What is depression?
Depression is a simple word but it has deep and vast meaning, In my words Depression is a feeling generated by your state of mind, it is a sad feeling, or feeling low, not feeling good, not feeling energetic are usually used to express depression and person say I am depressed. Depression is very common problem nowadays. It is a real medical illness which comes in many forms and really needs attention.
Though it is a feeling in your mind state but it may be a real illness or disease. So you have to know what depression is. Life is full of ups and down and sometimes person may not accept all aspects of life and can feels sad or goes in to depression, which not only affect the person who is depressed but also his surroundings or family members who are very close to the person.
Usually people think, feeling sad or feeling dull is depression, but it is more than that, there are few signs and symptoms which can help you to diagnose depression.
1. Persistent sad feeling or anxious, loneliness, emptiness.
2. Loss of interest in daily activity and hobbies. Person may lose the interest in daily activities and he or she may lose the interest in his or her favorite activity or hobby also. He may lose interest in sex too.
3. Sleep disturbance – problem in falling asleep or problem in waking up or disturbed sleep.(Either sleeping too much or less)
4. Fatigue, low energy – person will always feel tired (fatigue), or dull. No motivation to work. Ability to think and speak are slowed down which may affect body movements too.
5. Guilt or feeling of hopelessness or worthlessness.
6. Poor concentration – person cannot concentrate on work, affects ability to take decisions, impacts memory, person finds hard to remember or recall things.
7. Suicidal thought or harming himself by any mean
8. Change in appetite- Though decrease in appetite is common but in some people there may be increase in appetite. So weight loss and weight gain both can be seen.
9. Other psychological disturbances like irritation, agitation, mood changes may be seen.
10. Unexplained body aches may also be seen like headache, pain in abdomen or in any body part.
For diagnosis at least five of these symptoms should be present during most of days, almost every day for at least two weeks and severely interrupting daily activities. If you have these symptoms then make a doctor appointment and talk to doctor in detail.

It is not necessary that all these signs will be present in a depressed person but only few of them may also present so counselling and asking questions related to all these symptoms are very important for diagnosing the problem. And if you are asking questions you have to take the patient under your confidence and make sure that information provided by the patient will not go outside. The most important question asking about suicidal thoughts or any thought to harm him-self or her-self.

Causes-
There may be different causes of depression from genetic, biochemical, environmental to any life event. Depression can occur in any age but more often starts by the age 16. In teenagers stress may be related to school life, studies or friends, any trauma, love relations, loss of loved one or any other. In adults causes may be related to family life, stressful situation between partners, work load in the office, competition everywhere, infidelity, not getting success at work, unsatisfactory jobs, any trauma or loss of loved one and much more. Sometimes depression is medication induced, related to medical problems and long term illness. In women depression may be due to hormonal changes during menstrual cycle, before menstruation known as pre menstruation syndrome (PMS). After delivery of baby depression is called as postpartum blues which is more common in women due to hormonal and physiological changes in body and adding another responsibility in her life of taking care of baby.

Depending on symptoms, duration and cause depression may be of different varieties-
Major Depression- Symptoms are severe enough to interrupt daily activities, and presents at least two weeks with noticeable change in previous level of functioning.
Bipolar I Disorder-Mood disorder in which patient experiences manic symptoms (elated mood) for at least one week that cause significant distress or impairment in his/her level of functioning.
Dysthymic Disorder-It is a chronic disorder characterized by depressed mood that presents most of the time during the day and present on most days for at least two years.
Cyclothymic Disorder- A chronic disorder characterized by many episodes of depressed mood and in between many episodes of hypomanic mood (Mild elated mood) for at least two years.
Seasonal Affective Disorder-It is characterized by depressive symptoms usually in winter months and in snowy places,when there is absence of sunlight, people can not go outside, all the activities are limited inside the closed home.
Post traumatic depression- After any trauma or because of loss of loved one .It is different from Grief in which usually return of normal baseline functioning within two months but in depression patient do not returns to his baseline level functioning.
Postpartum Depression- Symptoms starts within one month after giving birth to baby and may continue for long time.

Diagnosis-
Usually symptoms and physical exam can diagnose the Depression ,no lab tests are necessary but sometimes to rule out medical causes doctor may order for lab tests.