Catalyzes the NAD(P)(+)-dependent oxidation of succinate semialdehyde to succinate, which may enter the citric acid cycle. Is involved in the catabolism of 4-methylaminobutanoate produced from nicotine. Acts preferentially with NADP(+) as cosubstrate but can also use NAD(+). To a lesser extent, is active also towards butyraldehyde (8.5% of the activity observed with succinate semialdehyde) and propionaldehyde (1.6% of the activity observed with succinate semialdehyde) as substrates. H2O + NAD(+) + succinate semialdehyde = 2 H(+) + NADH + succinate H2O + NADP(+) + succinate semialdehyde = 2 H(+) + NADPH + succinate kcat is 23000 sec(-1) with NADP(+) as cosubstrate. Alkaloid degradation; nicotine degradation. Homodimer. Is transcribed only in the presence of nicotine. Belongs to the aldehyde dehydrogenase family.