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Day # 94: Review Quiz -> Obsessive Compulsive Disorder (OCD)

Today will be our first review quiz for the OCD theme. Take a few minutes and check your retention.

1) Which of the following is required for the diagnosis of obsessive compulsive disorder (OCD)?

a) Presence of obsessions and compulsions

b) They must recognize that their obsessional thoughts are not true

c) Symptoms must be present for >6 months

d) Symptoms must be time-consuming or cause significant distress or impairment

2) According to current research, which of the following neurotransmitters plays the least consequential role in the pathophysiology of OCD?

a) Serotonin

b) Norepinephrine

c) Dopamine

d) Glutamate

3) Which of the following is a predictor of good prognosis in OCD?

a) Presence of a precipitating event

b) Onset of symptoms during childhood

c) Co-existing MDD

d) Bizarre compulsions



Question 1:

From day #90

Answer: d

a) Presence of obsessions and compulsions (FALSE: presence of obsessions or compulsions or both)

b) They must recognize that their obsessional thoughts are not true (FALSE: can have varying levels of insight)

c) Symptoms must be present for >6 months (FALSE: no exact timeline specified in diagnostic criteria)

d) Symptoms must be time-consuming or cause significant distress or impairment (TRUE)


Obsessive Compulsive Disorder (OCD)

  • Presence of obsessions or compulsions or both.

  • Obsessions = thoughts/urges/images that are recurrent/intrusive/undesired and cause distress/anxiety.

  • Compulsions = repetitive behaviors/mental rituals that the individual feels driven to perform (often in response to obsessions) aimed at preventing or reducing anxiety/distress.

  • Time consuming (ex: take >1 hour per day) or cause significant distress or impairment (ex: social or occupational).

  • Symptoms are not attributable to a substance/medication or another medical or mental disorder (such as MDD, GAD, autism, etc...).


  • Insight: Individuals with OCD have varying levels of insight regarding their symptoms. They may recognize their obsessions/compulsions to be definitely not true or they may be convinced that they are true. This can be specified as good/fair insight, poor insight, or absent insight/delusional beliefs.

  • Tic-related: Up to 30% of individuals with OCD have a lifetime tic disorder. This is most common in males with onset of OCD in childhood.

Question 2:

From day #91

Answer: b

Currently, there is less evidence for dysfunction of norepinephrine.


Pathophysiology 1

  • Neurotransmitters: dysregulation of serotonin is hypothesized and most of the supporting data is from clinical drug trials. Data shows that serotonergic drugs are most effective in treating OCD. Past research also shows glutamate and dopamine involvement. Currently, there is less evidence for dysfunction of the noradrenergic system.

  • Neuroanatomy: numerous lines of research support a role for cortico-striatal-thalamo-cortical (CSTC) circuits in OCD. Dysfunction in the orbitofrontal cortex, anterior cingulate cortex, and striatum (caudate nucleus, putamen, and globus pallidus) have been most strongly indicated. These findings have been supported by brain imaging studies (structural, PET, fMRI) and neurosurgical treatment. See this article for a more thorough review.

Genetic 2

  • Significant genetic component with higher rates of OCD in first-degree relatives (3-5 times higher than the general population). Even higher risk among relatives with onset in childhood or early adolescence.

  • Higher concordance rate in monozygotic (0.57) vs dizygotic (0.22) twins.

  • There is also a higher rate of OCD in first-degree relatives with Tourette's disorder.

Other known risk factors include:

  • Childhood maltreatment: correlation with physical, sexual, and emotional abuse. Known risk factor for many psychiatric conditions.

  • Infectious / Autoimmune: some children may develop acute onset obsessive-compulsive symptoms in the context of infection with group A streptococci or other triggers (viral infections, drugs, or metabolic abnormalities). These conditions are known as PANDAS (pediatric autoimmune neuropsychiatric disorder), PANS (pediatric acute-onset neuropsychiatric syndrome), or CANS (childhood acute neuropsychiatric symptoms). We will discuss these topics later in this theme.

  • Temperament / Personality: certain traits are possible risk factors and include behavioral inhibition (tendency towards distress/nervousness/withdrawal in new situations) and higher negative emotionality.

Question 3:

From day #91

Answer: a

The presence of a precipitating event is a good prognostic factor for OCD. All others listed are predictors of poor prognosis.


Course and Prognosis 3

  • Onset: typically gradual, but sudden onset of symptoms can be seen. Some sources even report that more than half of patients with OCD have sudden onset of symptoms that first occur after a stressful event (ex: pregnancy, death of relative).

  • Course: a chronic course, spanning over several decades, with waxing and waning symptom severity, is typical of OCD. In contrast some patients do have an episodic course (~25% of cases according to one study 5) where symptoms are only present during an episode and during the remaining time symptoms remit with or without treatment. It is unclear what the symptom-remission interval should be to qualify for an episodic course in OCD.

  • Prognosis: spontaneous (untreated) remission rate among adults is ~20%. With treatment ~20-30% have significant improvement in their symptoms and 40-50% have moderate improvement.

  • Predictors of poor prognosis: yielding to (rather than resisting) compulsions, onset of symptoms during childhood, bizarre compulsions, the need for hospitalization, coexisting MDD, delusional beliefs, and coexisting personality disorder (especially schizotypal).

  • Predictors of good prognosis: good social/occupational adjustment, the presence of a precipitating event, and episodic nature of symptoms.


Nice work. If you want to see all of the weekly quizzes you can see them here. Next lesson we will cover treatment of OCD.

If you are looking for more reading material then check out our recommended resources.

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