Modern society, with its emphasis on material possessions and indifference to community, is making us mentally ill. It's an argument that wouldn't seem out of place on the Sunday talk shows, but in this case, it's appearing in the academic journal Clinical Psychology Review, and the argument is backed by decades of data and a cognitive model that attempts to make sense of the process. The data suggests that there has been an increase in a standard measure of mental problems among individuals in their late teens and early 20s, and that the trend dates back at least to the 1930s.
The authors mention that a variety of studies have found mixed results when examining the time course of mental health within the US. Some of the studies that have attempted to address this problem have attempted to extrapolate trends using surveys of people in different age groups, but these studies suffer from two problems: mental health doesn't remain static during an individual's lifetime, and those with serious mental disabilities (such as clinical depression) tend to die younger than their peers.
The alternative approach, however, suffers from its own complications. Although there are a number of standardized tests for measuring mental health, many of these are recent developments, and others have been extensively modified in response to changes in our understanding of human psychology—homosexuality, for example, was once considered a mental disorder. The authors settled on the Minnesota Multiphasic Personality Inventory. The test has been around for nearly a century and, despite having undergone changes to update phrasing, it hasn't received any major revisions, and the changes in questions can be controlled for.
The authors then focused on the literature (including graduate thesis records), where they searched for any studies in which the MMPI was administered to high school or college students. Any study that had at least 10 participants was included in the meta-analysis, which spanned the years from 1938 to 2007. All told, there were 117 studies that included over 60,000 college students, and 14 studies that surveyed a total of nearly 14,000 high school students.
The authors did control for a number of factors that might influence the trends, such as regional differences, and the increase in female and minority enrollment in colleges. To an extent, the high school trends, which mirrored those in college, controlled for this, and the authors were able to analyze male and female students separately (they showed no significant differences). They also point out that, although many minority groups have doubled their numbers in college, they were starting from pretty small values; as a result, most groups still account for less than 10 percent of the total enrollment. Finally, they also looked for regional differences, and failed to find them.
That said, there are a couple of additional things about the data that may limit the quality of the analysis. For starters, the high school samples aren't as well documented as the college-level one, and cover a shorter period of time. For the college students, there seems to be only a single data point prior to the mid-1940s, and that is a clear outlier on many of the measures of mental health, so the trends aren't quite as long and dramatic as the raw numbers might indicate. It's also worth noting that the majority of those surveyed were probably psychology students who were recruited through classes; they may not be representative of the larger student body. The other issue that stood out is that the number of students enrolled in a trial doesn't seem to have been considered, even though it might contribute to the presence of some of the outlying results.
Given these caveats, however, the data does show some clear trends towards increasing signs of psychological ill-health. Since the 1940s, college students' scores have risen by a standard deviation or more on the following portions of the test: Psychopathic Deviation, Paranoia, Schizophrenia, and Hypomania. Not surprisingly, this shift is driven in part because of a rise in the number of people scoring above the point that is generally considered a sign of a real mental illness. Nearly 40 percent of recent graduates, for example, scored above the cut-off on hypomania, and about a third did when it comes to schizophrenia.
These trends persisted even after the authors controlled for the possibility that the current generation of college students is simply more open about problems that have existed the whole time. Fortunately, the MMPI includes questions that provide a measure of whether participants are attempting to hide mental illness or make themselves look good. (Amusingly, one of these was described as follows: "The Lie [L] scale measures the tendency for participants to present themselves as highly virtuous.")
The authors used this data to test two potential explanations for the trends observed. They compared the data to the cyclical changes in the unemployment rate, which acted as a proxy for general financial uncertainty; that produced a poor fit. Since the 1960s, however, there has been a survey of college first years that asks whether becoming "well off financially" was important to them. The upward trend in this priority correlated nicely with the trends in psychological issues.
The authors argue that this focus on doing well financially has left students with a set of unreasonable expectations; various studies have indicated that a high percentage of students expect high salaries and advanced education, but American society simply doesn't offer that many of these opportunities. At the same time, many measures of community-involvement have dropped since the 1960s. The authors argue that this is a sign of a shift away from intrinsic to extrinsic values, although alternate interpretations are clearly possible (i.e., the severity of mental problems may be a result of the reduction in community support).
So, what to make of all of this? Although the underlying MMPI data isn't ideal, it's probably the best retrospective information we're going to get. And, although the trends probably aren't as large as the authors claim (given that the lone 1930s data point appears to be an outlier), they definitely seem real—if nothing else, there's clearly a lot more variability in these scores in recent decades.
The authors' explanation for the trend is plausible but, given the roughly linear trend in the MMPI scores, pretty much anything that also shows a linear trend would provide a nice fit. There's also a period between 1960 and 1980 where the data is sparse, which may obscure any cyclical trends. And, as noted above, cause and consequence can be very difficult to tease out when it comes to mental health. So, although the trend might be real, it's probably too early to pin the blame on rampant materialism, or any other single causative factor.
Clinical Psychology Review, 2009. DOI: 10.1016/j.cpr.2009.10.005