What double dip? House prices in the United States are reaching new levels of volatility, defying trendy labeling. Tuesday news from Standard & Poor's/Case-Shiller index found the average price of a single-family home reached a new low in the first quarter and is now at 2002 levels. However, mortgage data tracker and industry service provider CoreLogic found Wednesday the average national price for a home increased a marginal 0.7% from March to April. It is the first increase since the expiration of the homebuyer tax credit in mid-2010, CoreLogic notes. Last month, the home price index from CoreLogic posted a decline of nearly 6%. The CoreLogic year-over-year number, however, resembles the negative findings of the S&P index. National home prices, including distressed sales, declined by 7.5% in April 2011 compared to April 2010. Excluding distressed sales, year-over-year prices declined by 0.5% in April 2011 compared to April 2010. “While the economic recovery is still fragile and one data point is not a trend, the month-over-month increase based on April sales activity is a positive sign. This is the first month-over-month increase in the HPI since government support for home buying was removed, and it provides reason for cautious optimism,” said Mark Fleming, chief economist for CoreLogic. Even more notable is the top states that saw home price appreciation are outstripped by the massive declines seen in the top five declining markets. Overall, the five areas with the highest appreciation were: North Dakota (+4.2%), Vermont (+3.4%), New York (+3.2%), Washington D.C. (+2.2%) and Mississippi (+1.4%). The five states with the greatest depreciation were: Idaho (-15.2%), Michigan (-13.2%), Arizona (-11.9%), Rhode Island (-11.6%) and Nevada (-11.4%). Write to Jacob Gaffney. Follow him on Twitter @JacobGaffney.