• Scientific Evidence
• Helpful actions - what can you do?

It is already known that there is a significant amount of overlap between people with mood disorder diagnoses and people who abuse substances. This is especially true of people with bipolar disorder – statistics from the NIMH estimate that 56% of individuals with a bipolar disorder diagnosis also abuse substances. There are also significantly increased rates of alcoholism among adult family members of children who have bipolar disorder (source: The Bipolar Child, p. 166).

It is difficult to determine whether substance abuse has an independent effect on an individual’s risk for developing bipolar disorder, or whether it is a reflection of efforts to self-medicate (alleviate troubling symptoms with alcohol or drugs) by individuals who are already on their way to a bipolar diagnosis. Some authors are now suggesting an independent, causal role for chronic alcohol abuse, in individuals both with and without a familial risk.

Alcoholism might possibly increase mood disorder risk by a few different mechanisms - because it involves similar genetic factors, or because having parents or relations with alcoholism creates an environment for relatives (esp. children) that is highly stressful, and thus a more likely environment to precipitate a mood disorder. As of now, the exact relationship is not clear, and supporting and dissenting evidence exists for each mechanism hypothesis.

Several studies have attempted to tease out the correlations between substance abuse (particularly of alcohol) and mood disorders. Some (Todd and Geller 1996, Wals M 2004) have presented familial data showing that although there is a significant overlap between alcoholism and mood disorders within family groups, the two seem to be transmitted independently – that is, the presence of one diagnosis in a family member does not raise the risk of developing the other diagnosis in currently unaffected family members. This is supported by studies showing that children of alcoholic parents without a family history of affective disorder do not have particularly higher rates of affective disorders themselves (although they do have a host of other adjustment and behavioral problems).

Todd and Geller (1996) studied the family histories of affective disorders and alcoholism in 79 children with Major Depressive Disorder and 31 age-matched healthy controls. During the 2-5 year period of the study, 25 of the depressed subjects developed bipolar disorder. Todd and Geller found that while there was a high degree of co-diagnosis (both an affective disorder and alcoholism) in adult relatives of all the children with affective disorders, the children who eventually developed bipolar disorder had a significantly higher degree of non-affective, paternal alcoholic adult relatives than either the depressed children or the healthy controls. This suggests that the risk for bipolar disorder is somehow related to higher rates of paternal alcoholism in the family, and that the transmission of the two disorders does not always co-aggregate (in other words, this data supports independent transmission). The alcohol dependence of adult relatives is probably not explainable by the stress of having (and possible caring for) an ill family member, as there is no reason to suspect that it is any more or less stressful to have a majorly depressed relative than it is to have a relative with bipolar disorder. The authors suggested that risk factors for developing mood disorders in children included (independently) both affective disorders on either maternal or paternal side, and alcoholism on the paternal side.

What are the possible explanations for this pattern of transmission? One intriguing possibility is that genes contributing to either bipolar disorder or alcoholism have a pleiotropic effect – that is, they influence many different traits in an individual’s biology. Thus, when exposed to other certain factors – either the presence of other critical genes, or environmental factors – the pleiotropic gene in some individuals may have effects that manifest traits of bipolar disorder, and in others, it may only cause substance abuse disorders. If the presence of other genes is necessary to set the course, this may help to explain children in families with high rates of alcoholism but no history of affective disorder are not at higher risk for developing affective disorders themselves. This is not the only explanation – other possibilities include the chance of misdiagnosis (individuals with alcoholism actually had an unrecognized dual-diagnosis).

Another small pilot study (DelBello 1999) suggested that alcoholism might increase the risk of developing mood disorders for people who are not at as much of an increased genetic risk – that is, do not have a loaded family history of affective disorders. In a study of 51 patients hospitalized for a first-time manic episode, authors found that those who had a history of alcohol abuse prior to their hospital admissions had an older age of onset, and significantly fewer family members with affective disorders, than those who did not have a prior history of alcoholism. It is always possible that these subjects were self-medicating symptoms that manifested before their hospitalization; however, non of them had a prior psychiatric history, or had been receiving any antipsychotic, anti-depressant, or mood stabilizer medications. The authors suggested, based on this data, that alcohol abuse may precipitate mania in individuals that would otherwise not be at high risk.

This demonstrates a hypothetical concept known as kindling - use of substances such as cocaine or alcohol kindles (induces) permanent neurological changes in the brain. In these people, the theory goes, the chronic substance abuse kindles the onset of bipolar disorder. Without the substance use, the disorder would not manifest.

We can speculate about the unknown damaging effects that chronic alcohol use may have on the brain, particularly on the developing brain of children and adolescents. One study (De Bellis 2000) showed that adolescents (n = 12) who abused alcohol had a significantly smaller hippocampus size than age-matched controls who did not; other areas of the brain were comparable in size. The authors of that study suggested that the developing hippocampus in adolescents may be particularly susceptible to the damaging effects of alcohol at this age. The hippocampus is an area known to be affected in people with bipolar and other affective disorders. Another study of 23 children exposed to fetal alcohol syndrome before birth reported that they had an increased risk for mood disorders, with bipolar disorder being the most prevalent (O’Connor et al 2002).

Dr. Terence Ketter, Professor of Psychiatry and Chief of the Bipolar Disorders Clinic at Stanford University, believes that substance abuse is one possible path to bipolar disorder for children with first-degree bipolar relatives. Children with a first-degree relative with bipolar disorder often present with symptoms of conduct disorder, disruptive behavioral disorder, or ADHD. Then as puberty hits, depression can set in, and many teens will start experimenting with substances to alleviate their moods. "It's almost like the early onset [of symptoms in children with first-degree bipolar relatives] drives the substance abuse comorbidity. And then in later teens, you start getting some mood cycling," said Ketter during a Q and A session at the 1st Annual Stanford Schizophrenia and Bipolar Education Day (July 30, 2005). "My sense is that, for manic-depressive illness, pre-pubertal disruptive behavioral disorders, post-puberty depression, substance abuse, and then later on mood-cycling, is one potential pathway that can occur. If we could diagnose earlier and intervene appropriately, things could get better."

Whether or not alcohol abuse may cause bipolar disorder, it is known to make the course of the illness more severe. Bipolar patients who also abuse substances tend to have an earlier onset of their disease, more frequent relapses, and a more severe course overall (Brady et al 1995). Winokur et al (1998) suggested that drug/substance abuse may precipitate earlier mania onset for those in families already genetically predisposed to developing the disorder.

Helpful Actions:

Especially if you have bipolar disorder and/or alcoholism in your family, you should make extra efforts to avoid frequent use of alcohol and drugs. It may have a protective effect against the future manifestation of a mood disorder, or reduce the severity of eventual symptoms. Demitri Papolos in "The Bipolar Child" states: "...in the majority of the children [subjects of a study] who had been diagnosed with bipolar disorder before the onset of puberty, the family histories revealed mood disorders and/or alcoholism coming down both the maternal and paternal sides. When the data was analyzed, it showed that over 80% had this unique 'bilineal transmission' " (p. 167).

Parents with children and pre-teens who have a first-degree relative with bipolar disorder should be especially careful. Talk to your teen openly about the increased risks that they may be exposing themselves to if they experiment too much with substances. Help them understand that alcohol is not a tool for rebellion or an effective way to blunt painful emotions, but rather a social privilege (if one chooses to use it) to be handled responsibly and maturely.

The following resources might help to open up conversation on tough topics such as substance abuse and mental illness:

• Drug Abuse and Mental Illness Fast Facts - real facts about the risks to share with your teen (National Drug Intelligence Center)
• Helping you Child Navigate their Teenage Years: A Guide for Parents (White House Council on Youth Violence, Dec 2000). PDF file
• Keeping Youth Alcohol and Drug Free (SAMHSA publication)
• Talking to kids about tough issues (articles and links from the Community Alliance for Youth)
• Parenting is Prevention (SAMSHA website)

Seeing a doctor or a psychiatrist to check out the first possible signs of a developing mood disorder will help you find effective treatment early, reducing the likelihood of resorting to substances later to alleviate symptoms. Checking up on troubling symptoms is not a sign of weakness or hypochondria – it is a sign of responsibility. 

If you are concerned about the symptoms of a developing mood disorder in a loved one, it is important for the doctor or psychiatrist to know the family history of psychiatric disorders and substance abuse. For children, especially, the presence of both affective disorders and alcoholism in adult relatives may point to a diagnosis of bipolar disorder.

If you are pregnant, avoid ALL substances, including alcohol, drugs, over-the-counter medications (including aspirin), caffeine, and herbal supplements. Talk with your doctor about any prescription medications that you take regularly, to determine if they are safe for your baby.

Scientific Studies:

• Multiple dimensions of familial psychopathology affect risk of mood disorder in children of bipolar parents. Am J Med Genet B Neuropsychiatr Genet. 2004 May 15;127(1):35-41
• Psychiatric illness in a clinical sample of children with prenatal alcohol exposure. Am J Drug Alcohol Abuse. 2002 Nov;28(4):743-54
• Familial rates of affective and substance use disorders in patients with first-episode mania. J Affect Disord. 1999 Nov;56(1):55-60
• Alcoholism and drug abuse in three groups--bipolar I, unipolars and their acquaintances. J Affect Disord. 1998 Sep;50(2-3):81-9
• Increased prevalence of alcoholism in relatives of depressed and bipolar children. J Am Acad Child Adolesc Psychiatry. 1996 Jun;35(6):716-24
• The relationship between substance abuse and bipolar disorder. J Clin Psychiatry. 1995;56 Suppl 3:19-24. Review