The psychological effects of cannabis take place almost immediately after smoking it (2-10 minutes) with the highest peak between 30-60 minutes. After 2-4 hours the effects have mostly disappeared. After eating cannabis it takes about 1-2 hours before the effects show up, and they can last 3-10 hours. The most important effect of cannabis is an intensification of the emotional situation you are in, but can vary a lot from person to person. It depends on the quantity of cannabis taken, the personal condition (like your mood at the moment you use, and your accessibility to the effects of cannabis), the way to use cannabis (smoke or eat), and the experience of the user.
Despite the big individual differences there are also psychological effects that are typical for the use of cannabis. After using it, you get high or stoned. An euphoric feeling comes up and slowly changes into a satisfying feeling of calmness and relaxation. You get dopey and the feeling of time slows down so that it seems like minutes last for hours. Colors, shapes and smells become more intense and are seen differently. Other typical reactions are the desire to eat, especially sweet things (food kick) and an uncontrollable fit of laughter (laugh kick). Real hallucinations, i.e. seeing and hearing things that don't exist, never or hardly ever occur after using cannabis. There can also be negative effects. The changing perception can cause feelings of anxiety, panic and confusion, and people who don't feel well before they use can experience a deterioration and worsening of the negative mood.