Comorbidity and/or psychopathology in Tourette syndrome: the suggested relationships (modified and updated from Robertson 2003; 2011)
| Comorbidity and/or psychopathology | How common in GTS? | Aetiology | Comments | References | |
|---|---|---|---|---|---|
| 1 | Attention deficit hyperactivity disorder | Very common | Not genetic | Also common in clinic, community and epidemiological studies | Robertson30 |
| 2 | Obsessive compulsive behaviours/symptoms/disorder | Very common | Integral part of GTS; genetically linked | OCB/OCS=egosyntonic; OCD=egodystonic | Robertson31 |
| 3 | Autistic spectrum disorders | 6–11% | Unsure—probably non- specific and as poor general neurodevelopment | Recent studies suggest similar genetics in some cases | Robertson4 |
| 4 | Depression | 13–76% | Multi-factorial; not genetic | Controlled studies=GTS>depressed | Robertson32 |
| 5 | Anxiety | Common | Secondary to having GTS | Robertson28 | |
| 6 | Impulsivity and rage (not ADHD criteria) | Common | Unknown; more research required | Budman et al126 | |
| 7 | Self-injurious behaviours | 30% | Difficult clinical problem to treat | Related to OCB/D; related to impulsivity | Robertson et al127 Mathews et al128 |
| 8 | Personality disorders | Common | Probably related to childhood ADHD, ODD, CD | Whole spectrum of PDs: not restricted to OCPD | Robertson et al129 |
| 9 | Conduct disorder; oppositional defiant disorder | Referral bias | Robertson28 | ||
| 10 | Schizophrenia | Rare | Unrelated; chance association | Robertson28 | |
| 11 | Bipolar affective disorder | Uncommon | Probably related to OCD and ADHD not GTS per se | Robertson28 | |
| 12 | Dysphoria | Common | Adverse side effects of anti-GTS medications | May require adding antidepressant discontinuation of Rx | Robertson28 |
| 13 | School phobia/separation; anxiety | Common | Adverse side effects of anti-GTS medications | May require discontinuation and treatment in own right | Robertson28 |
| 14 | ‘Cognitive dulling’ | Fairly common | Adverse side effects of anti-GTS medications | Patients receiving neuroleptics=lower IQ | Robertson et al130 |
| 15 | Dementia | Nil | No association | n/a | |
| Total comorbidity and/or psychopathology | 88–90% of all GTS patients | Mixed | Clinical and epidemiological | Freeman et al29 Khalifa and von Knorring8 9 |
ADHD, attention deficit hyperactivity disorder; CD, conduct disorder; GTS, Gilles de laTourette syndrome; na, not applicable; OCPD, obsessive compulsive personality disorder; ODD, oppositional defiant disorder; PDs, personality disorders; Rx, treatment.