First, I think your friend is lucky to have you in her life. Your level of caring is inspiring. There are several things that can cause memory loss and you have identified Posttraumatic Stress Disorder (PTSD), Dissociative Identity Disorder (DID), Depression, and dementia. Let’s take a look at each one.
PTSD comes from a chronic mental and emotional stress that happens as a result of a deep psychological shock that most often disturbs sleep, with a constant recollection, usually with vivid detail of the shock or injury that’s taken place. (To learn more about PTSD, please read here.) But there are many variations of what causes a posttraumatic stress disorder, one of which is known as Complex PTSD (C-PTSD).
You will learn in this link that C-PTSD has different criteria than the diagnosis for PTSD, but this differential is subtle and not often fully recognized, even by therapists. Also, C-PTSD is not a formal diagnosis that appears in the Diagnostic Statistical Manual (DSM) which is used by clinicians for identifying a collection of symptoms. It is classically seen as something that has emerged from an assortment of different sources:
- The client experienced prolonged and multiple traumas lasting for a period of months or even years.
- The traumas come from someone who the victim had a deep interpersonal relationship with and was part of his or her primary care network, the most common example being a parent.
- They experienced these traumas as permanent features of life, seeing no end in sight.
- They had no power over the person traumatizing him or her.
I am not suggesting your friend has this, but I am suggesting it may be worth having her make an appointment with a clinical psychologist who is licensed to be able to perform testing that could help you identify your diagnosis more readily. Because C-PTSD isn’t an official category in the DSM individuals who may meet its criteria may have been given the label PTSD because it is the only one officially recognized.
Dissociative Identity Disorder (DID) is something that would also need to be diagnosed by a mental health professional, typically a clinical psychologist or psychiatrist. For an accurate assessment, a direct evaluation in person with a professional is best. You can learn more specifically about DID here.
In the past DID was known as (and is still sometimes referred to as) Multiple Personality Disorder. The disorder is a way the psyche tries to deal with traumatic or abuse and the personalities have emerged to help cope with different aspects of life. Very often these personalities are compensatory for something the individual is unable to do in their life. As an example, an unassertive person might form an aggressive or highly assertive personality to compensate.
A common symptom is for an individual with DID to lose track of time and there may be significant intervals that are lost due to one of the entities takes control. It is typically not commonly diagnosed in the population, and the best methods of treatment often involve psychotherapy aimed at integrating the identities into the core personality.
Most typically there are several symptoms that underly DID and the primary one is that it disrupts the person’s identity as other “personalities” or personality states manifest. These often include different voices, and in some cultures can even be identified during these states as being possessed.
These states disrupt the individual’s identity because there is a gap between one’s sense of self and motivation toward one’s goals with changes in emotional expression, behaviors, memories, feelings, and perceptions. Often these gaps result in memory loss of everyday events, including the specific features of one’s own personality and identity. The role of wife, sister, student, girlfriend, etc., that might make up the individual’s identity are usurped by other, interfering and often competing personalities. These disruptions cause gaps in memory that are beyond what would be considered normal forgetting. These indicators typically cause significant stress in the person’s life because it directly impacts the quality of relationships, and aren’t the result of other medical issues such as seizures.
Depression symptoms can vary from mild to severe and can include:
- Feeling sad or having a depressed mood
- Disengaged, with a loss of interest or pleasure in activities once enjoyed
- Changes in appetite — weight loss or gain unrelated to dieting
- Insomnia or sleeping too much.
- Loss of energy or increased fatigue
- Anxiety-related physical activity (e.g., hand-wringing or pacing) or slowed movements and speech (actions observable by others)
- Loss of meaning or purpose, feeling worthless or guilty
- Difficulty thinking, concentrating or making decisions
- Thoughts of death or suicide
- A clinical psychologist can offer an evaluation that can help make a definitive diagnosis, and a psychiatrist can make a more definitive analysis of the need for medication.
Dementia is caused by many conditions. As you will learn in this article there are a wide variety of symptoms and memory loss is almost always included as a primary one. Some conditions that cause dementia can be reversed, and others cannot. The two most common forms of dementia in older people are Alzheimer’s disease and multi-infarct dementia (sometimes called vascular dementia). These types of dementia are irreversible, which means they cannot be cured, however, symptoms can often be treated.
Rather than guess at what the possibilities are in a diagnosis a very thorough evaluation by a neuropsychologist, clinical psychologist, psychiatrist, or neurologist would be the first place to get your friend to. The stressors you mention she is going through could be the source — or the aggravation of the condition. Only a good clinical evaluation by one of these professionals with experience in making a differential diagnosis would help sort through what is at the root of your friend’s problem and what a good treatment approach should be.