Climate change happening in the middle and upper atmosphere has been intensively investigating nowadays. One of the experimental tools to investigate long-term changes in the mesopause region between 80 and 90 km altitude is a natural atmospheric phenomenon called noctilucent clouds (NLCs). Being composed of tiny ice particles, NLCs are supposed to be highly sensitive to small changes in the temperature and amount of water vapor at the polar summer mesopause. Many factors such as solar activity, long-term changes in the temperature, amount of water vapor, minor atmospheric constituents, have been considered contributing to long-term NLC changes. At the same time, a role of volcanic activity in the NLC variability has been investigated in a qualitative sense in previous studies so far, and its influence has been found to be inconclusive. For the first time, we quantitatively investigate a factor of volcanic activity in NLC variability for the past five decades. Our analysis reveals that there is statistically significant positive influence of volcanic activity on changes in NLC activity, with a time lag of 7 years between these processes which might be explained by a slow meridional-vertical updraft of ejected volcanic water vapor from the tropical troposphere to the polar mesopause region. We confirm our previous results on no statistically significant long-term trend in NLC activity at middle and subpolar latitudes for the past five decades.