Validity and reliability of chronic tic disorder and obsessive-compulsive disorder diagnoses in the Swedish National Patient Register.

OBJECTIVES: The usefulness of cases diagnosed in administrative registers for research purposes is dependent on diagnostic validity. This study aimed to investigate the validity and inter-rater reliability of recorded diagnoses of tic disorders and obsessive-compulsive disorder (OCD) in the Swedish National Patient Register (NPR). DESIGN: Chart review of randomly selected register cases and controls. METHOD: 100 tic disorder cases and 100 OCD cases were randomly selected from the NPR based on codes from the International Classification of Diseases (ICD) 8th, 9th and 10th editions, together with 50 epilepsy and 50 depression control cases. The obtained psychiatric records were blindly assessed by 2 senior psychiatrists according to the criteria of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) and ICD-10. PRIMARY OUTCOME MEASUREMENT: Positive predictive value (PPV; cases diagnosed correctly divided by the sum of true positives and false positives). RESULTS: Between 1969 and 2009, the NPR included 7286 tic disorder and 24,757 OCD cases. The vast majority (91.3% of tic cases and 80.1% of OCD cases) are coded with the most recent ICD version (ICD-10). For tic disorders, the PPV was high across all ICD versions (PPV=89% in ICD-8, 86% in ICD-9 and 97% in ICD-10). For OCD, only ICD-10 codes had high validity (PPV=91-96%). None of the epilepsy or depression control cases were wrongly diagnosed as having tic disorders or OCD, respectively. Inter-rater reliability was outstanding for both tic disorders (κ=1) and OCD (κ=0.98). CONCLUSIONS: The validity and reliability of ICD codes for tic disorders and OCD in the Swedish NPR is generally high. We propose simple algorithms to further increase the confidence in the validity of these codes for epidemiological research.

Familial Risks of Tourette Syndrome and Chronic Tic Disorders. A Population-Based Cohort Study.

IMPORTANCE: Tic disorders, including Tourette syndrome (TS) and chronic tic disorders (CTDs), are assumed to be strongly familial and heritable. Although gene-searching efforts are well under way, precise estimates of familial risk and heritability are lacking. Previous controlled family studies were small and typically conducted within specialist clinics, resulting in potential ascertainment biases. They were also underpowered to disentangle genetic from environmental factors that contribute to the observed familiality. Twin studies have been either very small or based on parent-reported tics in population-based (nonclinical) twin samples. OBJECTIVE: To provide unbiased estimates of familial risk and heritability of tic disorders at the population level. DESIGN, SETTING, AND PARTICIPANTS: In this population cohort, multigenerational family study, we used a validated algorithm to identify 4826 individuals diagnosed as having TS or CTDs (76.2% male) in the Swedish National Patient Register from January 1, 1969, through December 31, 2009. MAIN OUTCOMES AND MEASURES: We studied risks for TS or CTDs in all biological relatives of probands compared with relatives of unaffected individuals (matched on a 1:10 ratio) from the general population. Structural equation modeling was used to estimate the heritability of tic disorders. RESULTS: The risk for tic disorders among relatives of probands with tic disorders increased proportionally to the degree of genetic relatedness. The risks for first-degree relatives (odds ratio [OR], 18.69; 95% CI, 14.53-24.05) were significantly higher than for second-degree relatives (OR, 4.58; 95% CI, 3.22-6.52) and third-degree relatives (OR, 3.07; 95% CI, 2.08-4.51). First-degree relatives at similar genetic distances (eg, parents, siblings, and offspring) had similar risks for tic disorders despite different degrees of shared environment. The risks for full siblings (50% genetic similarity; OR, 17.68; 95% CI, 12.90-24.23) were significantly higher than those for maternal half siblings (25% genetic similarity; OR, 4.41; 95% CI, 2.24-8.67) despite similar environmental exposures. The heritability of tic disorders was estimated to be 0.77 (95% CI, 0.70-0.85). There were no differences in familial risk or heritability between male and female patients. CONCLUSIONS AND RELEVANCE: Tic disorders, including TS and CTDs, cluster in families primarily because of genetic factors and appear to be among the most heritable neuropsychiatric conditions.

Hoarding symptoms and prediction of poor response to limbic system surgery for treatment-refractory obsessive-compulsive disorder.

UNLABELLED: OBJECT.: Recent findings have suggested a correlation between obsessive-compulsive disorder (OCD) symptom dimensions and clinical outcome after limbic system surgery for treatment-refractory patients. Based on previous evidence that the hoarding dimension is associated with worse outcome in conventional treatments, and may have a neural substrate distinct from OCD, the authors examined a large sample of patients undergoing limbic surgery (40 with capsulotomy, 37 with cingulotomy) and investigated if symptom dimensions, in particular hoarding, could influence treatment outcome. METHODS: Data from 77 patients from 3 different research centers at São Paulo (n = 17), Boston (n = 37), and Stockholm (n = 23) were analyzed. Dimensional Yale-Brown Obsessive Compulsive Scale (Y-BOCS; São Paulo) or Y-BOCS Symptom Checklist scores (Boston and Stockholm) were used to code the presence of 4 well-established symptom dimensions: forbidden thoughts, contamination/cleaning, symmetry/order, and hoarding. Reductions in YBOCS scores determined clinical outcome. RESULTS: Mean Y-BOCS scores decreased 34.2% after surgery (95% CI 27.2%-41.3%), with a mean follow-up of 68.1 months. Patients with hoarding symptoms had a worse response to treatment (mean Y-BOCS decrease of 22.7% ± 25.9% vs 41.6% ± 32.2%, respectively; p = 0.006), with no significant effect of surgical modality (capsulotomy vs cingulotomy). Patients with forbidden thoughts apparently also had a worse response to treatment, but this effect was dependent upon the co-occurrence of the hoarding dimension. Only the negative influence of the hoarding dimension remained when an ANOVA model was performed, which also controlled for preoperative symptom severity. CONCLUSIONS: The presence of hoarding symptoms prior to surgery was associated with worse clinical outcome after the interventions. Patients with OCD under consideration for ablative surgery should be carefully screened for hoarding symptoms or comorbid hoarding disorder. For these patients, the potentially reduced benefits of surgery need to be carefully considered against potential risks.

Predictors of medium and long-term outcome following capsulotomy for obsessive-compulsive disorder: one site may not fit all.

Patients with treatment-refractory obsessive-compulsive disorder (OCD) are sometimes considered for surgical interventions. The identification of reliable predictors of outcome following such interventions would be of great clinical importance, as it would lead to stricter selection of suitable patients, thus avoiding unnecessary surgery and improving the overall response rate. We analyzed data from 24 severe treatment-resistant patients who underwent capsulotomy for OCD and were carefully followed-up one year after the surgery and at long term (mean 10.8 years after surgery). The Yale-Brown Obsessive Compulsive Scale Symptom Checklist was administered to assess the lifetime presence of the most common symptom types. We applied an algorithm to calculate the patients' scores on 4 well-established symptom dimensions: Contamination/cleaning, forbidden thoughts, symmetry/order and hoarding. Multiple regression models were employed to examine whether scores on certain symptom dimensions were predictive of long-term outcome. The presence and number of lifetime symptoms in the symmetry/order domain were associated with greater severity of OCD, depression and anxiety, as well as greater impairment in various functional domains like work, social and family life at both one-year and long-term follow-ups. These results remained consistently significant after controlling for preoperative psychopathology, scores on other OCD symptom dimensions, sex, age, age of onset, duration of follow-up, type of surgical procedure, number of operations and lesion volume. The results could have implications for existing ablative and deep brain stimulation protocols and challenge our current conceptualization of OCD as a unitary diagnostic entity with a single neurobiological substrate.