**2. Comorbidity**

as children develop. A thorough understanding of pediatric OCD symptoms and treatment recommendations can help ensure that children are appropriately screened, assessed, and

About 1–3% of children are estimated to carry an OCD diagnosis [3, 4]. Several studies have found that males are overrepresented in pediatric OCD populations, while females hold the majority in adult cases [5]. Male's age of onset of OCD tends to be between the ages of 5 and 15 years, while women have a bimodal distribution, either developing it during childhood or

While there are many similarities between childhood-onset OCD and adult-onset OCD, several distinguishing factors are noted. Individuals with OCD onset in childhood and early adolescence are more likely to exhibit a gradual increase in symptoms and less likely to attribute triggering events, whereas individuals who develop OCD in adulthood are likely to identify possible environmental factors such as pregnancy or job loss as well as a sudden onset of symptoms [7]. Studies have also revealed individuals with early-onset OCD are likely to have

Certain clinical features such as magical thinking, tapping/rubbing, and collecting compulsions as well as motor and vocal tics are more common in childhood OCD [7]. Comorbidity patterns may differ as well with children more often presenting with ADHD and tic disorders, while adults tend to present with mood-related difficulties [10]. Symptom clusters appear to manifest somewhat differently within pediatric and adult populations. Research has indicated five common symptom dimension groups in adults through factor analysis of the Yale-Brown Obsessive Compulsive Scale (YBOCS) (cleaning, symmetry, forbidden thoughts, harm, and hoarding) and about three groups in children based on Children's Yale-Brown Obsessive Compulsive Scale (harm/sexual, symmetry/hoarding, and contamination/cleaning) [11, 12].

Children may also not necessarily recognize the irrational nature of their OCD symptoms and may not describe their symptoms as distressing. Abstract thinking and hypothesis testing are still developing during childhood so the ability to draw conclusions or make connections between symptoms and restrictions on daily living is limited. In fact, a study exploring insight in 71 youths with OCD who were part of a larger treatment trial found significant differences in insight between age groups [13]. About 48% of preadolescents (ages 8–10) were categorized as high insight, while close to 72% of younger adolescents (ages 11–13) and 79% of older adolescents (ages 14–17) were categorized as high insight [13]. Thus, younger children may have a hard time addressing their symptoms due to the potential lack of understanding of the impact of OCD. Lower insight in children has been linked to greater OCD severity, higher parent-reported OCD-related impairments, and higher family accommodation [14]. A thorough assessment of insight in children is recommended; should a child appear to have

It may also be that children do not report beliefs around their compulsions, while adults do because the beliefs may be explanations adults give to their compulsions. In other words, if you have an urge to perform a particular task, you experience a feeling (e.g., anxiety) and you perform the motor act. Then you give in to the urge and try to explain why you performed a motor act. Adults usually try to explain their behaviors and have the language as well as

poor insight, increased involvement of family members is likely warranted.

provided with effective treatment and resources.

66 Anxiety Disorders - From Childhood to Adulthood

during pregnancy [6].

a strong family history of OCD [8, 9].

Most children who have OCD also suffer from additional mental health issues similar to their adult counterparts. Comorbidity with OCD presents considerable challenges including greater symptom severity, worse functional impairment, and poorer treatment response [2]. While studies tend to vary on percentages of comorbid conditions, they consistently demonstrate that anxiety, depression, ADHD, tic disorder, and oppositional defiant disorder are typical concerns for the pediatric OCD population [15, 16].

A recent study of 322 children with a primary diagnosis of OCD found that almost two-thirds of the sample met criteria for at least one additional diagnosis beyond OCD, with a number of comorbidities ranging up to six mental health diagnoses [16]. Only 34% of the sample presented solely with OCD. Similar to other studies, anxiety was the most common comorbidity (50%), followed by externalizing disorders including ADHD and ODD (16%), followed by depression (12%), and followed by tic disorder (11%). Adolescents (ages 14–17) in particular were most likely to have comorbid difficulties compared to preadolescents (ages 10–13) and children (ages 7–9) in particular depression, which was six times more likely [16].

Since most children who present in OCD specialty clinics will likely have co-occurring conditions, it is important that pediatric OCD assessments address the presence and impact of potential comorbidities. Decisions about treatment alterations related to comorbidities often come up as well. For example, if a child meets criteria for depression and OCD, is it necessary to have stages of treatment that address each issue separately or is it possible that CBT for OCD will address both? In fact, some studies have suggested that depressive disorders are often secondary to OCD and treating OCD as usual will typically lead to improvements in depression [15]. It is also possible that symptoms from another condition can interfere with a child's ability to absorb or tolerate therapy as usual; a child with ADHD may have trouble concentrating during sessions, whereas a child with ODD may act out during sessions. In these cases, it is particularly important to continue assessment in initial treatment stages so that any possible issues can be identified and addressed as necessary.
