Can hypomania be induced by just thinking quickly and variably? Emily Pronin and Daniel Wegner have shown that fast and variable thinking induces positive affect. This is independent of thought content. Sheri Johnson has noted that the key things that might start a hypomanic/manic episide are a night of no sleep, a positive life experience, and certain drugs.

Is it possible to clinically induce hypomania by just thinking quickly and variably?

Note that an easy exercise to implement this would be to think of a word and then a word beginning with the previous word's letter.

Added. In a sense, the above exercise is "anti-meditation." Mindfulness is essentially low thought speed combined with high variability. The ideal state would be high thought speed and high variability. 

References


Pronin, E., &amp; Wegner, D. M. (2006). Manic Thinking Independent Effects of Thought Speed and Thought Content on Mood. Psychological Science, 17(9), 807-813.
I had a read through the Pronin and Wegner study. 
The study had a sample size of 144. They manipulated thought speed by getting participants to read aloud one statement after another at either half normal reading speed (slow thinking) or double normal reading speed (fast thinking). They also manipulated the content of the text being read (depressing statements versus elated statements). They seemed to find that both the content and the speed of thought manipulation seemed to yield similar increases in positive emotion, energy, feelings of power, feelings of creativity, and grandiosity.

The first issue is whether their study is replicable. I don't know the literature regarding replications, but all the effects seem plausible, and the sample size is reasonable for this kind of study. 

Another issue is how the manipulation of reading speed affected the reported emotions. Perhaps the slow reading led to frustration or being annoyed. 

With regards to the nature of the effect, there are questions of how long this mood induction lasts. My guess is that the effect of the mood induction would be short lived.

There is also a difference wherein mania the speed of thought is presumably internally driven whereas on this task the "speed of thought" is externally driven. The study did not measure whether this "speed of thought" continued after the external stimuli was removed. For example, does speed of thought work with an inertial principle or not such that it can be started with external stimuli and will keep going on its own. My guess would be even if such a concept of inertia existed, people would quickly return to their own typical level. Thus, I don't think such a manipulation would induce clinical levels of mania, especially not in a sample of participants who do not suffer from bipolar disorder.