CHAPTER 19 Obsessive-Compulsive Disorder
Obsessive-compulsive disorder (OCD) is characterized by obsessions, compulsions, or both (Table 19-1). The most common obsessions are fears of contamination, repeated doubts, need for orderliness, aggressive or horrific impulses, and sexual imagery. The most common compulsions are handwashing, ordering, checking, requesting or demanding reassurance, praying, counting, repeating words silently, and hoarding. Compulsions predominate in children, who often do not complain about the symptoms because they frequently have less insight than adults. In some cases, children show some voluntary control or may hide the symptoms, which may shift over time.
TABLE 19-1 Criteria for Diagnosis of Obsessive-Compulsive Disorder
Obsessions are defined by (1), (2), (3), and (4)
Prevalence of OCD in children and adolescents ranges from 1% to 4%, increasing with age. Nearly 80% of adults with OCD had symptoms in childhood. OCD is more common in boys at a younger age and in girls during adolescence. Family studies reflect a genetic component in OCD, with monozygotic twins affected more commonly than dizygotic twins. OCD may be related to group A streptococcal infection and is referred to as pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections (PANDAS). The onset of PANDAS is often before puberty. It is frequently associated with neurologic abnormalities.
The overall lifetime psychiatric comorbidity, including tic, mood and anxiety disorders, disruptive behavior (attention-deficit/hyperactivity disorder [ADHD] and oppositional defiant disorder), and specific developmental disorders, is as high as 75% (8% to 73% for mood disorders, and 13% to 70% for anxiety disorders). There are strong relationships between OCD, Tourette’s disorder, body dysmorphic disorder, hypochondriasis, obsessive-compulsive personality disorder, and PANDAS.
No laboratory or imaging studies confirm or disprove the diagnosis. Physical examination may reveal rough, cracked skin as evidence of excessive handwashing.
The differential diagnosis for OCD includes psychotic disorders, other anxiety disorders, and obsessive-compulsive personality disorder. Obsessive-compulsive personality disorder is a character style involving preoccupation with orderliness, perfectionism, and control. No obsessions or compulsions are present. Body dysmorphic disorder, a delusional fixation on appearance, can be confused with OCD. Trichotillomania or hair pulling to relieve anxiety or tension also can be confused with OCD. Schizophrenia can be concurrent with OCD. Intrusive thoughts of OCD can be confused with hallucinations. Complex tics may be confused with simple compulsions such as touching oneself. Of particular importance in pediatric OCD is the high rate of comorbid tic disorders (13% to 23%), including Tourette’s syndrome (50%). Major depression, other anxiety disorders, eating disorders, and obsessive-compulsive personality disorder commonly coexist with OCD. Learning disorders and disruptive behavior disorders are also common.
Cognitive-behavioral therapy (CBT) alone is the initial treatment of choice in milder cases. High severity of symptoms and complication with comorbidities or insufficient cognitive or emotional ability to cooperate in CBT are indications for selective serotonin reuptake inhibitor (SSRI) treatment. Benefits of using CBT include the apparent durability of symptom relief and avoidance of potential pharmacotherapy-associated side effects. However, the combination of CBT and SSRI may be more efficient than either one alone.
SSRI treatment is generally thought to show a favorable risk-to-benefit ratio in OCD. Behavioral side effects such as activation, akathisia, disinhibition, impulsivity, and hyperactivity may be seen. Monitoring of height may be advisable due to possible growth suppression associated with the SSRIs. In the case of nonresponse, a second SSRI is recommended. (SSRI switching can be done quickly without a cross titration.) Failing this, a clomipramine trial can be attempted. Combinations are considered if single drug therapy fails. Antipsychotics may be needed in severe or treatment refractory cases. Tapering medication should occur during times of low stress (e.g., summer vacation). The response rate to SSRI is lower in the presence of comorbidities. These patients may also be more vulnerable to relapse with SSRI discontinuation. CBT may counter this.
For children and adolescents with OCD and comorbid tic disorder, improvement in tic severity is frequently seen with the improvement of mood and anxiety symptoms. A low dose of risperidone or another atypical antipsychotic medication may be helpful. In OCD comorbid with ADHD, it is common to combine SSRIs (or clomipramine) with a psychostimulant, even though there is theoretical risk that stimulants may increase obsessional symptoms. Intravenous immunoglobulin and other techniques aimed at the streptococcal cases (PANDAS) show promise. One should suspect PANDAS in children with an abrupt onset or exacerbation of OCD and/or tic after an upper respiratory tract infection. Antistreptolysin O, antistreptococcal DNAase B titers, and a throat culture assist in diagnosing a group A beta-hemolytic streptococcal infection.
As many as one third of young people with OCD are refractory to treatment. Many responders exhibit only partial response. Poor prognostic factors include comorbid psychiatric illness and a poor initial treatment response.