thoughts/images/impulses (Rachman, 1997, 1998). Obsessions arise when a person misappraises intrusive blasphemous thoughts or unacceptable thoughts of harming people or unacceptable sexual thoughts as revealing very important and disturbing aspects of their personality and values. The intrusions misinterpreted by patients as revealing were classified as a trio: they mean that I am “bad, mad, dangerous” or a mixture of the three (Rachman, 2003). The affected person recognises that the thoughts are their own products (not inserted thoughts) and they reject and resist them. According to the cognitive theory, the recurrence of obsessions is explained by the persistence of the maladaptive misappraisals of the significance of the intrusions. When these appraisals are replaced by benign realistic appraisals the obsessions do not recur (Whittal, Woody, McLean, Rachman, & Robichaud, 2010). Obsessions can be thoughts, images or impulses, but the early research concentrated primarily on thoughts. This limitation is now being corrected by the surge of research into images; these powerful cognitions arise fully formed and are astonishingly stable and exceptionally upsetting (Rachman, 2007). It is regrettable that because of the timing of the Global study, prior to the surge, the prevalence and continuity of intrusive images were not studied in detail.