I'm bipolar 1 and I have always been the most depressed during summers and usually manic around winter and spring.. shouldn't it be the opposite? I know a lot of people become manic in the summer and naturally depressed in the winter which makes a lot more sense than the other way around.. 

spring mania is something else though.. had to get admitted in late March this year. Always seems like mania starts off so good and then it eventually just spirals down into racing negative thoughts.