It appears that regular cannabis use [0] decreases dopaminergic brain-activity [1].<p>Dopamine is often referred to as &quot;pleasure&quot;-transmitter, but it&#x27;s function in certain parts of the brain is better thought of as &quot;regulating expectation&quot;, therefore influencing drive &amp; motivation. It makes it possible to work on stuff you don&#x27;t particularly enjoy by focussing on an expected long-term reward. This works by enabling your conscious thoughts to silence other, more excitatory and emotional parts of your brain via a feedback-loop. [2]<p>People with ADHS have trouble concentrating because this feedback-loop doesn&#x27;t work well when they&#x27;re not moving. Sitting still, they are constantly being flooded with inappropriate and negative emotions. They calm down when taking stimulants like Ritaline, because the &quot;calming&quot;-function of the brain starts working properly.<p>Bottom-line: Cannabis has many good effects, but it definitely blunts motivation. [3]<p>[0] rule of thumb: more than once weekly<p>[1] <a href="http:&#x2F;&#x2F;www.pnas.org&#x2F;content&#x2F;111&#x2F;30&#x2F;E3149.abstract" rel="nofollow">http:&#x2F;&#x2F;www.pnas.org&#x2F;content&#x2F;111&#x2F;30&#x2F;E3149.abstract</a><p>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Frontostriatal_circuit" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Frontostriatal_circuit</a><p>[3] <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=WeYsTmIzjkw" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=WeYsTmIzjkw</a>