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Well as such after looking your serum lithium levels which are within the maintenance range of 0.6-1 meq/l , you do not need to change the dose of lithium, but yes if the levels go further down when you get the levels checked next time, then you shall discuss the possibility of getting your dose revised so as to maintain the levels within the above mentioned range.
Also Seroquel at 25 mg / day dose is quite ideal for maintenance of bipolar symptoms, so this dose shall be continued as well.
Now , the gloomy feel that you developed can be best explained by a) prolonged abstinence from any sort of alcohol form + b) interaction of alcohol with Seroquel both of which are known for depressing CNS ( central nervous system ) actions thereby producing gloomy feeling, sloppiness and sleepiness ,etc
So I reckon that alcohol is best to be avoided in your case since you are on some drugs mainly Seroquel which do not react well with alcohol, even small amounts of it may precipitate such a scenario all over again plus bipolar disorder in itself feeds on making the person to abuse substances with potential of addition and abuse.
So until your doctor keeps you on Seroquel you shall avoid any form of alcoholic beverage , even the mild beer as later once he brings you off Seroquel then you may seek his approval to take alcohol in mildest form occasionally but as of now this gloomy feel that you developed gives us signal that your system does not tolerate even small amounts of alcohol with the current drug regime and so you shall avoid it in order to continue to enjoy the quality of life that you have got with the help of this drug regime.
I hope you see the bigger picture and the benefits which come with sticking to apparently strict but relevant and effective treatment protocol.
Wish you all the best.
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