Comparison of Functional Magnetic Resonance Imaging Findings between Attention Deficit Hyperactivity Disorder (ADHD) - Combined Type , Attention Deficit Hyperactivity Disorder - Inattentive Type, Conduct Disorder, Obsessive Compulsive Disorder, and Healthy Controls.

Project no. 22567 · Status: Kapanmış (Yayın bekleniyor) · 2021

Summary

Background and aim: Broad use of neuroimaging methods in the investigation of the aetiology of psychiatric disorders has led to a considerable increase in our knowledge about these diseases. Functional magnetic resonance imaging (fMRI) studies of attention-deficit/ hyperactivity disorder (ADHD) have shown a decrease in activation in the frontostriatal, frontoparietal and frontocerebellar pathways and a compensatory increase in activation in the occipital region, especially during tasks that assess executive functions related to cognitive, emotional, and sensorimotor processes. While some researchers argue that Conduct Disorder (CD) has a common neurobiological origin with ADHD, there are also studies focusing on the aetiology of CD as a distinct entity. Studies are needed to explain how the neurobiological and neuroanatomical nature of executive functions differ in individuals with ADHD and CD, which are frequently seen together. Obsessive-compulsive disorder (OCD) has a heterogeneous clinical phenotype, as in many psychiatric disorders, and different neurobiological pathways and brain regions may play a role in its etiology. Especially activation differences on frontostriatal structures have been revealed in task-based functional magnetic resonance imaging (fMRI) studies that measure motor inhibition and cognitive flexibility in OCD, and different results have been obtained due to the heterogeneous nature of the disorder.Materials and Methods: Right-handed male subjects (n=102) aged 7-14 years without active psychiatric drug use were included in the study. For diagnosis, the cases were evaluated with the semi-structured interview method using The Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version DSM-5. The cases were classified according to the diagnosis as ADHD-Combined Type (ADHD-CT) group (n=30), ADHD-Inattentive Type (ADHD-IT) group (n=24), ADHD comorbid CD (ADHD-CD) group (n = 18) and OCD group (n=12). Healthy controls (n=18) who had a similar age distribution with the other groups and did not have any active medical or psychiatric disease were included in the study. Turgay ADHD Form was given to the parents of the participants, and Turgay ADHD and Teacher Information Form to their teachers. Children’s Yale-Brown Obsessive Compulsive Scale was used to determine the OCD severity level, and the cases diagnosed with OCD who scored 16 points or higher as a result of the scale were included in the study. Functional brain imaging of the patients who accepted to participate in the study was performed with a 3 Tesla MRI. The Go/No-Go task design was used to evaluate the response inhibition of the subjects during the scan.Results: Case groups were compared in terms of Go>baseline contrast and significant activation differences were detected in the right dorsolateral prefrontal cortex (F=9.97, p<0.001; HC>ADHD-CT,ADHD-IT; ADHD-IT>ADHD-CD - F=9,21, p<0,001; HC>ADHD-CD), right anterior prefrontal cortex (F=9.80, p<0.001; HC>ADHD-CD; ADHD-IT>ADHD CD, ADHD-CT>ADHD-CD), right dorsal anterior cingulate gyrus (F=7.69, p<0.001; ADHD-CT>ADHD-CD), and left anterior prefrontal cortex (F=7,05, p<0,001; ADHD-IT>ADHD-CD). Differences were examined in terms of No-Go>baseline contrast and significant activation differences were found in the regions of the right dorsolateral prefrontal cortex (F=7,82, p<0,001; HC>ADHD-CT,ADHD-CD) and right anterior prefrontal cortex (F=7,51, p<0,001; ADHD-IT>ADHD-CD; ADHD-CT>ADHD-CD; HC>ADHD-CD). In No-Go>Go contrast, significant activation differences were detected in the secondary visual field-middle occipital gyrus (k=44, F=9,11, p<0,001; ADHD-CD>ADHD-CT; ADHD-CD>ADHD-IT - k=54, F=7,10, p<0,001; HC,ADHD-CT>ADHD-IT; ADHD-CD>ADHD-IT). When OCD group and healthy controls compared in terms of Go>baseline contrast, a statistically significant hyperactivation was detected in healthy controls regarding the left anterior prefrontal cortex (Cluster Size (k)=844, T=4.46) and left dorsolateral prefrontal cortex (k=844, T=4.20),Conclusion: The results obtained in the present study show that ADHD presentations and ADHD-CD cases differ from healthy controls in terms of prefrontal and cingulate regions involved in attention, response inhibition and executive functions, and occipital regions, which are visual areas related to attention. It is thought that the findings obtained in this study, in which homogenized case groups and different presentations of ADHD were evaluated, were affected by the heterogeneous nature of psychiatric disorders and hereditary differences. It has been found that there are many functional abnormalities in the frontal, temporal, and occipital areas, as well as some subcortical structures, in which executive functions such as focus and response inhibition and attention-related processes are involved in OCD patients. Differences in neurobiological origin can help mental health professionals in explaining different symptom profiles of this disorders.

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