I would say that you have memory problem or deficit attention from what you describe.It could be also small or moderate epilepsy;people that are epileptic sometime they are not there mentally.I know someone that have that he falled down when he was a child and that is what he as epilepsy he loose connection and awareness of what is happening for some short laps of time fee second or fee minutes. Since you have add a car crash i would say to go see the doctor. From what you describe your body run on automatic since you do not remember getting somewhere and also it is not the right place and you do not notice that you are not at the right place. explain that to your doctor ask for a check up he can do a brain scan and some test for memory and awareness. for epilepsy they have some medication to take daily to stop those seizure from happening.

So the depression might not be the right diagnostic,since your mind can have some trauma from your car crash that happenned when you where younger.

It is important that you counsult a doctor because if you have seizure often you can have accident or cause accident.

look at this link:

http://en.wikipedia.org/wiki/Epileptic_seizure

normal doses of certain drugs that lower the seizure threshold, such as tricyclic antidepressants

Did you take antidepressants?

It can cause seizure,here is the list of tricyclic antidepressants,you can look if you are taking one of those medication. The TCAs include the following agents which are predominantly serotonin and/or norepinephrine reuptake inhibitors:

Amitriptyline (Tryptomer, Elavil) Amitriptylinoxide (Amioxid, Ambivalon, Equilibrin) Butriptyline (Evadyne) Clomipramine (Anafranil) Demexiptiline (Deparon, Tinoran) Desipramine (Norpramin, Pertofrane) Dibenzepin (Noveril, Victoril) Dimetacrine (Istonil, Istonyl, Miroistonil) Dosulepin/Dothiepin (Prothiaden) Doxepin (Adapin, Sinequan) Imipramine (Tofranil, Janimine, Praminil) Imipraminoxide (Imiprex, Elepsin) Lofepramine (Lomont, Gamanil) Melitracen (Deanxit, Dixeran, Melixeran, Trausabun) Metapramine (Timaxel) Nitroxazepine (Sintamil) Nortriptyline (Pamelor, Aventyl, Norpress) Noxiptiline (Agedal, Elronon, Nogedal) Pipofezine (Azafen/Azaphen) Propizepine (Depressin, Vagran) Protriptyline (Vivactil) Quinupramine (Kevopril, Kinupril, Adeprim, Quinuprine) and

Amineptine (Survector, Maneon, Directim) - Norepinephrine-dopamine reuptake inhibitor Iprindole (Prondol, Galatur, Tetran) - 5-HT2 receptor antagonist Opipramol (Insidon, Pramolan, Ensidon, Oprimol) - σ receptor agonist Tianeptine (Stablon, Coaxil, Tatinol) - Selective serotonin reuptake enhancer Trimipramine (Surmontil) - 5-HT2 receptor antagonist

http://en.wikipedia.org/wiki/Tricyclic_antidepressant

Go see the doctor tell him you have seizure memory lost and and lost of awareness or counscience. And that you add a car accident when young and add allready memory lost at the hospital after the car accident.And that you might have epilepsy or brain trama similar to epilepsy,causing you seizure.

The International League Against Epilepsy (ILAE) define an epileptic seizure as "a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain."[5] Epileptic seizures can occur in someone who does not have epilepsy – as a consequence of head injury, drug overdose, toxins, eclampsia or febrile convulsions, for example.

Medically, when used on its own, the term seizure implies an epileptic seizure. The lay use of this word can also include sudden attacks of illness, loss of control, spasm or stroke.[5] Where the physician is uncertain as to the diagnosis, the medical term paroxysmal event and the lay terms spells, funny turns or attacks may be used.

I might not be a doctor but i find it logical that if you add car accident and memory lost as a child.

And have been diagnose as depressive when having a seizure,and that antidrepessent medication can cause you more seizure, that the doctor that have diagnose you as depressif might not have give the proper diagnostic,was it a lack of knowledge from is part? Did you tell him the car accident and the memory lost as a child?Did you tell him what you experience when you have those seizure?Did he check for brain trauma(brain scan,memory test,awareness test,put you in observation to see what is happening with you)?

Did you ever run into people that seem to know you well but you feel you never meant them?

They seem to act like, "What is wrong with you?" Maybe even they call you by a different name than you ever heard.

Do you ever wonder where you got new cloths or shoes but have no memory of buying anything?

Did you have an abusive childhood?

These aren't questions so much you have to answer to me as much as consider if you have.

If you have, please see a psychologist that knows DID or MPD.