OCD

Question 1

OCD - DSM5

Answer 1

OCD moved from anxiety disorders to a new diagnostic category

Obsessive-Compulsive and Related Disorders:
- OCD
- Body Dysmorphic Disorder
- Hoarding Disorder
- Trichotillomania (hair-pulling)
- Excoriation (skin picking)
- Substance-induced OCD (eg antipsychotics)
- Due to another medical condition (eg stroke)

Question 2

what are obsessions?

Answer 2

1. Recurrent and persistent thoughts, urges, or images that are experienced as intrusive and unwanted and that cause marked anxiety or distress.

AND

2. The individual attempts to ignore or suppress such thoughts, urges, or images, or to neutralize them with some other thoughts or action (i.e. by performing a compulsion).

Question 3

what are compulsions?

Answer 3

1. Repetitive behaviors (e.g. hand washing, ordering, checking) or mental acts (e.g. praying, counting, repeating words silently) that the individual feels driven to perform in response to an obsession or according to rigid rules.

AND

2. Compulsions are aimed preventing or reducing anxiety or distress, or preventing some dreaded event or situation; however, compulsions are not connected in a realistic way with what they are designed to neutralize or prevent, or are clearly excessive.

Question 4

what is OCD?

Answer 4

OCD = Presence of obsessions, compulsions, or both

• Obsessions or compulsions are time-consuming (e.g. >1 h/day) or cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

Common themes:
- Cleaning: contamination obsessions and cleaning compulsions
- Symmetry: symmetry obsessions and repeating, ordering, and counting compulsions
- Forbidden thoughts: e.g. aggressive, sexual, or religious obsessions and related compulsions
- Harm/pathological doubt

Question 5

neurobiology of OCD

Answer 5

• Most information derived from fMRI studies
• Cortico-striato-thalamo-cortical (CSTC) pathway

Increased metabolic activity in:
- Orbitofrontal cortex
- Anterior cingulate cortex
- Striatum

• PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection) – acquired striatal damage
• Increased activity in caudate nucleus and orbitofrontal cortex
• Serotonergic and dopaminergic neurotransmitter systems implicated

Question 6

distress and impairment

Answer 6

• Time spent preoccupied with obsessions
• Distress at content of obsessions
• Time spent performing compulsions
• Distress at “getting stuck” on compulsions, and lost time for other activities

Avoidance of triggers, e.g.
- Contamination fears - avoiding public situations (restaurants, public restrooms), not leaving home
- Intrusive thoughts about causing harm - avoidance of social interactions
- Symmetry - can derail timely completion of school or work assignments; doesn’t “feel right”

Question 7

epidemiology

Answer 7

Lifetime prevalence: 1 - 2.3% (adults)

12-month prevalence: 0.7 - 1.2% (adults)

Mean age of onset ≈ 20 years, but
- Onset can be in early childhood
- 25% have onset by 14 years
- Onset uncommon after 35 years

• Up to 25% attempt suicide
• 60-90% have a comorbid psychiatric disorder
• Esp mood, anxiety and substance use disorders;
• Tic disorders / Tourette’s syndrome

Question 8

ddx

Answer 8

• anxiety disorders
• MDD
• psychotic disorders

not on the ddx:
- Other behaviours incorrectly referred to as “compulsive”, e.g. sexual behaviour (paraphilias), gambling, substance use disorders
- Obsessive-compulsive personality disorder – similar names but completely different clinical entities!

Question 9

OCD tx

Answer 9

• Cognitive-behaviour therapy (CBT)
• Group or individual effective
• Therapist-guided better than self-help
• Cognitive component: elicit, evaluate and restructure dysfunctional beliefs regarding intolerance of uncertainty, inflated sense of responsibility and exaggeration of the importance of thoughts and need to control thoughts.
• Behavioural component: Exposure and response prevention (ERP)

Question 10

medicatio

Answer 10

First-line = SSRI
Sertraline, escitalopram, fluoxetine, fluvoxamine, paroxetine

Second-line
Venlafaxine (SNRI)
Mirtazapine (NASSA)
Clomipramine (TCA)

Question 11

tx tips

Answer 11

• Combination of CBT and medication works better than medication alone, but not better than CBT alone, for initial symptom control
• CBT = CBT + medication (if motivated)
• Adding CBT to medication likely improves long-term outcome
• Benefits of CBT are maintained at 1 and 5-year follow-up.
• Need to educate family/friends not to reassure