I believe your physician is on the right track with lamotrigine. Depakene (valproic acid) and lamotrigine interact with each other regardless of how long you have been on one or the other. Some individuals can develop a life threatening rash when initially starting lamotrigine, this is the reason why your doctor started you on a very low dose.

However, many individuals can tolerate rapid dosing of lamotrigine, but the increased risk this presents is something that needs to be acknowledged and discussed beforehand. Thankfully if you do develop a rash with rapid dosing, you can rechallenge the drug at a lower titration later: PMC1201641

You also asked if you truly had this illness, based on your age and the response you had to paroxetine, wait and see how you respond to lamotrigine and other diagnostic tests.

I went for ten years with the diagnoses of Bipolar Disorder II, until one day my wife and I became frustrated with our inability to have children. It turns out I had a, benign, pituitary tumor the whole time that was causing hyperprolactinaemia and secondary hypogonadism. The point I'm trying to make is you need a full neurological and neuroendocrine workup for a proper diagnoses. It is best to think of psychiatric illnesses as knowledge gap disorders, so you have to rule out things we can test empirically first.

Nuclear imaging studies are nice to have if you can afford them, but even most classical neurological disorders do not exhibit structural problems with the brain. I think the most bang for your buck would be to start with a neuroendocrine workup by a board certified endocrinologist. It may just be my personal experience, but these are the only individuals with the scientific mindset required to root out a complex problem. Psychiatry is entirely too content in calling it good with a half assed explanation and a fist full of pills.

But to answer your question, yes you're probably suffering from some form of bipolar disorder. It doesn't answer the underlying cause, but a young adult presenting with manic switching on antidepressants, corticosteroids, or even something like pseudoephedrine, is indicative of someone who can benefit from medications traditionally used in the treatment of bipolar disorder. A great resource for you to begin with is psycheducation.org.

You have written half a sentence about your girlfriend and relationship troubles, so I can't offer any assistance with this; why do you say your illness is influencing your relationship?

You haven't indicated that you're a harm to yourself or others, why would your therapist insist that you be hospitalized? Hospitalization is incredibly disruptive to a patient's life, in addition to being psychologically damaging to their sense of well-being. The last thing you want is to be straddled with thousands of dollars in costly hospital bills. Civil commitment is strictly for individuals who are a harm to themselves or others. A once in a lifetime dream vacation would be a fraction of the cost of a hospital stay, and probably also result in a better outcome too! That money can be put to better use elsewhere, enough said.

This could in-fact all be "happening to you", you're mom may be right that you need to stop everything. The trouble is you still haven't explored why you became depressed in the first place. Simply put, why did you feel the need start taking paroxetine? Why did you think that would help you? What empirical findings have made your doctors believe you have a neuropsychiatric illness? Did all your labs come back normal?

It's not hopeless, stick with the lamotrigine for now. It's a great choice for treatment resistant depression, regardless of whatever underlying disease you may have. It's not a matter of relying or not relying on medications. Lithium is to Iron, as bipolar disorder is to Iron deficiency anemia. Some people "need" to have more to function correctly. In fact, if lamotrigine helps, taking low dose Lithium carbonate (say for instance 0.4 mEq/L) as a prophylaxis may actually be all you need to function well for the rest of your life.

"The mania episode was horrible enough, I didn't expect a huge depression to come afterwards." I'm guessing you experienced a dysphoric or mixed mania, as few individuals rarely complain about euphoric mania. Your respond is typical of individuals that are susceptible to drug induced psychotic states. I would urge you to educate yourself about what compounds you can put in your body, this alone could adequately explain your situation. Some individuals are just more "delicate". I can't take pseudoephedrine, prednisone, amphetamines, and nearly the whole class of serotonin altering compounds, as they'll make me bat ***** crazy real quick. I can't even take over the counter Benadaryl for more then a week without it seriously altering my physiological state.

Also, depression is often a rational response to living in this crazy world. Pick up a hobby to keep your mind off the insanity surrounding you. Let me know if you have any more questions.