depression has many forms. Lets briefly discuss each one
Great depression: during big depression symptoms are daily or almost daily, intensive, severe. They are so obvious that are noticed at work, school, during having relations with people. symptoms should last at least for 2 weeks in order to diagnose. If you don't take treatment this condition will last 6 months and even more. Some people have only one episode of depression but usually big depression is repeatable illness. In order to make diagnosis it's crucial to exclude the factors that primarily cause depression. For example, this may be hypothyroidism, psychological stress, drug addiction, alcoholism. If this factors are justified big depression won't be diagnosed.
Atypical depression. Despite the name, atypical depression isn't rare. It's common in young generation and women. This form of depression can be characterized with overweight, overdosed appetite and sleepiness, not lack of appetite and insomnia. Feeling of heaviness in hands and feet are typical. Such patients are especially sensitive towards criticism, failure and denial. At the same time their lives are full with conflicts, it's hard for them to keep long-term relations. Fearing denial and failure they even may neglect one or another relationship. From time to time, being with friends or hearing good news, vanishes depression feeling, but as the time passes the symptoms will show up again.
Dysthymia (repeatable, light depression). Dysthymia is a light form of depression, though it's a chronic condition. Symptoms of dysthymia isn't as obvious as in case of Greatd depression , though it lasts for 2 years, often – even more. Due to such length dysthymia violates normal rhythm of life. Due to the light depression that lasts for years people lose interest for everyday activities, self assessment and productivity decline. Other people consider them too critical, they always whine and don't have the feeling of happiness. If you leave dysthymia without treatment, big depression may be added and this condition is called dual depression. When person has dysthymia, he/she has the feeling that was always had depression. Despite this dysthymia may be treated, even after several years of being without diagnosis and treatment.
Seasonal affective disorder. This form if depression is cyclic and seasonal condition, which arises at the same time of the year. Symptoms of depression often show up in autumn and lasts for the whole winter. Very rarely seasonal affective disorder starts in summer and spring.
Autumn-winter depression symptoms are different form spring-summer depression symptoms. If in first case hopeless condition, lack of energy, sleepiness, overdosed appetite and etc.in second case irritation, nervousness, insomnia, weight loss and lack of appetite are common. In general. Mood changes with the weather, but if emotional instability lasts for one or two seasons, this may be seasonal affective disorder, so take a visit to doctor.
Bipolar disorder. This one is also called maniacal-depression disorder. The illness is characterized with alteration of depressive and maniacal episodes. If during depression person is depressed, hopeless, loses sense of happiness and interest of life, during maniacal episode shows up euphoria, surge of energy, overdosed optimism, fast speech, affective and aggressive actions. At this period person's mental ability isn't full valued, concentration – declined. Alteration of depressive and maniacal episodes may be as rare (several times a year), as very frequent (several times a day). Seasonal alteration of episodes is also typical.