Irving's doctor prescribed valium to him cope with job-related anxiety. he found a less stressful job, and is anxiety-free. however, irving keeps taking valium because he likes its effects. he hasn't had to increase the dosage, and he did not have withdrawal symptoms when he forgot to take his pills. it is most likely that irving is

He is psychologically addicted to Valium, but not physically.

Explanation:

Compared to the physical dependence, this type of dependence is associated with one's behaviors and emotions when it comes to the certain dependence on something. It shows us the mental state of an individual that's going through the withdrawal, that's on the beginning of developing the dependence or simply recovering from it.

It is as serious as physical one, but people tend to think that is is a lighter form of addiction.

It's followed by symptoms that are associated with this kind of dependence:

anxiety, appetite loss, issues with cognitive functions like judgment loss and concentration and memory, issues with sleeping and a feeling of not being able to stop consuming a certain thing are only some of the common symptoms when someone is dealing with psychological dependence.

the gravitational force on an object increase as the mass of an object also, im not going to report you, but this question should be under the science category, not health