Table 2.

Summary of findings on immunological comorbidity in Tourette syndrome, obsessive-compulsive disorder and attention deficit hyperactivity disorder.

Comorbidity	Tourette syndrome	Obsessive-compulsive disorder	Attention deficit hyperactivity disorder
Autoimmune diseases (% refer to the increase in risk of diagnosis of the specific autoimmune disease)	Hashimoto's thyroiditis (106%)* Celiac disease (67%)* Scarlet fever (62%)* T1DM (37%)* Psoriasis (33%)*	Sjögren's syndrome (94%)* Celiac disease (76%)* Guillain-Barré syndrome (71%)* Crohn's disease (66%)* Hashimoto's thyroiditis (59%)* T1DM (56%)* Scarlet fever (52%)* Idiopathic thrombocytopenic purpura (51%)* Ulcerative colitis (41%)* Multiple sclerosis (41%)* Psoriasis (32%)* Encephalitis or meningitis (591%)# Rheumatoid arthritis (342%)# Rheumatic fever (334%)# Scarlet fever (149%)#	Ankylosing spondylitis (178%)* Autoimmune thyroid disease (153%)* Ulcerative colitis (131%; evidence of stronger association in females)* Crohn's disease (44% in females only; negative association in males)* Psoriasis (57% in females, 31% in males)*
Allergies (% refer to the increase in risk of diagnosis of the specific allergic illness)	Conjunctivitis (33%)* Rhinitis (118%)* Asthma (82%-161%)*# Atopic dermatitis (61%)*	Higher frequency of eczema#	Rhinitis (52%)¶ Asthma (34–80%)¶ Eczema (32%)¶

^*Population-based studies.

^#Clinic-based studies.

^¶Meta-analysis of studies with different design.