Psychopathology - OCD (Biological) Flashcards
What is OCD
Obsessive Compulsive Disorder
Characterised by unwanted, intrusive thoughts (obsessions)
Repetitive behaviours or mental acts (compulsions)
Not just about tidiness or hand-washing
Can severely impact daily life
Biological explanations for OCD
- Genetic factors
- Neural factors
Focus on internal, biological causes
Aim to understand underlying mechanisms of OCD
Genetic factors: key genes
COMT gene:
Regulated dopamine production
Mutated in some individuals with OCD
SERT gene:
Affects serotonin transport
Changes can lead to decreased serotonin
Evidence for genetic factors
Twin studies:
Higher concordance rates in MZ twins (68%)
Lower concordance rates in DZ twins (31%)
Family studies show increased risk if a relative has OCD
Suggests genetic predisposition, but not sole cause
Neural factors: neurotransmitters
Dopamine:
Higher levels of associated with OCD
Linked to compulsive behaviours
Serotonin:
Lower levels associated with OCD
Connected to anxiety symptoms
The ‘worry circuit’
Involved several brain regions:
Orbitofrontal cortex
Basal ganglia (caudate nucleus)
Thalamus
Over activity in this circuit linked to OCD symptoms
May lead to excessive worry and compulsive behaviours
Evidence for neural factors
Studies show:
Increased activity in orbitofrontal cortex of OCD patients
Correlation between OCD patients
Correlation between OCD symptom severity and brain activity
Shrug studies:
Altering serotonin levels can reduce OCD symptoms
Strengths of Biological explanations
Provides basis for drug treatments - SSRIs
Offers objective, meaureable factors
Helps reduce stigma by showing OCD as a ‘brain disorder’
Supports further research into biological treatments
Limitations and alternative views of biological explanation
Criticised for being biologically deterministic
Doesn’t fully explain environmental influences
Diathesis-stress model:
Combines genetic predisposition with environmental triggers
Over 50% of OCD patients report past traumatic events
