Symmetry symptoms in obsessive-compulsive disorder: clinical and genetic correlates

Abstract

Objective: In obsessive-compulsive disorder (OCD), symmetry-related symptoms may be important. Although clinical correlates of symmetry-related symptoms have been identified in OCD, few data exist on genetic associations. Animal studies indicate involvement of dopamine in symmetry-related behavior, suggesting this may be relevant to analogous symptoms in OCD. Alterations in dopamine may also reflect environmental influences. However, the association of symmetry-related symptomatology, early adversity, and polymorphisms in dopaminergic genes has not been investigated in OCD. Methods: Clinical information and polymorphisms in key dopaminergic genes were compared between OCD patients with primary symmetry symptoms and those without. Results: OCD patients with primary symmetry symptoms comprised 46.6% (n=210) of the sample (n=451), and were older (p o 0.01), had longer illness duration (p o 0.01), higher OCD severity scores (p = 0.01), and greater comorbidity (p o 0.01) than those without. In Caucasians (n=343), genotype frequency differed significantly between groups for ANKK1 rs1800497, with more OCD patients with symmetry symptoms being homozygous for the A2 (CC) genotype (w 2 = 7.296; p = 0.026). Conclusion: Symmetry symptoms have some distinct clinical features and may represent a marker of severity in OCD. However, clinical associations, in combination with the association found with the ANKK1 rs1800497 A2 variant, suggest that primary symmetry symptoms may represent a distinctive clinical and psychobiological profile.

Obsessive-compulsive disorder: Insights from animal models

“…Heterogeneous distribution within a population of animals (see Fig. 5) (Korff et al, 2008) suggests a genetic association akin to OCD (Lochner et al, 2015). While the prevalence of OCD is markedly lower than that of high stereotypic (H) animals in a deer mouse population (45%, Fig.…”

Does neuropsychological performance in OCD relate to different symptoms? A meta-analysis comparing the symmetry and obsessing dimensions

“…The mixed clinical presentation and treatment outcomes across symptom domains may suggest different underlying mechanisms (Rasmussen et al., ). Indeed, genetic investigations have demonstrated unique associations with variants of particular neurotransmitter receptor and transporter genes (Lochner et al., ; Viswanath et al., ). Neuroimaging studies offer evidence suggesting S/O and O/C dimensions may relate also to different structural and functional patterns.…”

Symmetry Dimension in Obsessive–Compulsive Disorder: Prevalence, Severity and Clinical Correlates

“…Functional neuroimaging studies suggest that OCD dimensions may be mediated by partially distinct subjacent neurocircuits [ 18 , 19 ], and that among them, the symmetry dimension may have unique genetic [ 20 , 21 ] and neural [ 18 , 19 ], correlates. In neuropsychological studies, higher scores in the symmetry dimension were associated with poorer verbal fluency, which involves set shifting capacity and cognitive flexibility [ 22 , 23 , 24 ].…”

“…Regarding demographic and clinical correlates, the symmetry dimension has been associated with male sex [ 4 , 17 , 25 , 26 , 27 , 28 , 29 ], early onset of obsessive–compulsive symptoms [ 8 , 27 , 28 , 30 , 31 , 32 , 33 , 34 , 35 ], longer duration of symptoms [ 21 , 27 , 36 ], and presence of tics or tic disorders [ 37 , 38 ]. Additionally, associations with family history of OCD [ 8 , 39 , 40 , 41 , 42 ], greater OCD severity and functional impairment [ 16 , 21 , 26 , 32 ], and suicidal behaviors [ 43 , 44 ] have been reported.…”

“…In other words, symmetry compulsions are usually aimed at reducing feelings of discomfort, manifested as an unpleasant subjective experience that something is not right, and performing their behaviors (e.g., arranging behaviors) until things look just right [ 50 , 51 , 52 , 53 ]. Regarding psychiatric comorbidities, the symmetry dimension has been associated with tic disorders [ 37 , 38 ], attention deficit and hyperactivity disorder (ADHD) [ 41 ], panic disorder and agoraphobia [ 21 , 30 ] posttraumatic stress disorder (PTSD) [ 21 ], obsessive–compulsive personality disorder [ 8 , 21 , 54 ], substance use disorders [ 30 , 41 ], bulimia nervosa [ 15 ], and bipolar disorder [ 30 ].…”