Differential Diagnostic Process in the Case with SCT
Many literature data point out that SCT is in less association with
externalizing disorders (i.e. disruptive behavioral disorders), whereas
more associated with internalizing disorders (i.e. anxiety, depression)
as opposed to ADHD (2, 21 – 23). In our case, no evidence was found to
suggest the presence of oppositional defiant disorder or conduct
disorder. But, especially at the beginning of clinical follow-up, the
presence of anxiety symptoms such as not being able to go to the toilet
alone and the fear of darkness is a condition that is consistent with
the literature and is expected. However, there were no additional signs
of anxiety disorder to diagnose the patient. Depression can accompany
SCT as an internalizing symptom dimension, too. However, there was not
enough evidence to clinically diagnose the case with major depression.
The case was moving slowly and had low energy. These findings may
perhaps be confounded with the ”anergia” symptom of depression. Even if
it was accepted as anergia, the presence of ”anergia” alone would not
adequately explain the depression of the case.
It was also noted that the patient did not immediately look when his
name was called, especially around 6 years of age. Hence, a possible ASD
diagnosis was investigated in the case. However, the lack of any
findings of the case in language, social communication and empathy
fields that support ASD diagnosis has kept us away from considering ASD.
The relationship between ASD and SCT was first examined in a current
study and SCT symptoms were found to be significantly higher in
adolescent cases with ASD (24). An up-to-date study in young adults with
ASD found that one-third of these cases had high levels of SCT symptoms
(25). The coexistence of these two psychopathologies may be associated
with a possible similarity or overlap between their symptoms. Since the
”processing speed slowness” observed in SCT can also be observed
frequently in individuals with intellectual disability, it is important
to distinguish these two different psychopathological structures. For
this purpose, we wanted to measure the intelligence capacity of the
case, applying WISC-R, and finding that the patient had a normal
estimated IQ score and had no mental insufficiency.
The case has inattention symptoms that do not affect his daily
functionality. Moreover, according to both psychiatric examinations
conducted on DSM-5 diagnostic criteria and K-SADS-PL clinical
interviews, the patient had subthreshold symptoms of inattentive
presentation of ADHD. One study found that 44-54% of patients with SCT
had ADHD diagnosis, 27-35% of patients with ADHD had SCT
characteristics, and 28-46% of children with SCT present an independent
phenotype not having ADHD or depression diagnoses (26).