What is manic-depressive illness due to? What is the problem in the brain cells?

No brakes. Bipolar disorder, the new and approved term for manic depressive illness can be thought of as an emotional roller coaster without the brakes. The problem isn't so much with the nerve cells themselves but the coordination of the chemical modulators that control their expression.

Related Questions

Can someone who has a manic depressive illness such as bipolar disorder apply for disability benefits?

Depends. On the severity of the illness, most patients with bipolar disorders function well without needing disability benefits.
Disability. Sure can, depending on chronicity and effect on psychosocial functioning, although no guarantee it will be approved. Get help from your doctor with the application.
Apply - yes. However, success of the application will depend on diagnosis, impairment and quality of documentation.

Manic-depressive illness... How close are scientists to finding a cure for it?

Getting closer. At last we have semantic agreement on what constitutes bipolar disorder--what it is and is not. The neurohormonal elements are now better elucidated; but not yet to the point where cure is a reasonable expectation. More likely there are several diverse conditions which mimic each other but work through different mechanisms; hence requiring different "cures".
We are not there. Yet. I am grateful that treatment for bipolar disorder has improved so much since I was a resident. There is hope for managing the disorder and improving quality of life but I don't know of any actual "cures" on the horizon. Take care.
Likely not. Manic depression, more precisely known today as bipolar disorder quite likely will not be curable anytime soon. However, it can be managed effectively with therapy and mood stabilizing medications such as lithium and depakote.

How sedatiing is the effect of the medication for bipolar disorder (manic-depressive illness)?

Bipolar. Depends on the medication. Some psychotropics are sedating, such as seroquel (quetiapine) or risperdal.
Many. Mood stabilizers are sedating but could be given at night to help with sedation. Sometimes the sedative effect helps for manic patients who have insomnia.
Variable. Some of the medications used as mood stabilizers (eg seroquel) can be quite sedating which may be of benefit for mania when someone may have a decreased need for sleep. Other mood stabilizers are usually not sedating (eg Abilify (aripiprazole) and lamictal). Others may be sedating for some individuals and not for others (eg lithium, depakote, trileptal, tegretol, or topomax).
Totally depends onw. Which medications are used. Meds fall into classes of mood stabilizers (Lithium​/ anticonvulsants like valproic acid, divalproex or lamotrigine) & atypical antipsychotics (Quetiapine, aripiprazole, olanzapine or risperidone).

If you have bipolar manic depressive illness do you see a psychiatrist or a psychologist?

Bipolar. A therapist can see patient initially, then refer to psychiatrist for medication evaluation, or a psychiatrist trained in psychotherapy can do both. I tend to do both & refer to marital counselors & group therapists.
Bipolar. Studies have shown that without meds, approximately 70 % of bipolar patients cannot be functional in personal, social or work life. Most patients need 2 or 3 meds over their life time. Psychiatric stabilizations with meds is the key first and then a combination of psych meds, therapy, group therapy can help, in serious cases ECT can help.
A combination is. Often a good choice. Recommend ensuring that you have a psychiatrist involved in your care for management of psychotropic medications.
Eval. Get a full psychiatric evaluation for bipolar disorder. If bipolar disorder is found, then medications, typically mood stabilizers will be prescribed. Therapy is also strongly indicated. If The evaluation is negative for bipolar disorder, medication still may be needed. In that case therapy is also strongly indicated.

What is the reputation about manic depressive illness aka bipolar? Are patients supposed to be wildly impulsive?

It all depends. Not likely. However, the truth is behavioural control of an individual.
Impulsivity. Without consistent treatment with mood stabilizers, then yes, a person with bipolar disorder can get sick & become impulsive. When manic, they can spend money without thinking, get involved in wild business schemes, stay up all night, talk rapidly, and change subjects suddenly. On the depressive end they can impulsively kill themselves. Treatment helps prevents these devastating outcomes.
It Depends. Bipolar disorder is characterized by erratic moods that can involve impulsivity during manic episodes, but can be reduced and possibly avoided with ongoing medical treatment by an experienced psychiatrist. For many patients who suffer from bipolar disorder, there can be periods of normalcy that generally are not associated with impulsivity (unless it is part of a different diagnosis).
Agree with Dr Pappas. Impulsivity is a common component of mania and may be represented by excessive spending, sexual indiscretion, or other risky behaviors, but not necessarily "wildly" impulsive.

Is manic-depressive = bipolar disorder?

Yes. Manic-depression is a descriptive term for bipolar disorder.
Manic depressive. Is old term for bipolar disorder, which can include bipolar type 1, type 2, manic type, depressed type, with psychosis, without psychosis, or nos (not otherwise specified).
Bipolar Disorder. Its an other way of describing the mood fluctuation that does happen with mood disorders. Its the change in moods from lowest depression to extreme mania or high extreme moods.
Interchangable. The terms are interchangable. Bipolar I and bipolar II, In the first, manic phases are more severe, and in the second, depressive phases are more severe. There is also cyclothymia which is a low grade version of bipolar disorder in general, where mood swings are not as severe in either direction, manic or depressive. No one knows how it develops, other than a mystery of genetic confluence.

Manic depressive disorder vs major depression, what is the difference?

These are different. Diagnosis. People with depression may have bouts with depression followed by periods when they are less depressed. They do not have manic episodes. Bipolar disorder is a physical illness like diabetes that does not go away, it simply can be controlled using and adjusting the proper medication throughout your life. Having a good psychotherapist and psychiatrist is imperative. I hope this helps.
Diagnosis. Major depressive disorder is characterized by depressive symptoms that negatively effect quality of life. Manic depressive disorder is a historical term for what is now bipolar effective disorder. This may include episodes of depression but is characterized by episodes of mania To stay consistent some refer to major depressive disorder as unipolar depression.
Bipolar. Manic depression, known clinically as Bipolar I and bipolar II, In the first, manic phases are more severe, and in the second, depressive phases are more severe. There is also cyclothymia which is a low grade version of bipolar disorder in general, where mood swings are not as severe in either direction, manic or depressive. Major depressive disorder is only major depression, without any mania.