³⁵(Poerio et al., 2015). Intriguingly, the effect of wandering thoughts on mood may depend on whether you think about the past or the future. Ruby et al. (2013) found that future-oriented thinking has a general positive effect on mood, even if the contents were negative; perhaps this is so because when we solve a planning problem, we get happier. In contrast, thinking about past events was found to lead to negative mood independently of the contents of the thoughts. However, Poerio et al. (2013) argue against such results, and in particular point out that future-oriented thinking may increase anxiety based on worrying about what might happen in the future; see also Stawarczyk et al. (2013).