In DSM-5 (the Diagnostic and Statistical Manual of Mental Disorders, 5th edition), the specifier "with absent insight/delusional beliefs" is used for Obsessive-Compulsive Disorder (OCD) when an individual is convinced that their obsessions and compulsions are not excessive or unreasonable. In other words, they lack insight into the irrational nature of their obsessions and compulsions.
The presence of this specifier suggests that the person with OCD believes their obsessions and compulsions are justified, reasonable, and accurate, even though they may appear irrational to others. The beliefs they hold about their obsessions and compulsions take on a delusional quality because they are fixed and resistant to contrary evidence or reasoning.
For example, someone with OCD who has this specifier might believe that their intense handwashing is absolutely necessary to prevent a deadly disease, and no amount of evidence or reassurance from others can convince them otherwise. They may hold these beliefs firmly, even though they may recognize that other people do not engage in the same behaviors to the same extent.
This specifier is important because it can influence the treatment approach for OCD. Individuals with OCD and absent insight/delusional beliefs might be less responsive to traditional cognitive-behavioral therapy (CBT) techniques that aim to challenge irrational thoughts and beliefs. Instead, treatment might focus more on symptom management and helping the person cope with the distress and impairment caused by their obsessions and compulsions.
It's essential to note that this specifier does not mean that the obsessions themselves have transformed into delusions. The content of the obsessions remains typical of OCD, but the person's perception of these obsessions and compulsions becomes delusional due to the lack of insight into their excessive and unreasonable nature.