The dopamine and norepinephrine pathways that originate in the ventral tegmental area and locus coeruleus project to diverse regions of the brain and govern a variety of cognitive processes. The dopamine pathways and norepinephrine pathways which project to the prefrontal cortex and striatum are directly responsible for modulating executive function (cognitive control of behavior), motivation, reward perception, and motor function; these pathways are known to play a central role in the pathophysiology of ADHD. Larger models of ADHD with additional pathways have been proposed. Brain structure
In children with ADHD, there is a general reduction of volume in certain brain structures, with a proportionally greater decrease in the volume in the left-sided prefrontal cortex. The posterior parietal cortex also shows thinning in individuals with ADHD compared to controls. Other brain structures in the prefrontal-striatal-cerebellar and prefrontal-striatal-thalamic circuits have also been found to differ between people with and without ADHD.The subcortical volumes of the accumbens, amygdala, caudate, hippocampus, and putamen appears smaller in individuals with ADHD compared with controls. Structural MRI studies have also revealed differences in white matter, with marked differences in inter-hemispheric asymmetry between ADHD and typically developing youths Functional MRI fMRI studies have revealed a number of differences between ADHD and control brains. Independent component analysis performed on resting-state fMRI data have revealed that individuals with the inattentive type of ADHD have significantly more independent components are required to describe the variance of this data.
Goes to excessive lengths to obtain nurturance and support from others, to the point of volunteering to do things that are unpleasant. Feels uncomfortable or helpless when alone because of exaggerated fears of being unable to care for themselves. Urgently seeks another relationship as a source of care and support when a close relationship ends. Is unrealistically preoccupied with fears of being left to take care of themselves.The diagnosis of personality disorders in the fourth edition Diagnostic and Statistical Manual of Mental Disorders, including dependent personality disorder, was found to be problematic due to reasons such as excessive diagnostic comorbidity, inadequate coverage, arbitrary boundaries with normal psychological functioning, and heterogeneity among individuals within the same categorial diagnosis. World Health Organization
The World Health Organizations ICD-10 lists dependent personality disorder as F60.7 Dependent personality disorder:
It is characterized by at least 4 of the following:
Encouraging or allowing others to make most of ones important life decisions;
Subordination of ones own needs to those of others on whom one is dependent, and undue compliance with their wishes;
Unwillingness to make even reasonable demands on the people one depends on;
Feeling uncomfortable or helpless when alone, because of exaggerated fears of inability to care for oneself;
Preoccupation with fears of being abandoned by a person with whom one has a close relationship, and of being left to care for oneself;
Limited capacity to make everyday decisions without an excessive amount of advice and reassurance from others.Associated features may include perceiving oneself as helpless, incompetent, and lacking stamina.