Phelps-Nourse  addiction test was prepared and introduced by two M. D. s Janice Keller Phelps and Alan E Nourse who had written extensively on addiction and it is based on the authors theory where biochemical factors have a role to play in addiction. The test has five parts that includes diet, family history, depression, alcohol and drug use.
The diet part of the questioner focuses on sugar and starchy foods and the authors believe that sugar is addictive in whatever form it is used. Because of that the food items mentioned in the test are foods that have a lot of sugar in them such as sugar in its plain form, honey, syrup, jams, jellies and some of the pastries that are full of sugar, etc. and the questions ask how often individuals are using them on a range varying from one day to a month.
The other question is how often individuals crave for the mentioned sugary food items and it continues to probe how eating such food items affect the individuals, obviously to see if there is an obese behavior such as overeating. The question in the first part is focused on sugar and how much of it individuals use in a given day and if their sugar consumption habit had made it difficult for them to control their weight, simply because the amount of sugar intake is one of the known causes of obesity.
Then it goes into various sickness symptoms among which are those that could get a boost from eating sugary or starchy foods such as low energy and fatigue, being motivated, concentration, and a depressed state of mind that could lead into being discouraged or disoriented because of not knowing exactly what to look for. Overall, this section tries to find out the effect of eating sugary and starchy food could have on the performance of the individuals answering the questionnaire and how dependent they are on it.
The second section focuses on family history and starting from their consumption habit of sugary and starchy food items, to their drinking habit, their caffeine intake in a given day, if any relative had a weight control problem, if there had been recovering alcoholics among the family members, or if there were some who were consuming more than a certain amount of liqueur, if they were using narcotics, use of over-the-counter tranquilizers, their smoking habit, were they using sleeping pills or recreational drugs, and if they were hyperactive while they were children and the test in the second section has a sore between 0-5.
The third section has 10 questions that are directly related to being depressed such as lack of sleep at night, mood changes that could involve crying often, pushing oneself to do things, sexual malfunction, psychological problems that cause fear and anxiety, lack of interest, attempting suicide and summarizing questions if these factors had affected the normal living condition of the individuals.
Here it gets interesting because the questions start asking individuals if they had to use all those known mind altering drugs to alleviate the above mentioned problems. Then it goes on asking if individuals had been dealing with any of the problems such as depression for a prolonged period or if they had been hospitalized for substance abuse, and drugs such as Elavil, Imipramine, Ludiomil etc, individuals often use to relieve or get rid of such psychological and mood problems are mentioned.
The fourth section strictly focuses on the effect and use of alcohol starting from the amount consumed, how often it is consumed, reason for consuming it, its effect such as throwing up or passing out, its psychological interference in the day-to-day life of the individuals consuming it, if there had been regrets and guilty feelings, if there had been craves and the environment and circumstances the drinking occurs or takes place.
The main focus in this section is to see the exact effect of alcohol consumption and to know how much individuals are dependant on drinking as well as if it had led them into trouble such as driving while under the influence of the substance. This section seems to be more exhaustive in such a way that it tries to find out the exact cause of drinking alcohol and its effect. The fifth and the final section deals with drugs of all sorts and the first on the list are sleeping pills and the list includes tranquilizers, diet pills, and painkillers.
Then the other interesting question is if individuals take any kind of pill to feel better on a daily basis. The serious drugs such as opium, morphine, heroin, cocaine, and all the other recreational drugs are also included and individuals have to tell if they were using them or if they had received medical or institutional treatment for using them. Smoking is also in the list, it includes how often chewing tobacco and cigars are used. There are also caffeine producing drinks and how often the individuals use them, mainly to know the quantity of the caffeine intake.
At the end of the test there is a score and it states that if the score is lower the risk factor for the individuals to become addicted with any of the mentioned substances is low, and what the low score is below 50. A score between 50-100 would mean there is the likelihood of becoming addicted with any of the mentioned substances in the test, even if the finding does not distinguish which particular substances to avoid, but individuals are advised to be on guard, without being too descriptive.
The authors who are responsible for the test are known to be believers that sugar itself could be addictive in such a way that those who get certain advantages from consuming it such as energy or more focus in doing things could be dependant on it to such an extent that without it their performance level could suffer, which is proven to be true in life, although sugar for some reason is not labeled as an addictive substance anywhere else, and the body needs it naturally as it needs other substances revealing that it is not a drug.
Nevertheless, if the score is more than 100 the individuals are vulnerable to become addicted with any of the addictive substances they come in contact with. The score for each section should also be taken into consideration because a score of more than 12 for the depression section could be a signal that the individuals could become addicted with any of the drugs they are using to make their situation better.
Or according to the result individuals who do not know about their family history but who could score below 50 because they consume a small quantity of sugar and do not drink nor use drugs could become addicted to any of the substances because of heavy influence of family history, although it is difficult how science will treat such a finding, but it is possible to say that the genetic factor of being vulnerable for addiction has scientific backup.
Another possibility where a low score could be deceiving is when those taking the test are using drug and alcohol regularly to mask their depression, and they take a small amount of sugar since they consume alcohol. In a situation like this, it is possible to get a low score and still have an existing addiction problem.  Before going into some of the scientific findings about substance addiction there are other factors that are not mentioned in the test that have a decisive effect on individuals becoming addicted to substances.
Obviously personality is one of them where not only depression, but psychological disorders such as attention-deficit, post traumatic stress disorder, and when it comes to young people those who exhibit aggression, or lack of self-control and have a difficult temperament could be more vulnerable to become substance abusers. The social environment also plays a vital role where young people could always be under peer pressure to abuse substance that could make it difficult for them to refuse.
The lack of parental guidance and intervention and being lonely in decision making could also make young people victims for substance abuse.  The genetic factor might also have some influence in individuals becoming addicts but what could be more influential is if there is such a problem in the immediate family where the young people are brought up in and that could lead to addiction more than the general family history, an issue that is not addressed in the test.
The type of drugs involved also could make a difference where some of them such as heroine and cocaine could be highly addictive and the habit-forming process could take place in a short period. The availability of drugs, how much they cost, all have a compounding effect in becoming addicts, because individuals tend to use drugs that they have access to easily, without costing them a lot of money.  Consequently, addiction could be defined as a chronic, relapsing brain disease that results in having an urge to use or abuse the use any of the various classified addictive substances for a prolonged period.
Addiction is also proven to be a brain disease more than anything else because it can change the brain’s structure by interfering on how it functions normally and could lead into a behavioral change unless it is treated at an early stage. The test does not address what makes individuals abuse substances where some can do it for pleasure because most drugs create some level of euphoria when they are used and the popularity and use of a particular drug depends directly to what it offers in a form of euphoria.
The other victims are those who have some kind of psychological complication such as social anxiety, stress, depression, lack of confidence, hypertension, fear, and the like that would choose to use substances because they could enable them overcome such problems temporarily by making them feel better or enabling them to attain a high level of confidence. Another area that had been victimizing individuals is better performance, whether it is in athletics, cognitive ability, or other physically demanding activities where a high level of energy and interaction is required.
In such situations since some drugs improve performance for as long as they are in the system of the individuals who are using them, the addiction follows when the need to keep that performance level permanently, and when the only way to achieve that is by using particular substances, which would easily lead into addiction and the questionnaire has not dealt with such issues that should affect its being an effective measuring tool.
There are some that could be trapped into substance abuse out of curiosity or due to peer pressure or just by meeting the wrong kind of individuals, assuming that individuals who have various substances exposure could be a danger to themselves and others, and such circumstances could avail the first encounter that could lead to addiction. The proven problem with drugs is those who start using them for the most part could be convinced that they can have them under control, but the most likelihood is the substances could take over making individuals heavily dependant on them.
When that happens there are other problems that will follow at the same time depending on the individuals and their health, as well as their private and public life such as work that could suffer. In case of young people, they will find it difficult to continue their education and the need to support their habits could lead them into criminal activities among others. This could happen to adults too unless they get treatment quickly. 
A voluntarily taken drug initially could easily take control of the victim and when that happens the mental health of individuals had already been affected because brain imaging of individuals had shown that there is a physical change on the brain of individuals who abuse various drugs and areas in the brain that are responsible for critical judgement, decision-making, learning and memory, and behavior control will be affected, in fact will be physically changed.
What had been touched on in the test could have some truth even if the risk factor of individuals tend to differ due to certain experiences is not given consideration, yet if an individual could easily be affected by past family history simply because the individual could have an inherent weakness that is out of the individual’s control makes things more complicated and what this shows is there is a possibility that there are certain genes that are vulnerable for addiction.
If that is so, it might not even require having a family history of addiction to have a risk factor, a gray area that needs clarifying. Some say children that are born from parents with substance abusing problem could be more vulnerable because they could inherit the risk factor from their parents through their gene that could have led a normal life otherwise if the parents were not exposed to substance such as alcohol, especially mothers while they are pregnant.
In addition, saying that if a distance family member had been substance abuser the same thing could happen to any of the family members might need more explanation, because what it would mean is there are certain genes that are vulnerable to addiction in spite of someone else had been abusing substance or not and such individuals will have to do more to stay away from any kind of substance abuse, yet since those genes are not identified it will make things more difficult, but it would serve as a signal more than anything else if a family member had the problem it could mean the risk factor is there.
Biological makeup, should also include gene, gender, ethnicity, and should also be used hand-in-hand with upbringing and the environment one grows up in, live, and work instead of trying to reach at a conclusion by gene only.  Other factors that might worsen the addiction problem could be early start that could develop into heavy using as the age progresses. The early start could be compounded with other factors such as the genetic vulnerability as it was used in the test, where anyone who has a family history of mental illness has the risk factor of depression and similar psychological problems that were mentioned in the test too.
Family problems such as marriage breakup at the early years of children, and abuse that could be both physical and mental, economic problem in some cases all could add up to the complication of becoming an addict and should have been part of the test. The way the drug is administered might also have an effect, because it is the duration of the high what counts and if it expires quickly there will be the urge of using the drug repeatedly to stay at the same high level, why many beginners would become abusers.
If accepting addiction as a complex illness is possible, knowing exactly how it affects the brain could show why it is so although it will be difficult to put that in the test. There is a scientific proof that a given part of the brain has a specific function such as the cerebellum is responsible for coordination and memory is processed by the hippocampus. Neurotransmission is the process through which the nerve cells or neutrons are communicating message with each other.
This means information passes through electrical impulses among the many neurons in the brain. What is key in the brain function that has a direct relation with addiction is what is known as the reward pathway that has three parts the ventral tegmental area, the nucleus accumbens, and the prefrontal cortex. Accordingly, when activated by rewarding stimulants such as food, alcohol, and sex it is transmitted by the neurons from the ventral tegmental area to the nucleus accumbens and then up to the prefrontal cortex.
Any stimulant consumed reaches to the brain through blood and reaches all part of the brain but its euphoric effect is felt by the area around the reward pathway. What is interesting here is neurotransmission is processed through a number of chemical substances that are known as neurotransimitters and one such substance is called dopamine that will be released by a neuron and reaches the other neighboring neurons with the signal. The dopamine then will have to make it back to the original neuron through a specialized protein dopamine transporter.
Any of the stimulating substances have the capability of interfering with this process resulting in a big dose of the dopamine to be accumulated without reaching back its original destination, which is believed to be the source of the euphoria. Sugar also could have a similar effect on the brain even if the euphoria felt from sugar intake is nonexistent when compared to some of the recreational drugs such as alcohol and cocaine, and because of that, it is not addictive, but it is something the body needs to function, including the brain which uses glucose to function normally. 6] This could bring us to a conclusion that there is a scientific back up concerning genes even if still the particular genes that are vulnerable are not clearly specified and the other influences such as upbringing, the social environment where young people live and grow, the peer pressure, and other psychological complications such as depression, loneliness, being hyperactive could force people more to go into abusing substances.
At the same time the focus on sugary and starchy food in the test might also be misleading because the body needs carbohydrate naturally to function normally because that is going to be the source of its energy, but how much is taken could be monitored, whereas none of the other substances that are abused are essential for the body.
What this means is the body cannot function normally without enough energy and naturally the foods people eat either have sugar or carbohydrate in them where both are basically sugar in different forms, and labeling them as addicting substances could again be misleading, simply because the body, unless it is made to develop the habit it can function normally without any of the other addictive substances and some of the psychological problems they are believed to help improve have different kinds of treatments.
The result of the test might not be that reliable since its two major sections are not very much effective in measuring someone’s vulnerability to drug use, because a family member that had encountered a different living environment, or peer pressure, or bad company could develop dependency on addictive substances, while another member of a family that has a proper upbringing, family support, good education growing up in a good environment where there is no economical problem, and where access to drug is very limited could avoid being trapped in any of the substance addictions.
Other than that since sugar and starchy foods had been used in most of the sections that could be a particular finding the authors could be convinced about but there is no scientific backup for it, which would make it misleading.