phenotypic variations of corticotropin releasing hormone (CRH) and arginine vasopressin (AVP), and down-regulation of adrenal functioning) as well as forebrain serotonergic mechanisms. Since this model is highly provisional, further research is still needed. Diagnosis
The Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV), published by the American Psychiatric Association, characterizes dysthymic disorder. The essential symptom involves the individual feeling depressed for the majority of days, and parts of the day, for at least two years. Low energy, disturbances in sleep or in appetite, and low self-esteem typically contribute to the clinical picture as well. Those with the condition have often experienced dysthymia for many years before it is diagnosed. People around them often describe them in words similar to "just a moody person". The following are the diagnostic criteria:
During a majority of days for two years or more, the adult patient reports depressed mood, or appears depressed to others for most of the day. When depressed, the patient has two or more of:
decreased or increased appetite;
decreased or increased sleep (insomnia or hypersomnia);
fatigue or low energy;
reduced self-esteem;
decreased concentration or problems making decisions;
feelings of hopelessness or pessimism. During this two-year period, the above symptoms are never absent longer than two consecutive months. During the duration of the two-year period, the patient may have had a perpetual major depressive episode. The patient has not had any manic, hypomanic, or mixed episodes. The patient has never fulfilled criteria for cyclothymic disorder. The depression does not exist only as part of a chronic psychosis (such as schizophrenia or delusional disorder).
Irritability is one of the more common symptoms in children and adolescents.Mild degrees of dysthymia may result in people withdrawing from stress and avoiding opportunities for failure. In more severe cases of dysthymia, people may withdraw from daily activities. They will usually find little pleasure in usual activities and pastimes. Diagnosis of dysthymia can be difficult because of the subtle nature of the symptoms and patients can often hide them in social situations, making it challenging for others to detect symptoms. Additionally, dysthymia often occurs at the same time as other psychological disorders, which adds a level of complexity in determining the presence of dysthymia, particularly because there is often an overlap in the symptoms of disorders.There is a high incidence of comorbid illness in those with dysthymia. Suicidal behavior is also a particular problem with those with dysthymia. It is vital to look for signs of major depression, panic disorder, generalised anxiety disorder, alcohol and substance use disorders, and personality disorder. Causes
There are no known biological causes that apply consistently to all cases of dysthymia, which suggests diverse origin of the disorder. However, there are some indications that there is a genetic predisposition to dysthymia: "The rate of depression in the families of people with dysthymia is as high as fifty percent for the early-onset form of the disorder".