Attention Deficit Hyperactivity Disorder Causes, Signs, Symptoms & Effects

Often times the signs of ADHD can be difficult to identify. One of the most important steps in the recovery journey is understanding the signs, symptoms and side effects of ADHD.

Understanding ADHD

Learn about ADHD

Attention-deficit/hyperactivity disorder (ADHD) is a mental health disorder that is defined as a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with daily functioning. Some of the problems caused by adult ADHD include unstable interpersonal relationships, low self-esteem, poor scholastic or work performances. While ADHD can cause many problems for individuals, it is a treatable disorder that can be managed with a combination of medication and therapies. While once considered to be a disorder limited to childhood, we now know that the symptoms of ADHD often exist well into adulthood.

Each feature of this neurobehavioral disorder has a variety of different symptoms and may be expressed differently by each individual. Inattention is defined as wandering off task, lacking persistence, having difficulty sustaining focus, and being disorganized. Hyperactivity is excessive motor activity when it is not appropriate, excessive fidgeting, or extreme talkativeness. Finally, impulsivity are the hasty actions that occur in the moment without any previous thought where the actions can be potentially harmful to him or herself or others. Impulsivity can stem from the inability of a person to delay gratification or can be displayed as making important decisions without thinking through the long term consequences.

In order to receive the diagnosis of ADHD, the disorder must have begun in childhood with the majority of the symptoms occurring before 12 years of age. Expressions of these symptoms have to be present in more than one setting, with symptoms typically varying depending upon the context within a given setting. However, symptoms may be absent when an individual is receiving rewards for good behavior or is engaged in especially interesting activities. Although ADHD always starts in childhood it is possible that this disorder may not be properly diagnosed until later in life.

ADHD may first be noticeable when a child is a toddler, but it can be hard to distinguish excessive motor activity from highly normative behavior of a child before the age of 4. It is most often recognized in elementary school when the inattention becomes more prominent and begins to cause impairment in scholastic functioning. ADHD is relatively stable throughout early adolescence and through the teenage years. In most individuals the symptoms of motor hyperactivity become less obvious, however problems with restlessness, inattention, poor planning, and impulsivity seem to remain. There is a significant portion of children with ADHD who continue to present with symptoms far into adulthood.

Treatment for ADHD is similar in both adults and children and generally involves a combination of stimulant therapy, other medications, therapy, and treatment of mental and health conditions that may co-occur with ADHD.


ADHD statistics

It is estimated that ADHD occurs in the general population in approximately 2.5% of adults. In the general population, ADHD occurs more frequently in males than in females with a male-to-female ratio of about 1.6:1. Females however are more likely than males to present with inattentive features of the disorder.

Causes and Risk Factors

Causes and risk factors for ADHD

While researchers have found a number of factors that can lead to the development of ADHD, there is not one specific cause given for the development of the disorder. It is generally believed that ADHD is a combination of a number of factors working together to cause the condition. These include:

Genetic: ADHD has been found to run in families and it has been indicated that genetics may play a role in the development of ADHD. Having a first degree relative, such as a parent or sibling with ADHD increases the risk for developing the disorder.

BiologicalResearch has shown that certain areas of the brain may be a cause of ADHD. Certain areas of the brain such the frontal lobe, basal ganglia, caudate nucleus, and cerebellum are all involved in regulating behavior and any problems with the structure or function of these areas of the brain may lead to an individual developing ADHDIt’s been theorized that problems affecting the central nervous system may lead to the development of ADHD. If you were born prematurely before 37 weeks gestation, you may develop ADHD.

Environmental: There is a potential for increase in the risk for developing ADHD if you’ve been exposed prenatally to polychlorinated biphenyls (PCBs) during your gestation. If your mother smoked, drank, or abused substances during her pregnancy you may have a higher chance for developing ADHD. Lead paint, commonly found in older buildings, exposure as a child may increase the risks for developing ADHD.

Psychological: It’s very common for people who have ADHD to have mental health disorders, such as autism spectrum disorders, substance addiction, personality disorders, tic disorders, or intermittent explosive disorder.

Signs and Symptoms

Signs and symptoms of ADHD

There are a variety of signs and symptoms that can occur in individuals with ADHD which can make detection and diagnosis of the disorder a challenge for many. The severity and frequency of symptoms displayed depend on the type of ADHD the individual has. Some of the symptoms include:

Inattentive symptoms:

  • Fails to pay close attention to details or makes careless mistakes
  • Difficulty sustaining attention
  • Restlessness
  • Mood swings
  • Doesn’t seem to listen when directly spoken to
  • Does not follow through on instructions
  • Fails to complete school work or work place tasks
  • Difficulty organizing tasks and activities
  • Difficulty completing tasks or assignments
  • Often avoids or dislikes tasks that involve sustained mental effort
  • Frequently loses things
  • Easily distracted by irrelevant stimuli
  • Forgetful in daily activities

Hyperactive-impulsive symptoms:

  • Fidgets or taps hands or feet
  • Trouble handling stresses
  • Extreme temper
  • Leaves seat in situations when seating is required
  • Runs about or climbs things in inappropriate settings
  • Unable to engage in activities quietly
  • Often talks excessively
  • Often interrupts or intrudes on others
  • Blurts out answers before question is finished
  • Difficulty to wait ones turn


Effects of ADHD

If the symptoms of ADHD are not properly managed they can cause a variety of problems in an individual’s life. Some effects include:

  • Social rejection and isolation
  • Substance abuse
  • Incarceration
  • Family relationship problems
  • Poor occupational performance
  • Academic problems
  • Elevated interpersonal conflict
  • More traffic accidents and violations
  • Family and relationship problems
  • Physical and mental health problems

Co-Occurring Disorders

ADHD and co-occurring disorders

It is common for adults with ADHD to present with co-occurring disorders. The most common co-occurring disorders are:

  • Intermittent explosive disorder
  • Substance abuse disorder
  • Personality disorders (especially antisocial personality disorder)
  • Obsessive-compulsive disorder
  • Tic disorders
  • Autism spectrum disorder