Obsessional slowness in Down's syndrome

Obsessional slowness was originally described by S. Rachman in 1974. His patients had obsessive-compulsive disorder (OCD) and spent hours performing daily routines such as bathing, dressing and eating. Although some ritualistic behaviours were seen, slowness was the most prominent problem for these patients. Subsequently, a number of similar case reports emerged. In 1994, R. J. Pary described a small number of patients who had both obsessional slowness and Down's syndrome (DS). Apart from this, only one other report of slowness symptoms in people with developmental disabilities has been found in the literature, and this individual also had DS.

In the present exploratory case series report, 11 individuals with DS and slowness are described based on a retrospective chart review. Descriptive data and four case vignettes are presented.

The 11 individuals with DS were described as spending hours engaged in usual daily routines. Several individuals had tics, hypothyroidism and periods of freezing. Although some ritualistic behaviours were described, slowness was seen to occur in the absence of these, and often without manifest anxiety.

Obsessional slowness may be a severe variant of OCD. Although it appears to occur infrequently, there may be an elevated rate in people with DS. The current report is severely limited in scope since the case descriptions were based on a retrospective review. However, because of the paucity of published information about this clinical phenomena, it was felt that the case series might serve to establish the need for further, more systematic, prospective evaluation of individuals with DS and clinically significant slowness.